Sql (Introduction to Structured Query language)
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Sql (Introduction to Structured Query language)

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Practical guide for a beginner who wants to learn SQL, which is a quite important language for working with any RDBMS (Relational Database Management System) like Oracle, MySql, DB2 etc..

Practical guide for a beginner who wants to learn SQL, which is a quite important language for working with any RDBMS (Relational Database Management System) like Oracle, MySql, DB2 etc..

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Sql (Introduction to Structured Query language) Document Transcript

  • 1. CREATE DATABASE database_name; Then create connection with database. The connection is included in the names of the database. Create a Table: the following query creates a table CREATE TABLE table_name ( column_name1 data_type, ....... ) CREATE TABLE email ( LName varchar(20), FName varchar(20), email_add varchar(40) ) INSERT INTO 'table_name'('field_name', 'field_name'. . .) VALUES ('field_value', 'field_value'. . .); INSERT INTO employee VALUES ('Amar', 'Designer', 10000, 'amar@roseindia.com'); The output of the above code will be: employee: emp_name Position Salary email_id Amar Designer 10000 amar@roseindia.com Insert Data in Specified Columns Let us consider we have a table named employee which have the following records: emp_name Position Salary email_id Amar Designer 10000 amar@roseindia.com Let us consider we want to insert data in field name 'emp_name', 'Position' and in 'email_id' with there specific values then we should use the following SQL statement: INSERT INTO employee (emp_name, Position, email_id) VALUES ('Vinod', 'Programmer', 'vinod@roseindia.com'); The output is like: emp_name Position Salary email_id Amar Designer 10000 amar@roseindia.com Vinod Programmer vinod@roseindia.com emp_name Position Salary email_id Amar Designer 8000 amar@roseindia.com If we want to change the salary to the employee with a emp_name of "Amar" then we should use the following SQL statement : Syntax: UPDATE 'table_name' SET 'field_name' = 'new_value' WHERE 'field_name' = 'field_value'; for example: UPDATE Person SET Salary = 10000 WHERE emp_name = 'Amar'; The output of the above code will be : emp_name Position Salary email_id Amar Designer 10000 amar@roseindia.com To Update several Columns in a Row: If we want to change the multiple values of a table like in employee table we want to change Position and email_id then we have to write the following code in which we set
  • 2. the email_id and position by SET keyword and putting condition by keyword WHERE for emp_name is 'Amar'. UPDATE employee SET email_id = 'amar@newsindia.com', Position = 'Programmer' WHERE emp_name = 'Amar'; The output of the above code will be: emp_name Position Salary email_id Amar Programmer 10000 amar@newsindia.com DELETE FROM table_name WHERE column_name = some_value Let's consider a table : Person: LName FName Address ram Raj delhi-5 sonu Shiv delhi-5 To Delete a Row : Suppose the row with Lname="sonu" is needed to get deleted DELETE FROM Person WHERE LName = 'sonu' Result LName FName Address ram Raj delhi-5 To Delete All the Rows : This means that the table structure, attributes, and indexes will be drop. DELETE FROM table_name SELECT column_name(s) FROM table_name Example: To select the content of columns named "LName" and "FName", from the database table called "email", use a SELECT . SELECT Name, Father_Name FROM EMAIL The database table "email": Name Father_Name Address Ram Sonu delhi-5 Select All Columns: To select all columns from the "email" table, use a * symbol instead of column names. SELECT * FROM email SELECT column FROM table WHERE column operator value The following operators can be used: Operator Description = Equal BETWEEN Between an inclusive range LIKE Search for a pattern IN If you know the exact value you want to return for at least one of the columns WHERE in SQL: we add a WHERE to the SELECT statement: SELECT * FROM Persons WHERE unit='india' In this section we are going to illustrate aggregate function, with the help of which we can use many arithmetic operation like average, count, maximum and many more in SQL. They are briefly described and denoted by the keyword in the given below section.
  • 3. AVG COUNT MAX MIN SUM For all of the above given function the standard code syntax will be: SELECT "function type" ("column_name") FROM "table_name" For example we just take a Employee table and use the aggregate function SUM on the field "Salary" to find out the total salary of the Employee table. Table Employee: emp_Name Salery Joining_Date Amit 15000 Feb-05-2005 Chandan 25000 Feb-17-2005 Ravi 8000 Feb-25-2005 Vinod 7000 Feb-28-2005 To find out the total salary of the company's employee we should write the following code: SELECT SUM (Salary) FROM Employee; When we run the above query we will get the following result: SUM(Salary) 55000 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(1,'Komal',10); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 1 Komal 10 SQL % Wildcards Syntax SELECT ColumnName(s) FROM TableName WHERE ColumnName LIKE pattern SQL % Wildcards Query Now we want to select the persons name those name starts with "k" from the table above. select * from Stu_Table where Stu_Name like 'k%' Result Stu_Id Stu_Name Stu_Class 1 Komal 10 1 Komal 10 Now we want to select the persons name those name ends with "h" from the table above. select * from Stu_Table where Stu_Name like '%h' Result Stu_Id Stu_Name Stu_Class 3 Rakesh 10
  • 4. 5 Santosh 10 reate Table Stu_Class_10 create table Stu_Class_10( Stu_Id integer(2) NOT NULL, Stu_Name varchar(15), Stu_Class varchar(10), UNIQUE (id)) Insert data into Stu_Class_10 insert into Stu_Class_10 values(1,'Komal',10); insert into Stu_Class_10 values(2,'Ajay',10); insert into Stu_Class_10 values(3,'Rakesh',10); insert into Stu_Class_10 values(4,'Bhanu',10); insert into Stu_Class_10 values(5,'Santosh',10); Stu_Class_10 Stu_Class_10 Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 Create Table Stu_Class_10 create table Stu_Class_10(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Create Table Stu_Class_12 create table Stu_Class_12(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Class_10 insert into Stu_Class_10 values(1,'Komal',10) insert into Stu_Class_10 values(2,'Ajay',10) insert into Stu_Class_10 values(3,'Rakesh',10) insert into Stu_Class_10 values(4,'Bhanu',10) insert into Stu_Class_10 values(5,'Santosh',10) insert into Stu_Class_10 values(1,'Komal',10) Insert data into Stu_Class_12 insert into Stu_Class_12 values(1,'Komal',12) insert into Stu_Class_12 values(1,'Komal',12) insert into Stu_Class_12 values(2,'Ajay',12) insert into Stu_Class_12 values(3,'Rakesh',12) insert into Stu_Class_12 values(4,'Bhanu',12) insert into Stu_Class_12 values(5,'Santosh',12) Stu_Class_10 Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 1 Komal 10 Stu_Class_12 Stu_Id Stu_Name Stu_Class 1 Komal 12 1 Komal 12 2 Ajay 12 3 Rakesh 12 4 Bhanu 12 5 Santosh 12 SQL UNION Syntax The SQL UNION Syntax used for union columns from two tables is given below: SELECT column_name(s) FROM table_name1 UNION All SELECT column_name(s) FROM table_name2 Use UNION in SQL Query
  • 5. In this example, we union columns from two different tables. The UNION ALL combine two table using select statement when both the table have the same name field and its data type. The select return you all duplicate records from both tables. The UNION ALL command select all records from a tables. .SELECT * FROM Stu_Class_10 UNION ALL SELECT * FROM Stu_Class_12 Result Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 1 Komal 10 1 Komal 12 1 Komal 12 2 Ajay 12 3 Rakesh 12 4 Bhanu 12 5 Santosh 12 Create Table Stu_Class_10 create table Stu_Class_10(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Create Table Stu_Class_12 create table Stu_Class_12(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Class_10 insert into Stu_Class_10 values(1,'Komal',10) insert into Stu_Class_10 values(2,'Ajay',10) insert into Stu_Class_10 values(3,'Rakesh',10) insert into Stu_Class_10 values(4,'Bhanu',10) insert into Stu_Class_10 values(5,'Santosh',10) Insert data into Stu_Class_12 insert into Stu_Class_12 values(1,'Komal',12) insert into Stu_Class_12 values(1,'Komal',12) insert into Stu_Class_12 values(2,'Ajay',12) insert into Stu_Class_12 values(3,'Rakesh',12) insert into Stu_Class_12 values(4,'Bhanu',12) insert into Stu_Class_12 values(5,'Santosh',12) Stu_Class_10 Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 Stu_Class_12 Stu_Id Stu_Name Stu_Class 1 Komal 12 1 Komal 12 2 Ajay 12 3 Rakesh 12 4 Bhanu 12 5 Santosh 12 SQL UNION Syntax The Syntax used for SQL UNION is used to selects only distinct values by default. The Syntax used for SQL UNION is given below:. SELECT column_name(s) FROM table_name1 UNION SELECT column_name(s) FROM table_name2 Use UNION in SQL Query In this example, we make use of UNION in SQL Query, The UNION query return you the set of distinct records from both the tables. The UNION operator only works with select statement, when both the table
  • 6. have same field name and data type. The given below Query return you the distinct value from both the tables. SELECT * FROM Stu_Class_10 UNION SELECT * FROM Stu_Class_12 Result Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 1 Komal 12 2 Ajay 12 3 Rakesh 12 4 Bhanu 12 5 Santosh 12 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)); Create Table Lib_Table create table Lib_Table(Stu_Id integer(2), Lib_no integer(5)); Insert data into Stu_Table insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(8,'Tanuj',10); Insert data into Lib_Table insert into Lib_Table values(1,101); insert into Lib_Table values(2,102); insert into Lib_Table values(3,103); insert into Lib_Table values(4,104); insert into Lib_Table values(5,105); insert into Lib_Table values(6,106); insert into Lib_Table values(7,107); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 8 Tanuj 10 Lib_Table Stu_Id Lib_no 1 101 2 102 3 103 4 104 5 105 6 106 7 107 SQL RIGHT JOIN Syntax The SQL RIGHT JOIN Syntax display you all the records from the right table, even there are no matches with the left table. The Syntax used for SQL RIGHT OUTER JOIN is given below: SELECT column_name(s) FROM table_name1 right JOIN table_name2 ON table_name1.column_name=table_name2.column_name Use Right JOIN in SQL Query
  • 7. The Example shows you the RIGHT JOIN in SQL Query. In this Example, we use RIGHT OUTER JOIN, which displays the records from two tables. The table contain return all record from table1,even there are no matches with the table 2. select s.stu_id, s.stu_name, s.stu_class, l.lib_no from stu_table as s Right JOIN lib_table as l on l.stu_id = s.stu_id Result Stu_Id Stu_Name Stu_Class Lib_No 1 Komal 10 101 2 Ajay 10 102 3 Rakesh 10 103 4 Bhanu 10 104 5 Santosh 10 105 NULL NULL NULL 106 NULL NULL NULL 107 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table The insert into add the records or rows value to the table 'Stu_Table'. insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(1,'Komal',10); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 1 Komal 10 SQL IN Syntax The SQL IN Syntax is used to return the records from table specify multiple values in WHERE Clause. SELECT ColumnName(s) FROM TableName WHERE ColumnName IN(value1, value2,...) SQL IN Query The given below Query return you the records from table stu_table specifying multiple value in Stu_Name containing name 'komal' and 'Rakesh'. SELECT Stu_Id, Stu_Name, Stu_Class FROM Stu_Table WHERE Stu_Name IN('Komal', 'Rakesh') Result Stu_Id Stu_Name Stu_Class 1 Komal 10 3 Rakesh 10 1 Komal 10 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10), Stu_Dob Date) Insert data into Stu_Table insert into Stu_Table values(1,'Komal',10,'1999,11,1'); insert into Stu_Table values(2,'Ajay',10,'1999,10,1'); insert into Stu_Table values(3,'Rakesh',10,'1999,11,1'); insert into Stu_Table values(4,'Bhanu',10,'1999,11,1'); insert into Stu_Table values(5,'Santosh',10,'1999,11,1'); Stu_Table Stu_Id Stu_Name Stu_Class Stu_Dob
  • 8. 1 Komal 10 1999-11-1 2 Ajay 10 1999-10-1 3 Rakesh 11 1999-11-1 4 Bhanu 11 1999-11-1 5 Santosh 12 1999-11-1 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(1,'Komal',10); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 1 Komal 10 SQL LIKE Syntax The SQL BETWEEN operator helps you to return a records between two values. The Syntax used in SQL Like is given below: SELECT ColumnName(s) FROM TableName WHERE ColumnName value1 between value2 SQL Like Operator Query The SQL Like Operator Query is used to select the Stu_Table where a stu_Id between 1 and 3 from the table. SELECT Stu_Id, Stu_Name, Stu_Class FROM Stu_Table WHERE Stu_Id BETWEEN 1 and 3 Result Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 1 Komal 10 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(1,'Komal',11); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 1 Komal 11 SQL AND Operator Syntax The SQL AND Operator Syntax return you a filter records or rows from a table based on condition. The Syntax used for SQL AND Operator is given as : SELECT columnName(s)
  • 9. FROM tableName where condition1 AND conditions2 SQL AND Operator Query The given SQL Query uses SQL AND Operator to fetch the record from table 'Stu_Table' based upon where clause, which restricts the records from table based upon the AND operator condition. The AND operator query return you a record only ,if the both condition specified in query are true. Otherwise, no records fetch from a table. SELECT Stu_Id, Stu_Name, Stu_Class FROM Stu_Table where Stu_Id = 1 AND Stu_name = 'komal' Result Stu_Id Stu_Name Stu_Class 1 Komal 10 1 Komal 11 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table values(1,'Komal',10) insert into Stu_Table values(2,'Ajay',12) insert into Stu_Table values(3,'Rakesh',12) insert into Stu_Table values(4,'Bhanu',12) insert into Stu_Table values(5,'Santosh',12) insert into Stu_Table values(1,'Komal',10) Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 12 3 Rakesh 12 4 Bhanu 12 5 Santosh 12 1 Komal 10 SQL AND Operator Syntax The SQL AND Operator Syntax return you the filter record from a table based upon the condition specified in the query. SELECT columnName(s) FROM tableName where condition1 AND conditions2 SQL AND Operator Query The given SQL Query help you to select only the Stu_Table with the Stu_Id equal to"1" AND Stu_class="10".The AND operator fetch the records from a table, if both the condition are to be true. In case, any one of the condition is false, fetch no records from table. SELECT Stu_Id, Stu_Name, Stu_Class FROM Stu_Table where Stu_Id = 1 AND Stu_Class = 10 Result Stu_Id Stu_Name Stu_Class 1 Komal 10 1 Komal 10 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table values(1,'Komal',10) insert into Stu_Table values(2,'Ajay',10) insert into Stu_Table values(3,'Rakesh',10) insert into Stu_Table values(4,'Bhanu',10) insert into Stu_Table values(5,'Santosh',10) insert into Stu_Table values(1,'Komal',10) Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10
  • 10. 4 Bhanu 10 5 Santosh 10 1 Komal 10 Syntax The below Syntax helps you to fetch the records from the table. The Like query is used to find and search for a specified records from a table in database.. SELECT ColumnName(s) FROM TableName WHERE ColumnName LIKE pattern Query The given below Query fetch the record from table 'Stu_Table using WHERE clause, which restrict the records based upon the Like Query, that is used to find and search for a specific records from a table Stu_Table. The % (wildcard) is used to specify wildcards, which indicates missing letters in the pattern before and after the pattern. In this code, we want to select the Stu_Table begin with a stu_name "k" whose id is"1".The AND operator is used to satisfy the both condition. If the both condition is true returns you a record from table. The record display a Stu_Name begin with "k" whose id is "1". select * from Stu_Table where stu_name like 'k%'AND stu_id = 1 Result Stu_Id Stu_Name Stu_Class 1 Komal 10 1 Komal 10 1. Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 SQL Alter Query Alter table Stu_Table rename to Stu_Table_10) 2. Create Table Stu_Table create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(10), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table (Stu_Id, Stu_Name) values(1,'Komal'); insert into Stu_Table (Stu_Id, Stu_Name) values(2,'Ajay'); insert into Stu_Table (Stu_Id, Stu_Name) values(3,'Rakesh'); insert into Stu_Table (Stu_Id, Stu_Name) values(4,'Bhanu'); insert into Stu_Table (Stu_Id, Stu_Name) values(5,'Santosh'); Stu_Table +--------+----------+-----------+ | Stu_Id | Stu_Name | Stu_Class | +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 |
  • 11. | 4 | Bhanu | 10 | | 5 | Santosh | 10 | +--------+----------+-----------+ Describe Stu_Table The Describe Stu_Table show you the field, data type, null etc of the table 'Stu_Table'. +-----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+---------+-------+ | Stu_Id | varchar(2) | YES | | | | | Stu_Name | varchar(10) | YES | | | | | Stu_Class | varchar(10) | YES | | | | +-----------+-------------+------+-----+---------+-------+ Alter column type Query The Alter Table alter the table 'stu_Table' and MODIFY keywords modify the data type of Stu_Id(varchar (2)) into Stu_Id( int(3)). ALTER TABLE Stu_Table MODIFY Stu_Id int(3) Describe Stu_Table When you see the structure of table using Describe Stu_Table, the output is displayed as: +-----------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+--------------+------+-----+---------+-------+ | Stu_Id | int(3) | YES | | | | | Stu_Name | varchar(10) | YES | | | | | Stu_Class | varchar(10) | YES | | | | +-----------+--------------+------+-----+---------+-------+ Create Table Stu_Table create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table (Stu_Id, Stu_Name) values(1,'Komal'); insert into Stu_Table (Stu_Id, Stu_Name) values(2,'Ajay'); insert into Stu_Table (Stu_Id, Stu_Name) values(3,'Rakesh'); insert into Stu_Table (Stu_Id, Stu_Name) values(4,'Bhanu'); insert into Stu_Table (Stu_Id, Stu_Name) values(5,'Santosh'); Stu_Table +--------+----------+-----------+ | Stu_Id | Stu_Name | Stu_Class | +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | +--------+----------+-----------+ Describe Stu_Table +-----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+---------+-------+ | Stu_Id | varchar(2) | YES | | | | | Stu_Name | varchar(15) | YES | | | | | Stu_Class | varchar(10) | YES | | | | +-----------+-------------+------+-----+---------+-------+ Alter Column Size Query ALTER TABLE Stu_Table MODIFY Stu_Id varchar(100) Describe Stu_Table +-----------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+--------------+------+-----+---------+-------+ | Stu_Id | varchar(100) | YES | | | | | Stu_Name | varchar(15) | YES | | | | | Stu_Class | varchar(10) | YES | | | | +-----------+--------------+------+-----+---------+-------+
  • 12. Create Table Stu_Table create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(10), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table (Stu_Id, Stu_Name) values(1,'Komal'); insert into Stu_Table (Stu_Id, Stu_Name) values(2,'Ajay'); insert into Stu_Table (Stu_Id, Stu_Name) values(3,'Rakesh'); insert into Stu_Table (Stu_Id, Stu_Name) values(4,'Bhanu'); insert into Stu_Table (Stu_Id, Stu_Name) values(5,'Santosh'); Stu_Table +--------+----------+-----------+ | Stu_Id | Stu_Name | Stu_Class | +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | +--------+----------+-----------+ Describe Stu_Table +-----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+---------+-------+ | Stu_Id | varchar(2) | YES | | | | | Stu_Name | varchar(10) | YES | | | | | Stu_Class | varchar(10) | YES | | | | +-----------+-------------+------+-----+---------+-------+ Alter column Not Null Query ALTER TABLE Stu_Table MODIFY Stu_Id int(3)not null Describe Stu_Table +-----------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+--------------+------+-----+---------+-------+ | Stu_Id | int(3) | No | | | | | Stu_Name | varchar(10) | YES | | | | | Stu_Class | varchar(10) | YES | | | | +-----------+--------------+------+-----+---------+-------+ Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10) ) Insert data into Stu_Table insert into Stu_Table (Stu_Id, Stu_Name) values(1,'Komal'); insert into Stu_Table (Stu_Id, Stu_Name) values(2,'Ajay'); insert into Stu_Table (Stu_Id, Stu_Name) values(3,'Rakesh'); insert into Stu_Table (Stu_Id, Stu_Name) values(4,'Bhanu'); insert into Stu_Table (Stu_Id, Stu_Name) values(5,'Santosh'); Stu_Table +--------+----------+-----------+ | Stu_Id | Stu_Name | Stu_Class | +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | +--------+----------+-----------+ Syntax The ALTER table statement in SQL is used to modify the table 'Stu_Table' and change keyword change the name of field to new name of field. The syntax used for Alter Table is given below: Alter table table_name change old_column_name new_column_name type size Query The Alter Table alter the table 'Stu_Table'. The change keyword change the column name of Stu_Id to Id in table 'Stu_Table'. Alter table Stu_Table change Stu_Id Id varchar(10)
  • 13. Stu_Table +--------+----------+-----------+ | Id | Stu_Name | Stu_Class | +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | +--------+----------+-----------+ Create Table Stu_Table create table Stu_Table( Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table insert into Stu_Table (Stu_Id, Stu_Name) values(1,'Komal'); insert into Stu_Table (Stu_Id, Stu_Name) values(2,'Ajay'); insert into Stu_Table (Stu_Id, Stu_Name) values(3,'Rakesh'); insert into Stu_Table (Stu_Id, Stu_Name) values(4,'Bhanu'); insert into Stu_Table (Stu_Id, Stu_Name) values(5,'Santosh'); Stu_Table +--------+----------+-----------+ | Stu_Id | Stu_Name | Stu_Class | +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | +--------+----------+-----------+ Describe Stu_Table +-----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+---------+-------+ | Stu_Id | varchar(10) | YES | | | | | Stu_Name | varchar(10) | YES | | NULL | | | Stu_Class | varchar(5) | YES | | NULL | | +-----------+-------------+------+-----+---------+-------+ Alter column Column Default Query The Alter Table Keywords modify table'Stu_Table' and MODIFY keyword modify the data type of field Stu_Id (varchar(10)) to Stu_Id(int(3)) and set the default value for this field is set '10'.Whenever you leave a blank value in Stu_Id, This field would take default value of '10'. ALTER TABLE Stu_Table MODIFY Stu_Id int(3) Default '10' Describe Stu_Table +-----------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+--------------+------+-----+---------+-------+ | Stu_Id | int(3) | No | | 10 | | | Stu_Name | varchar(10) | YES | | NULL | | | Stu_Class | varchar(5) | YES | | NULL | | +-----------+--------------+------+-----+---------+-------+ Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table The insert into insert the records or row values into table 'Stu_Table'. insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(6,'Tanuj',10); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10
  • 14. 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 6 Tanuj 10 SQL ALTER Syntax The SQL ALTER Syntax is used to modify the table and add a column name that you want to add and its data type. ALTER TABLE table_name ADD column_name column-definition SQL ALTER Query The given below Query alter a table 'Stu_Table' and add keyword add a column Stu_Class whose data type is varchar type. Alter Table Stu_Table add Stu_Class varchar(10) View data Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal NULL 2 Ajay NULL 3 Rakesh NULL 4 Bhanu NULL 5 Santosh NULL Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Create Table Lib_Table create table Lib_Table(Stu_Id integer(2), Lib_no integer(5)) Insert data into Stu_Table The insert into add the records or rows to the table 'Stu_Table' and 'Lib_Table'. insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); Insert data into Lib_Table insert into Lib_Table values(1,101) insert into Lib_Table values(2,102) insert into Lib_Table values(3,103) insert into Lib_Table values(4,104) insert into Lib_Table values(5,105) Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 Lib_Table Stu_Id Lib_no 1 101 2 102 3 103 4 104 5 105 SQL Alias Query The given below SQL Query takes alias name for table 'Stu_Table' as s and 'Lib_Table' as l. select s.stu_id, s.stu_name, s.stu_class, l.lib_no from Stu_Table as s , Lib_Table as l where s.stu_id = l.stu_id Result Stu_Id Stu_Name Stu_Class Lib_no 1 Komal 10 101 2 Ajay 10 102
  • 15. 3 Rakesh 11 103 4 Bhanu 11 104 5 Santosh 12 105 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15)) Insert data into Stu_Table insert into Stu_Table values(1,'Komal') insert into Stu_Table values(2,'Ajay') insert into Stu_Table values(3,'Rakesh') insert into Stu_Table values(4,'Bhanu') insert into Stu_Table values(5,'Santosh) Stu_Table Stu_Id Stu_Name 1 Komal 2 Ajay 3 Rakesh 4 Bhanu 5 Santosh SQL Add Column Syntax The ALTER Table is used to modify table name 'table_name' and add a column at the specific position. The first column specify the position of the column to be come first in table followed by a after column in a table. The Syntax is given as : ALTER TABLE table_name ADD column_name column-definition [ FIRST | AFTER col_name ] SQL Add Colum Query The SQL Add Column Query add a Stu_Name column followed by Stu_Name in the Table Stu_Table. Alter Table Stu_Table add Stu_Class int(10) AFTER Stu_Name View data Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal NULL 2 Ajay NULL 3 Rakesh NULL 4 Bhanu NULL 5 Santosh NULL Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15)) Insert data into Stu_Table insert into Stu_Table values(1,'Komal'); insert into Stu_Table values(2,'Ajay'); insert into Stu_Table values(3,'Rakesh'); insert into Stu_Table values(4,'Bhanu'); insert into Stu_Table values(5,'Santosh); Stu_Table Stu_Id Stu_Name 1 Komal 2 Ajay 3 Rakesh 4 Bhanu 5 Santosh SQL Add Column Syntax The ALTER TABLE is used to alter the table table_name.The Add keyword is used to add a new column in a table. ALTER TABLE table_name ADD column_name column-definition SQL Add Colum Query The given below example shows you a modified Stu_Table using Alter keywords, which add a new column Stu_Class using add keyword, whose data is integer type. Alter Table Stu_Table add Stu_Class int(10) View data Stu_Table
  • 16. Stu_Id Stu_Name Stu_Class 1 Komal NULL 2 Ajay NULL 3 Rakesh NULL 4 Bhanu NULL 5 Santosh NULL Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10) default '10') Insert data into Stu_Table insert into Stu_Table (Stu_Id, Stu_Name) values(1,'Komal'); insert into Stu_Table (Stu_Id, Stu_Name) values(2,'Ajay'); insert into Stu_Table (Stu_Id, Stu_Name) values(3,'Rakesh'); insert into Stu_Table (Stu_Id, Stu_Name) values(4,'Bhanu'); insert into Stu_Table (Stu_Id, Stu_Name) values(5,'Santosh'); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15)) Insert data into Stu_Table The insert into add the records or rows into the table 'Stu_Table'. insert into Stu_Table values(1,'Komal'); insert into Stu_Table values(2,'Ajay'); insert into Stu_Table values(3,'Rakesh'); insert into Stu_Table values(4,'Bhanu'); insert into Stu_Table values(5,'Santosh); Stu_Table Stu_Id Stu_Name 1 Komal 2 Ajay 3 Rakesh 4 Bhanu 5 Santosh SQL Add Column Syntax The Alter Table modifies and ADD Keywords add a new column to the table. The Syntax for the Add Column is given as below: ALTER TABLE table_name ADD column_name column-definition SQL Add Colum Query The given below Query define a Alter Table that modifies and add a new column 'Stu_Class' to the table 'Stu_Table'. Alter Table Stu_Table add Stu_Class varchar(10) View data Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal NULL 2 Ajay NULL 3 Rakesh NULL 4 Bhanu NULL 5 Santosh NULL Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)); Insert data into Stu_Table insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10);
  • 17. insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(1,'Komal',10); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 1 Komal 10 SQL LIKE Syntax SELECT ColumnName(s) FROM TableName WHERE ColumnName LIKE pattern SQL Like Operator Query Now we want to select the persons name those name starts with "k" from the table above. select * from Stu_Table where stu_name like 'k%' Result Stu_Id Stu_Name Stu_Class 1 Komal 10 1 Komal 10 Now we want to select the persons name those name ends with "h" from the table above. select * from Stu_Table where stu_name like '%h' Result Stu_Id Stu_Name Stu_Class 3 Rakesh 10 5 Santosh 10 create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)); Insert data into Stu_Table The Insert into statement add the records or rows into table 'Stu_Table'. SQL statement to insert data into table: insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(3,'Bhanu',10); insert into Stu_Table values(4,'Santosh',10); Stu_Table The Select statement return you the records from a table 'Stu_Table'. Records in the table: Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 SQL SELECT DISTINCT Syntax The SQL Distinct clause can be used with the Select statement to get all unique records from database SELECT DISTINCT columnName(s) FROM tableName SQL SELECT DISTINCT Query You can run the following query to retrieve unique records from the table: SELECT DISTINCT Stu_Id, Stu_Name, Stu_Class FROM Stu_Table; Result of the above query: Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10
  • 18. 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Create Table Lib_Table create table Lib_Table(Stu_Id integer(2), Lib_no integer(5)) Insert data into Stu_Table The insert into add the records or rows to the respective tables. insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(6,'Tanuj',10); Insert data into Lib_Table insert into Lib_Table values(1,101) insert into Lib_Table values(2,102) insert into Lib_Table values(3,103) insert into Lib_Table values(4,104) insert into Lib_Table values(5,105) Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 6 Tanuj 10 Lib_Table Stu_Id Lib_no 1 101 2 102 3 103 4 104 5 105 SQL INNER JOIN Syntax The INNER JOIN keyword is used to returns all rows from the left table (table_name1), even if there are no matches in the right table (table_name2).The syntax for SQL INNER JOIN is given as : SELECT column_name(s) FROM table_name1 Left JOIN table_name2 ON table_name1.column_name=table_name2.column_name Use INNER JOIN in SQL Query In this example, the inner join is used to return the records from a tables 'Stu_Table'and 'Lib_Table' using select statement. The select statement include the set of column records to be retrieved from both tables. The Left Join is used to return all rows from the left table ,even if there is no matches in the right table. select s.stu_id, s.stu_name, s.stu_class, l.lib_no from stu_table as s Left JOIN lib_table as l on l.stu_id = s.stu_id Ruselt Stu_Id Stu_Name Stu_Class Lib_No 1 Komal 10 101 2 Ajay 10 102 3 Rakesh 10 103 4 Bhanu 10 104 5 Santosh 10 105 6 Tanuj 10 NULL Create Table Stu_Class_10 CREATE TABLE Stu_Class_10( Stu_Id integer(2) NOT NULL,
  • 19. Stu_Name varchar(15) NOT NULL, Stu_Class varchar(10)) NOT NULL) Insert data into Stu_Class_10 table insert into Stu_Class_10 values(1,'Komal',10); insert into Stu_Class_10 values(2,'Ajay',10); insert into Stu_Class_10 values(3,'Rakesh',10); insert into Stu_Class_10 values(4,'Bhanu',10); insert into Stu_Class_10 values(5,'Santosh',10); Stu_Class_10 Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table Insert into statement insert the records into table. insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(1,'Komal',10); Stu_Table The select statement return you the record from table 'Stu_Table'. Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 1 Komal 10 SQL ORDER BY Syntax The ORDER BY keyword sort the table result set by a specified column. SELECT ColumnName(s) FROM TableName ORDER BY ColumnName(s) SQL ORDER BY Query In this Example, we use Order By Query on table 'Stu_Table'.The Order by Query return you the sorted records from the table in ascending order by Stu_Name. SELECT Stu_Id, Stu_Name, Stu_Class FROM Stu_Table ORDER BY Stu_Name Result output of the above SQL Query will be Stu_Id Stu_Name Stu_Class 2 Ajay 10 4 Bhanu 10 1 Komal 10 1 Komal 10 3 Rakesh 10 5 Santosh 10 SQL ORDER BY Query In this example, we sort the records from a table in descending order by Stu_Id. SELECT Stu_Id, Stu_Name, Stu_Class FROM Stu_Table ORDER BY Stu_Id DESC
  • 20. Result Stu_Id Stu_Name Stu_Class 5 Santosh 10 4 Bhanu 10 3 Rakesh 10 2 Ajay 10 1 Komal 10 1 Komal 10 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table The insert into add the records or rows to the table Stu_Table. insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',11); insert into Stu_Table values(4,'Bhanu',11); insert into Stu_Table values(5,'Santosh',12); insert into Stu_Table values(1,'Komal',10); Stu_Table The select statement help you to display the table detail. Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 11 4 Bhanu 11 5 Santosh 12 1 Komal 10 SQL OR Operator Syntax The SQL OR Operator is used to return a record if either the first condition is true or the second condition is true. The Syntax used for SQL OR Operator is given below: SELECT columnName(s) FROM tableName where condition1 OR conditions2 SQL OR Operator Query In this example, we make use of OR Operator, which return the records from a table on the basis of condition in WHERE Clause. The OR Operator return you a set of records,if either of the condition are true. SELECT Stu_Id, Stu_Name, Stu_Class FROM Stu_Table where Stu_Id = 1 OR Stu_Class = 10 Result Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 1 Komal 11 Create Table Stu_Class_10 create table Stu_Class_10( Stu_Id integer(2) NOT NULL, Stu_Name varchar(15), Stu_Class varchar(10), PRIMARY KEY(Stu_Id)) Insert data into Stu_Class_10 The insert into statement is used to add the records or rows to the table 'Stu_Class_10'. insert into Stu_Class_10 values(1,'Komal',10) insert into Stu_Class_10 values(2,'Ajay',10) insert into Stu_Class_10 values(3,'Rakesh',10) insert into Stu_Class_10 values(4,'Bhanu',10) insert into Stu_Class_10 values(5,'Santosh',10) Stu_Class_10 Stu_Id Stu_Name Stu_Class 1 Komal 10
  • 21. 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)) Create Table Lib_Table create table Lib_Table(Stu_Id integer(2), Lib_no integer(5)) Insert data into Stu_Table The insert into add the records or rows to the respective tables. insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); Insert data into Lib_Table insert into Lib_Table values(1,101); insert into Lib_Table values(2,102); insert into Lib_Table values(3,103); insert into Lib_Table values(4,104); insert into Lib_Table values(5,105); insert into Lib_Table values(6,106); Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 Lib_Table Stu_Id Lib_no 1 101 2 102 3 103 4 104 5 105 6 106 SQL INNER JOIN Syntax The INNER JOIN keyword in SQL is used to returns you a row, when there is at least one match in both table used in SQL Query. The Syntax used for SQL INNER JOIN is used as : SELECT column_name(s) FROM table_name1 INNER JOIN table_name2 ON table_name1.column_name=table_name2.column_name Use INNER JOIN in SQL Query In this example, we make use of inner join. The inner join return you the records from both table ,when there is atleast one match in both table respectively. The inner join is known as join. In this Query,both the tables have stu_id as primary key, based on it, return all the record from the column enlisted in select statement. select s.stu_id, s.stu_name, s.stu_class, l.lib_no from stu_table as s inner JOIN lib_table as l on l.stu_id = s.stu_id Ruselt Stu_Id Stu_Name Stu_Class Lib_No 1 Komal 10 101 2 Ajay 10 102 3 Rakesh 10 103 4 Bhanu 10 104 5 Santosh 10 105 Create Table Stu_Table create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)); Create Table Lib_Table
  • 22. create table Lib_Table(Stu_Id integer(2), Lib_no integer(5)); Insert data into Stu_Table The insert into add the records value into your respective tables. insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); Insert data into Lib_Table insert into Lib_Table values(1,101); insert into Lib_Table values(2,102); insert into Lib_Table values(3,103); insert into Lib_Table values(4,104); insert into Lib_Table values(5,105) Stu_Table Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 Lib_Table Stu_Id Lib_no 1 101 2 102 3 103 4 104 5 105 SQL Alias Query The given below example show you the SQL Alias Query. In this case, the alias name for Stu_Table is 's' and Lib_Table is 'l'.As you can see the Alias Name Query make the table name simple and easier to write and read. select s.stu_id, s.stu_name, s.stu_class, l.lib_no from Stu_Table as s , Lib_Table as l where s.stu_id = l.stu_id Result Stu_Id Stu_Name Stu_Class Lib_no 1 Komal 10 101 2 Ajay 10 102 3 Rakesh 11 103 4 Bhanu 11 104 5 Santosh 12 105 Create Table Stu_Table Create Table Stu_Table (Stu_Id varchar(2), Stu_Name varchar(15), Stu_Dob date); Insert Data Into Stu_Table The insert into statement add the records or rows into the table 'stu_table'. insert into stu_table values('1', 'komal', '1984-10-27'); insert into stu_table values('2', 'ajay', '1985-04-19'); insert into stu_table values('3', 'santosh', '1986-11-16'); Stu_Table +--------+----------+------------+ | Stu_Id | Stu_Name | Stu_Dob | +--------+----------+------------+ | 1 | komal | 1984-10-27 | | 2 | ajay | 1985-04-19 | | 3 | santosh | 1986-11-16 | +--------+----------+------------+ Query The given below Query return you the record from a table 'Stu_Table'. The Where Query restrict select Query and show you the record between ' '1984-01-01' And '1986-1-1'. Select * From Stu_Table
  • 23. Where Stu_Dob Between '1984-01-01' And '1986-1-1'; Result +--------+----------+------------+ | Stu_Id | Stu_Name | Stu_Dob | +--------+----------+------------+ | 1 | komal | 1984-10-27 | | 2 | ajay | 1985-04-19 | +--------+----------+------------+ create table statement create a table Stu_Table. Create Table Stu_Table SQL statement to create table : create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10),sub_id varchar(2),marks varchar(3)); Insert Data into Stu_Table The insert into statement add the records or rows to the table 'Stu_Table'. SQL statement to insert data into table: insert into Stu_Table values(1,'Komal',10,1,45); insert into Stu_Table values(2,'Ajay',10,1,56); insert into Stu_Table values(3,'Rakesh',10,1,67); insert into Stu_Table values(1,'Komal',10,2,47); insert into Stu_Table values(2,'Ajay',10,2,53); insert into Stu_Table values(3,'Rakesh',10,2,57); insert into Stu_Table values(1,'Komal',10,3,45); insert into Stu_Table values(2,'Ajay',10,3,56); insert into Stu_Table values(3,'Rakesh',10,3,67); insert into Stu_Table values(1,'Komal',10,4,65); insert into Stu_Table values(2,'Ajay',10,4,56); insert into Stu_Table values(3,'Rakesh',10,4,37); insert into Stu_Table values(1,'Komal',10,5,65); insert into Stu_Table values(2,'Ajay',10,5,46); insert into Stu_Table values(3,'Rakesh',10,5,63); Stu_Table Records in the table: +--------+----------+-----------+--------+-------+ | Stu_Id | Stu_Name | Stu_Class | sub_id | marks | +--------+----------+-----------+--------+-------+ | 1 | Komal | 10 | 1 | 45 | | 2 | Ajay | 10 | 1 | 56 | | 3 | Rakesh | 10 | 1 | 67 | | 1 | Komal | 10 | 2 | 47 | | 2 | Ajay | 10 | 2 | 53 | | 3 | Rakesh | 10 | 2 | 57 | | 1 | Komal | 10 | 3 | 45 | | 2 | Ajay | 10 | 3 | 56 | | 3 | Rakesh | 10 | 3 | 67 | | 1 | Komal | 10 | 4 | 65 | | 2 | Ajay | 10 | 4 | 56 | | 3 | Rakesh | 10 | 4 | 37 | | 1 | Komal | 10 | 5 | 65 | | 2 | Ajay | 10 | 5 | 46 | | 3 | Rakesh | 10 | 5 | 63 | +--------+----------+-----------+--------+-------+ Query The given below syntax show you the average marks records of a numeric field in a table. The Group By clause is used with the SQL aggregate functions and indicates the group where selected rows are placed. select stu_id, stu_name,GROUP_CONCAT(marks) as marks, sum(marks)as total ,avg(marks) as per from stu_table group by stu_id; Result +--------+----------+----------------+-------+------+ | stu_id | stu_name | marks | total | per |
  • 24. +--------+----------+----------------+-------+------+ | 1 | Komal | 45,65,47,65,45 | 267 | 53.4 | | 2 | Ajay | 56,56,56,53,56 | 277 | 55.4 | | 3 | Rakesh | 67,57,67,67,63 | 321 | 64.2 | +--------+----------+----------------+-------+------+ SQL statement to create table: create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10),sub_id varchar(2),marks varchar(3)); Insert Data into Stu_Table The insert into add the records or rows to the created table 'Stu_Table'. SQL statement to insert data into table: insert into Stu_Table values(1,'Komal',10,1,45); insert into Stu_Table values(2,'Ajay',10,1,56); insert into Stu_Table values(3,'Rakesh',10,1,67); insert into Stu_Table values(1,'Komal',10,2,47); insert into Stu_Table values(2,'Ajay',10,2,53); insert into Stu_Table values(3,'Rakesh',10,2,57); insert into Stu_Table values(1,'Komal',10,3,45); insert into Stu_Table values(2,'Ajay',10,3,56); insert into Stu_Table values(3,'Rakesh',10,3,67); insert into Stu_Table values(1,'Komal',10,4,65); insert into Stu_Table values(2,'Ajay',10,4,56); insert into Stu_Table values(1,'Komal',10,5,65); insert into Stu_Table values(3,'Rakesh',10,5,63); Stu_Table Records in the table: +--------+----------+-----------+--------+-------+ | Stu_Id | Stu_Name | Stu_Class | sub_id | marks | +--------+----------+-----------+--------+-------+ | 1 | Komal | 10 | 1 | 45 | | 2 | Ajay | 10 | 1 | 56 | | 3 | Rakesh | 10 | 1 | 67 | | 1 | Komal | 10 | 2 | 47 | | 2 | Ajay | 10 | 2 | 53 | | 3 | Rakesh | 10 | 2 | 57 | | 1 | Komal | 10 | 3 | 45 | | 2 | Ajay | 10 | 3 | 56 | | 3 | Rakesh | 10 | 3 | 67 | | 1 | Komal | 10 | 4 | 65 | | 2 | Ajay | 10 | 4 | 56 | | 1 | Komal | 10 | 5 | 65 | | 3 | Rakesh | 10 | 5 | 63 | +--------+----------+-----------+--------+-------+ Query The given below Query return you the records from table 'Stu_Table' and aggregate count for the table field 'stu_name'. The Group By clause in this Query is used with aggregate functions and also specifies the group 'stu_id' where selected rows are placed. select stu_id, stu_name, count(stu_name) from stu_table group by stu_id; Result +--------+----------+-----------------+ | stu_id | stu_name | count(stu_name) | +--------+----------+-----------------+ | 1 | Komal | 5 | | 2 | Ajay | 4 | | 3 | Rakesh | 4 | +--------+----------+-----------------+ Create Table Stu_Table SQL statement to create table: create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10)) Insert data into Stu_Table SQL statement to insert data into table: insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10);
  • 25. insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(6,'Tanuj',10); Stu_Table Records in the table: Stu_Id Stu_Name Stu_Class 1 Komal 10 2 Ajay 10 3 Rakesh 10 4 Bhanu 10 5 Santosh 10 6 Tanuj 10 Describe Stu_Table +-----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+---------+-------+ | Stu_Id | varchar(2) | NO | | | | | Stu_Name | varchar(15) | YES | | | | | stu_class | varchar(10) | NO | | | | +-----------+-------------+------+-----+---------+-------+ Alter Table Primary Key Syntax The table_name is the name of the table on which primary key is added. The column_name is the name of the column on which primary key is created. ALTER TABLE table_name ADD PRIMARY KEY (column_name) Alter Table Primary Key Query The given Query show you an example to alter a table name 'Stu_Table' on which primary key is added. The 'Stu_Id' is the name of the column on which primary key is created. ALTER TABLE Stu_Table ADD PRIMARY KEY (Stu_Id) Describe Stu_Table +-----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+---------+-------+ | Stu_Id | varchar(2) | NO | PRI | | | | Stu_Name | varchar(15) | YES | | | | | stu_class | varchar(10) | NO | | | | +-----------+-------------+------+-----+---------+-------+ reate Table SQL statement to create table: create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10)); Insert Data SQL statement to insert data into table: insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(6,'Tanuj',10); Describe Stu_Table +-----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+---------+-------+ | Stu_Id | varchar(2) | YES | | | | | Stu_Name | varchar(15) | YES | | | | | Stu_Class | varchar(10) | YES | | | | +-----------+-------------+------+-----+---------+-------+ Stu_Table Records in the table: +--------+---------- +-----------+ | Stu_Id | Stu_Name | Stu_Class |
  • 26. +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | | 6 | Tanuj | 10 | +--------+----------+-----------+ Add Multiple Columns Query The Alter Table Query in SQL modifies the existing table 'Stu_Table' and add a multiple columns to the existing table. In this example, we add columns 'Stu_dob' and 'Stu_Address' to the existing table 'Stu_Table'. Alter Table Stu_Table add (Stu_dob date, Stu_Addreass varchar(20)); Describe Stu_Table The Describe Stu_Table show you the new fields added to the table'Stu_Table'. +--------------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------------+-------------+------+-----+---------+-------+ | Stu_Id | varchar(2) | YES | | | | | Stu_Name | varchar(15) | YES | | | | | Stu_Class | varchar(10) | YES | | | | | Stu_dob | date | YES | | | | | Stu_Addreass | varchar(20) | YES | | | | +--------------+-------------+------+-----+---------+-------+ Stu_Table +--------+----------+-----------+---------+--------------+ | Stu_Id | Stu_Name | Stu_Class | Stu_dob | Stu_Addreass | +--------+----------+-----------+---------+--------------+ | 1 | Komal | 10 | | | | 2 | Ajay | 10 | | | | 3 | Rakesh | 10 | | | | 4 | Bhanu | 10 | | | | 5 | Santosh | 10 | | | | 6 | Tanuj | 10 | | | +--------+----------+-----------+---------+--------------+ Create Table Stu_Table create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10),sub_id varchar(2),marks varchar(3)); Insert Data into Stu_Table The insert into add the records or rows to the table'Stu_Table'. insert into Stu_Table values(1,'Komal',10,1,45); insert into Stu_Table values(2,'Ajay',10,1,56); insert into Stu_Table values(3,'Rakesh',10,1,67); insert into Stu_Table values(1,'Komal',10,2,47); insert into Stu_Table values(2,'Ajay',10,2,53); insert into Stu_Table values(3,'Rakesh',10,2,57); insert into Stu_Table values(1,'Komal',10,3,45); insert into Stu_Table values(2,'Ajay',10,3,56); insert into Stu_Table values(3,'Rakesh',10,3,67); insert into Stu_Table values(1,'Komal',10,4,65); insert into Stu_Table values(2,'Ajay',10,4,56); insert into Stu_Table values(3,'Rakesh',10,4,37); insert into Stu_Table values(1,'Komal',10,5,65); insert into Stu_Table values(2,'Ajay',10,5,46); insert into Stu_Table values(3,'Rakesh',10,5,63); Stu_Table +--------+----------+-----------+--------+-------+ | Stu_Id | Stu_Name | Stu_Class | sub_id | marks | +--------+----------+-----------+--------+-------+ | 1 | Komal | 10 | 1 | 45 | | 2 | Ajay | 10 | 1 | 56 | | 3 | Rakesh | 10 | 1 | 67 | | 1 | Komal | 10 | 2 | 47 | | 2 | Ajay | 10 | 2 | 53 | | 3 | Rakesh | 10 | 2 | 57 |
  • 27. | 1 | Komal | 10 | 3 | 45 | | 2 | Ajay | 10 | 3 | 56 | | 3 | Rakesh | 10 | 3 | 67 | | 1 | Komal | 10 | 4 | 65 | | 2 | Ajay | 10 | 4 | 56 | | 3 | Rakesh | 10 | 4 | 37 | | 1 | Komal | 10 | 5 | 65 | | 2 | Ajay | 10 | 5 | 46 | | 3 | Rakesh | 10 | 5 | 63 | +--------+----------+-----------+--------+-------+ Query The given below Query display you the records from table 'Stu_Table'. The 'sum(marks)' in the select statement compute the sum of marks. The Group By Clause in this query returns you the group of result-set by column name'stu_id'. select stu_id, stu_name, sum(marks) as 'total marks' from stu_table group by stu_id; Result +--------+----------+-------------+ | stu_id | stu_name | total marks | +--------+----------+-------------+ | 1 | Komal | 267 | | 2 | Ajay | 267 | | 3 | Rakesh | 291 | +--------+----------+-------------+ Create Table Stu_Table create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10),sub_id varchar(2),marks varchar(3)); Insert Data into Stu_Table The Insert into statement add the records or rows to the table 'Stu_Table'. insert into Stu_Table values(1,'Komal',10,1,45); insert into Stu_Table values(2,'Ajay',10,1,56); insert into Stu_Table values(3,'Rakesh',10,1,67); insert into Stu_Table values(1,'Komal',10,2,47); insert into Stu_Table values(2,'Ajay',10,2,53); insert into Stu_Table values(3,'Rakesh',10,2,57); insert into Stu_Table values(1,'Komal',10,3,45); insert into Stu_Table values(2,'Ajay',10,3,56); insert into Stu_Table values(3,'Rakesh',10,3,67); insert into Stu_Table values(1,'Komal',10,4,65); insert into Stu_Table values(2,'Ajay',10,4,56); insert into Stu_Table values(3,'Rakesh',10,4,37); insert into Stu_Table values(1,'Komal',10,5,65); insert into Stu_Table values(2,'Ajay',10,5,46); insert into Stu_Table values(3,'Rakesh',10,5,63); Stu_Table +--------+----------+-----------+-------- +-------+ | Stu_Id | Stu_Name | Stu_Class | sub_id | marks | +--------+----------+-----------+--------+-------+ | 1 | Komal | 10 | 1 | 45 | | 2 | Ajay | 10 | 1 | 56 | | 3 | Rakesh | 10 | 1 | 67 | | 1 | Komal | 10 | 2 | 47 | | 2 | Ajay | 10 | 2 | 53 | | 3 | Rakesh | 10 | 2 | 57 | | 1 | Komal | 10 | 3 | 45 | | 2 | Ajay | 10 | 3 | 56 | | 3 | Rakesh | 10 | 3 | 67 | | 1 | Komal | 10 | 4 | 65 | | 2 | Ajay | 10 | 4 | 56 | | 3 | Rakesh | 10 | 4 | 37 | | 1 | Komal | 10 | 5 | 65 | | 2 | Ajay | 10 | 5 | 46 | | 3 | Rakesh | 10 | 5 | 63 | +--------+----------+-----------+--------+-------+
  • 28. Query The Query below returns you the records from select statement. The GROUPCONCAT is used to combine the result value of field. The max(marks) compute the maximum value of the field 'marks'. select stu_id, stu_name, GROUP_CONCAT(marks) as marks , max(marks) from stu_table group by stu_id Result +--------+----------+----------------+------------+ | stu_id | stu_name | marks | max(marks) | +--------+----------+----------------+------------+ | 1 | Komal | 45,65,47,65,45 | 65 | | 2 | Ajay | 46,56,56,53,56 | 56 | | 3 | Rakesh | 67,57,37,67,63 | 67 | +--------+----------+----------------+------------+ Create Table Stu_Table create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10),sub1 integer(2),sub2 integer(2), sub3 integer(2),sub4 integer(2),sub5 integer(2)); Insert Value Into Stu_Table The insert into statement add the records or rows to the table. insert into Stu_Table values(1, 'Komal', 10, 23, 34, 45, 56, 67); insert into Stu_Table values(2, 'Ajay', 10, 34, 45, 56, 67, 78); insert into Stu_Table values(3, 'Rakesh', 10, 23, 43, 45, 45, 34); insert into Stu_Table values(4, 'Bhanu', 10, 56, 45, 67, 34, 54); insert into Stu_Table values(5, 'Santosh', 10, 56, 67, 56, 67, 56); insert into Stu_Table values(6, 'Tanuj', 10, 56, 45, 56, 56, 45); Stu_Table +--------+----------+-----------+------+------+------+------ +------+ | Stu_Id | Stu_Name | Stu_Class | sub1 | sub2 | sub3 | sub4 | sub5 | +--------+----------+-----------+------+------+------+------+------+ | 1 | Komal | 10 | 23 | 34 | 45 | 56 | 67 | | 2 | Ajay | 10 | 34 | 45 | 56 | 67 | 78 | | 3 | Rakesh | 10 | 23 | 43 | 45 | 45 | 34 | | 4 | Bhanu | 10 | 56 | 45 | 67 | 34 | 54 | | 5 | Santosh | 10 | 56 | 67 | 56 | 67 | 56 | | 6 | Tanuj | 10 | 56 | 45 | 56 | 56 | 45 | +--------+----------+-----------+------+------+------+------+------+ Query The given below Query returns you the records enlisted in select statement and sum of different numeric field for each individual group of column values in the table 'Stu_Table'. select stu_id, stu_name, sub1, sub2, sub3, sub4, sub5, sum( sub1 + sub2 + sub3 + sub4 + sub5) as total from stu_table group by stu_id; Result +--------+----------+------+------+------+------+------+-------+ | stu_id | stu_name | sub1 | sub2 | sub3 | sub4 | sub5 | total | +--------+----------+------+------+------+------+------+-------+ | 1 | Komal | 23 | 34 | 45 | 56 | 67 | 225 | | 2 | Ajay | 34 | 45 | 56 | 67 | 78 | 280 | | 3 | Rakesh | 23 | 43 | 45 | 45 | 34 | 190 | | 4 | Bhanu | 56 | 45 | 67 | 34 | 54 | 256 | | 5 | Santosh | 56 | 67 | 56 | 67 | 56 | 302 | | 6 | Tanuj | 56 | 45 | 56 | 56 | 45 | 258 | +--------+----------+------+------+------+------+------+-------+ create the Table Stu_Table SQL statement to create table: create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)); Insert data into Stu_Table Insert into keyword add the records or rows to the table 'Stu_Table'. SQL statement to insert data into table: insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10);
  • 29. insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(6,'Tanuj',10); insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); Stu_Table Records in the table: +--------+----------+-----------+ | Stu_Id | Stu_Name | Stu_Class | +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | | 6 | Tanuj | 10 | | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | | 1 | Komal | 10 | | 2 | Ajay | 10 | +--------+----------+-----------+ Query The given Query return you the records and retrieve a single value, by calculate from values in a column 'stu_name' enlisted in the select statement from 'Stu_Table'. The group by keyword group all the records which is grouped by attribute 'stu_id' from a table 'Stu_Table'. select stu_name,count(stu_name) from stu_table group by stu_id; Result +----------+-----------------+ | stu_name | count(stu_name) | +----------+-----------------+ | Komal | 4 | | Ajay | 6 | | Rakesh | 5 | | Bhanu | 5 |
  • 30. | Santosh | 4 | | Tanuj | 1 | +----------+-----------------+ Create the Table Stu_Table SQL statement to create table: create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class varchar(10)); Insert data into Stu_Table Insert into keywords in SQL add the records or rows to the table 'Stu_Table'. SQL statement to insert data into table: insert into Stu_Table values(1,'Komal',10); insert into Stu_Table values(2,'Ajay',10); insert into Stu_Table values(3,'Rakesh',10); insert into Stu_Table values(4,'Bhanu',10); insert into Stu_Table values(5,'Santosh',10); insert into Stu_Table values(6,'Tanuj',10); Stu_Table Records in the table: +--------+---------- +-----------+ | Stu_Id | Stu_Name | Stu_Class | +--------+----------+-----------+ | 1 | Komal | 10 | | 2 | Ajay | 10 | | 3 | Rakesh | 10 | | 4 | Bhanu | 10 | | 5 | Santosh | 10 | | 6 | Tanuj | 10 | +--------+----------+-----------+ Query Next, the given below Query want to return the conditionally select the data from a table 'Stu_Table'. For example, we want to retrieve the maximum value of the 'stu_id' with name search specified in the 'Stu_Name'. In order to overcome, we use the WHERE clause. The Syntax is given below: select max(stu_id) from stu_table where stu_name in('komal','ajay','santosh','rakesh'); Result +-------------+ | max(stu_id) | +-------------+ | 5 | +-------------+ Create Table Stu_Table create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10),sub_id varchar(2),marks varchar(3)); Insert Data into Stu_Table The insert into statement add the records or rows to the table 'Stu_Table'. insert into Stu_Table values(1,'Komal',10,1,45); insert into Stu_Table values(2,'Ajay',10,1,56); insert into Stu_Table values(3,'Rakesh',10,1,67); insert into Stu_Table values(1,'Komal',10,2,47); insert into Stu_Table values(2,'Ajay',10,2,53); insert into Stu_Table values(3,'Rakesh',10,2,57); insert into Stu_Table values(1,'Komal',10,3,45); insert into Stu_Table values(2,'Ajay',10,3,56); insert into Stu_Table values(3,'Rakesh',10,3,67); insert into Stu_Table values(1,'Komal',10,4,65); insert into Stu_Table values(2,'Ajay',10,4,56); insert into Stu_Table values(3,'Rakesh',10,4,37); insert into Stu_Table values(1,'Komal',10,5,65); insert into Stu_Table values(2,'Ajay',10,5,46); insert into Stu_Table values(3,'Rakesh',10,5,63); Stu_Table +--------+----------+-----------+--------+-------+ | Stu_Id | Stu_Name | Stu_Class | sub_id | marks | +--------+----------+-----------+--------+-------+
  • 31. | 1 | Komal | 10 | 1 | 45 | | 2 | Ajay | 10 | 1 | 56 | | 3 | Rakesh | 10 | 1 | 67 | | 1 | Komal | 10 | 2 | 47 | | 2 | Ajay | 10 | 2 | 53 | | 3 | Rakesh | 10 | 2 | 57 | | 1 | Komal | 10 | 3 | 45 | | 2 | Ajay | 10 | 3 | 56 | | 3 | Rakesh | 10 | 3 | 67 | | 1 | Komal | 10 | 4 | 65 | | 2 | Ajay | 10 | 4 | 56 | | 3 | Rakesh | 10 | 4 | 37 | | 1 | Komal | 10 | 5 | 65 | | 2 | Ajay | 10 | 5 | 46 | | 3 | Rakesh | 10 | 5 | 63 | +--------+----------+-----------+--------+-------+ Query The Query return you a records and concatenated values from the field 'marks' from table 'Stu_table'. The group by return the group records from a table 'Stu_Table'. select stu_id,stu_name,GROUP_CONCAT(marks) as marks from stu_table group by stu_id; Result +--------+----------+----------------+ | stu_id | stu_name | marks | +--------+----------+----------------+ | 1 | Komal | 45,65,47,65,45 | | 2 | Ajay | 46,56,56,53,56 | | 3 | Rakesh | 67,57,37,67,63 | +--------+----------+----------------+ Create Table Stu_Table SQL statement to create table: create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10), sub_id varchar(2), marks varchar(3)); Insert Data into Stu_Table The insert into add the records or rows to the table 'Stu_Table'. SQL statement to insert data into table: insert into Stu_Table values(1,'Komal',10,1,45); insert into Stu_Table values(2,'Ajay',10,1,56); insert into Stu_Table values(3,'Rakesh',10,1,67); insert into Stu_Table values(1,'Komal',10,2,47); insert into Stu_Table values(2,'Ajay',10,2,53); insert into Stu_Table values(3,'Rakesh',10,2,57); insert into Stu_Table values(1,'Komal',10,3,45); insert into Stu_Table values(2,'Ajay',10,3,56); insert into Stu_Table values(3,'Rakesh',10,3,67); insert into Stu_Table values(1,'Komal',10,4,65); insert into Stu_Table values(2,'Ajay',10,4,56); insert into Stu_Table values(3,'Rakesh',10,4,37); insert into Stu_Table values(1,'Komal',10,5,65); insert into Stu_Table values(2,'Ajay',10,5,46); insert into Stu_Table values(3,'Rakesh',10,5,63); Stu_Table Records in the table: +--------+----------+-----------+--------+-------+ | Stu_Id | Stu_Name | Stu_Class | sub_id | marks | +--------+----------+-----------+--------+-------+ | 1 | Komal | 10 | 1 | 45 | | 2 | Ajay | 10 | 1 | 56 | | 3 | Rakesh | 10 | 1 | 67 | | 1 | Komal | 10 | 2 | 47 | | 2 | Ajay | 10 | 2 | 53 | | 3 | Rakesh | 10 | 2 | 57 | | 1 | Komal | 10 | 3 | 45 | | 2 | Ajay | 10 | 3 | 56 | | 3 | Rakesh | 10 | 3 | 67 |
  • 32. | 1 | Komal | 10 | 4 | 65 | | 2 | Ajay | 10 | 4 | 56 | | 3 | Rakesh | 10 | 4 | 37 | | 1 | Komal | 10 | 5 | 65 | | 2 | Ajay | 10 | 5 | 46 | | 3 | Rakesh | 10 | 5 | 63 | +--------+----------+-----------+--------+-------+ Drop Table Query The Drop Table Query delete the table 'Stu_Table' from database. The Table 'Stu_Table' is no longer to be present in database. Drop Table Stu_Table;