Presented by, Mr. Abhilash K Database Architect, Livares Technologies Introduction About DBMS A database management system (DBMS) is a software for creating and managing databases. DBMS provides users/programmers with a systematic way to create, retrieve, update and manage data. What is RDBMS A type of DBMS in which the database is organized and accessed according to the relationships between data values. RDBMS are designed to take care of large amounts of data and also the security of this data

1. Database Overview
Presented By
Abhilash K
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2. Contents
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3. Contents
8.SQL Functions
9.SQL Joins
10.SQL Sub Queries
11.Peformance Tuning
12.Advanced Concepts
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4. Introduction
About DBMS
A database management system (DBMS) is a software for
creating and managing databases. DBMS provides
users/programmers with a systematic way to create,
retrieve, update and manage data.
What is RDBMS
A type of DBMS in which the database is organized and
accessed according to the relationships between data
values. RDBMS are designed to take care of large amounts
of data and also the security of this data
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5. RDBMS Have
Tables (relations) that are two dimensional
The tables have rows (records or objects)
The tables have columns (fields or attributes)
The data stored is simple data such as integers, real
numbers, dates or string values
All table columns depend on a primary key to identify the
column
Database – collection of Tables and other objects.
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6. SQL
Structured Query Language
SQL Overview
➔ SQL is language component of the RDBMS
➔ SQL essentially has four components
SQL Has 4 essential components
➔ The data definition language : DDL
➔ The data manipulation language : DML
➔ The data control language : DCL
➔ The transaction control language : TCL
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7. SQL – Components 1
DDL – Statements used to define the database structure
or schema
➔ CREATE – Creates objects in the database
➔ ALTER – Alters the structure of the database
➔ DROP – Deletes the objects form the database
➔ TRUNCATE – Remove all records from a table, including all spaces
allocated for the records are removed
DML – Statements used to managing data with in schema
objects
➔ SELECT – Retrieve data from the database
➔ INSERT – Insert data into a table
➔ UPDATE - Updates existing data within a table
➔ DELETE - Deletes records from a table,the space for the records
remains
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8. SQL – Components 2
DCL – Statement used for data control
➔ GRANT – Give user’s access privileges to database
➔ REVOKE – Withdraw access privileges given the GRANT command
TCL – Manages the changes made by DML
statements
➔ COMMIT – Saves the work done
➔ SAVEPOINT – Identify a point in transaction to which you
can later rollback
➔ ROLLBACK – Restore database to original since the last
➔ SET TRANSACTION – Change transaction options like
isolation level and what rollback segment to use
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9. Database Table
Definition
➔ A two dimensional arrangements of rows and columns
used for holding data
A Table
➔ Has unique name
➔ Consists of rows and columns
➔ All values in one column have the same data type
➔ Every column can be used in an SQL statement
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10. Creating Table
Syntax
CREATE TABLE table_name
(column1 datatype null/not null,
column2 datatype null/not null,
…)
Each column must have a datatype. The column should
either be defined as "null" or "not null" and if this value is
left blank, the database assumes "null" as the default
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11. Creating Table
Specification
➔ NULL
➔ NOT NULL
➔ NOT NULL WITH DEFAULT
When creating a table,one of these attributes is specified for a column
NULL v/s NOT NULL
➔ NULL - Can be interpreted as unknown or not available
Null doesn’t mean empty (blank) or 0 (Zero)
➔ NOT NULL - The user must provide values while inserting a
row (0 or blank is allowed for these columns)
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12. Creating Table
NOT NULL WITH DEFAULT
The default value is stored,when a row is inserted without a specified
value for this column.
The default value is
Zero (0) for numeric data fields
Blank [empty] for character data fields
Current date for DATE fields
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13. Data Types
Common Data Types in MySQL
char varchar text bigint binary
blob bit int date datetime
decimal enum float numeric ntext
nvarchar nchar real double
mediumtext smallinttimestamp
datetime(x)
time
tinyintjson
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14. Integrity Constraints
Primary Key
Foreign Key
Unique Key
NOT NULL
Check
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15. Integrity Constraints
Primary Key
➔ A primary key is a single field or combination of fields
that uniquely defines a record
➔ A table can have only one primary key
➔ A primary key can be defined in either a CREATE TABLE
statement or an ALTER TABLE statement
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16. Integrity Constraints
Foreign Key
➔ A foreign key means that values in one table must also
appear in another table
➔ The foreign key in the child table will generally
reference a primary key in the parent table
➔ A foreign key can be defined in either a CREATE TABLE
statement or an ALTER TABLE statement
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17. Integrity Constraints
Unique Key
➔ A unique constraint is a single field or combination of
fields that uniquely defines a record.
➔ Some of the fields can contain null values as long as
the combination of values is unique.
➔ A unique constraint can be defined in either a CREATE
TABLE statement or an ALTER TABLE statement
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18. Integrity Constraints
What is the difference between Primary Key and Unique
Key?
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Primary Key Unique Constraint
None of the fields that are
part of the primary key can
contain a null value
Some of the fields that are
part of the unique
constraint can contain null
values as long as the
combination of values is
unique

19. Integrity Constraints
NOT NULL
➔ NOT NULL constraints are in-line constraints that
indicate that a column can not contain NULL values
CHECK
➔ Check constraints validate that values in a given
column meet a specific criteria
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20. IDE/Tools
MySQL Server Tools
➔ Toad for MySQL
➔ SQL Yog
➔ phpMyAdmin
➔ MySQL Administrator
➔ MySQL Query Browser
➔ MySQL WorkBench
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21. Structure of SQL Queries
SELECT - column names / arithmetic expressions / literals
/ scalar functions / column functions
FROM - table names or view names
WHERE - conditions
GROUP BY - column names
HAVING - conditions
ORDER BY - column names
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22. Table Aliases
Table Alias
➔ The use of table aliases means to rename a table in a
particular SQL statement
➔ The renaming is a temporary change
➔ The actual table name does not change in the
database
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23. Comparison Operators
In the WHERE clause
➔ Equal =
➔ Not Equal != or <>
➔ Less <
➔ Less or Equal < =
➔ Greater >
➔ Greater or Equal > =
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24. Boolean Operators
Boolean Operators
➔ AND
➔ OR
➔ NOT
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25. Additional Operators
Additional Operators
➔ IN
➔ NOT IN
➔ BETWEEN
➔ NOT BETWEEN
➔ LIKE
➔ NOT LIKE
➔ IS NULL
➔ IS NOT NULL
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26. Distinct
The DISTINCT clause
➔ Allows you to remove duplicates from the result set
➔ The DISTINCT clause can only be used with select
statements.
The syntax
➔ SELECT DISTINCT column_name FROM table_name
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27. Table Joins
JOIN
A join is used to combine rows from multiple tables
Different types of joins
➔ INNER JOIN
➔ OUTER JOIN
➢ LEFT JOIN
➢ RIGHT JOIN
➢ FULL JOIN
➔ CARTESIAN JOIN
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28. WHERE Clause
WHERE
The WHERE clause allows you to filter the results from an
SQL statement
E.g.
SELECT *
FROM supplier
WHERE supplier_name = ‘ABC’
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29. GROUP Functions
Group functions
Return results based on groups of rows, rather than on
single rows
Main Group functions
➔ COUNT
➔ SUM
➔ MIN
➔ MAX
➔ AVG
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30. GROUP Functions
COUNT function - returns the number of rows in a query
SELECT COUNT(expression) FROM table_name;
SUM Function - returns the summed value of an
expression
SELECT SUM(expression ) FROM table_name;
MIN Function - returns the minimum value of an
expression
SELECT MIN(expression ) FROM table_name;
MAX function - returns the maximum value of an
expression
SELECT MAX(expression ) FROM table_name;
AVG Function - returns the average value of an expression
SELECT AVG(expression) FROM table_name;
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31. Grouping
GROUP BY Clause
Can be used in a SELECT statement to collect data
across multiple records and group the results by one or
more columns
The syntax
SELECT column1,column2,
aggregate_function(expression)
FROM tables
WHERE predicates
GROUP BY column1, column2;
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32. Having Clause
HAVING clause
➔ Used in combination with the GROUP BY clause.
➔ It can be used in a SELECT statement to filter the
records that a GROUP BY returns.
The syntax :
SELECT column1, column2, ... column_n,
aggregate_function (expression)
FROM tables
WHERE predicates
GROUP BY column1, column2, ... column_n
HAVING condition1 ... condition_n;
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33. ORDER BY Clause
ORDER BY
Allows to sort the records in your result set
The ORDER BY clause can only be used in SELECT
statements
The syntax :
SELECT columns FROM table
WHERE predicate
ORDER BY column ASC/DESC;
ASC indicates ascending order. (default)
DESC indicates descending order.
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34. UNION and UNION ALL
UNION
➔ Allows to combine the result sets of 2 or more "select"
queries
➔ It removes duplicate rows between the various
"select" statements
➔ Each SQL statement within the UNION query must
have the same number of fields in the result sets with
similar data types
The syntax :
Select field1, field2, . field_n From tables
UNION
Select field1, field2, . field_n From tables;
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35. UNION and UNION ALL
UNION ALL
➔ Allows to combine the result sets of 2 or more "select“
queries
➔ It returns all rows (even if the row exists in more than
one of the "select" statements)
➔ Each SQL statement within the UNION ALL query
must have the same number of fields in the result
sets with similar data types
The syntax :
Select field1, field2, . field_n From tables
UNION ALL
Select field1, field2, . field_n From tables;
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36. Sub Query
Subquery
Is a query within a query [SELECT]
Different Types
➔ Stand alone [independent existence]
➔ Co-related [dependent on outer select]
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37. INSERT, UPDATE and DELETE
INSERT - Allows to insert a single record or multiple
records into a table.
INSERT INTO table (column-1, column-2, ... column-n)
VALUES (value-1, value-2, ... value-n);
UPDATE - Allows to update a single record or multiple
records in a table.
UPDATE table SET column = expression
WHERE predicate;
DELETE - Allows to delete a single record or multiple
records from a table.
DELETE FROM table WHERE predicate;
Note : “i-am-a-dummy” configuration
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38. Database Design-Thump Rule
A table generally should have an identifier.
A table should store only data for a single type of entity.
A table should avoid nullable columns.
Table should not have repeating values or columns.
Keep columns as short as possible. e.g. Use int for bigint
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39. Person Schema Design
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40. Person Schema Design
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41. Normalization
Normalizing a logical database design involves using
formal methods to separate the data into multiple, related
tables
A greater number of narrow tables (with fewer columns)
is characteristic of a normalized database
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42. Benefits of Normalization
Faster sorting and index creation.
A larger number of clustered indexes.
Narrower and more compact indexes.
Fewer indexes per table, which improves the performance
of INSERT, UPDATE, and DELETE statements.
Fewer null values and less opportunity for inconsistency,
which increase database compactness.
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43. INDEX
As the name indicates, indexes are used to speed up the
SELECT queries.
Types :
➔ Clustered : Created by default when a primary key is
created on the table.
➔ Non Clustered [Secondary] : All indexes other than the
clustered index are known as secondary indexes.
● Restrictions :
✔ A table can contain a maximum of 64 secondary indexes.
✔ A maximum of 16 columns only permitted for multicolumn
indexes.
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44. INDEX
Disadvantages :
✔ The index slows down the speed of writing queries, such
as INSERT, UPDATE and DELETE. So more number of
indexes will lead to sluggishness of write operations.
✔ when we create index, it takes up disk space. the index
file would grow much more quickly than the data file.
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45. Performance Tuning
EXPLAIN EXTENDED SELECT *
FROM stray_intakes
WHERE nid = 1209159 AND gid = 464;
table
➔ The table to which the row of output refers.
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46. Performance Tuning
type
The join type. Possible join types are listed below,
ranked fastest to slowest:
➔ system - The table is a system table with only one row.
➔ const - The table has at most one matching row. A const
query is fast because the table is read only once.
➔ eq_ref - No more than one row will be read from this table.
This type is used when all columns of an index are used in
the query, and the index is UNIQUE or a PRIMARY KEY.
➔ ref - All matching rows will be read from this table. This is
used when an index is neither UNIQUE nor a PRIMARY.
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47. Performance Tuning
➔ range - Only rows in a given range will be retrieved from
this table, using an index to select the rows.
➔ index - A full scan of the index will be performed for each
combination of rows from previous tables. This is the
same as an ALL join type except only the index is
scanned.
➔ ALL - A full scan of the table will be performed for each
combination of rows from previous tables. ALL joins
should be avoided by adding an index.
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48. Performance Tuning
possible_keys
Lists which indexes MySQL could use to find the rows
in this table. When there are no relevant indexes,
possible_keys is NULL. This indicates that you can improve
the performance of your query by adding an index.
key
Lists the actual index that MySQL chose. It is NULL if
no index was chosen.
rows
Lists the number of rows that MySQL needs to
examine from the table to execute the query.
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49. Advanced Concepts
Information_Schema
MySQL Engines
Stored Procedures, Functions, Views
Backup and Restore of Databases
MySQL Replication
MySQL Cluster
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50. 50
Thanks a lot for your time…
Questions?