The document describes various data definition language (DDL) and data manipulation language (DML) commands in MySQL. Some key commands include using CREATE to add new databases, tables, indexes, and constraints. ALTER is used to modify existing database objects. DROP removes databases, tables, columns or indexes. DML commands like SELECT are used to query data, WHERE filters rows, JOIN combines tables, and INSERT, UPDATE, DELETE modify data. COUNT, SUM, DISTINCT and other functions can be used to aggregate or transform result sets.

1. A. DDL Commands on MySQL:
 Create a database
Create database [database name];
 To delete a db.
Drop database [database name];
 To delete a table.
Drop table [table name];
 Delete a column.
Alter table [table name] drop column [column name];
ALTER TABLE employee DROP INDEX name_dept; - get rid of
 Add a new column to db.
Alter table [table name] add column [new column name] varchar (20);
ALTER TABLE employee ADD EmpId INT NOT NULL AUTO_INCREMENT PRIMARY
KEY;
 Change column name.
Alter table [table name] change [old column name] [new column] varchar (50);
 Make a unique column so you get no dupes.
Alter table [table name] add unique ([column name]);
 Make a column bigger.

2. Alter table [table name] modify [column name] varchar (3);
 Delete unique from table.
Alter table [table name] drop index [column name];
 Delete data from specific fields within a column:
Mysql> DELETE FROM mytable WHERE mycolumn="mydata";
 Rename a table within a specific database
Mysql> RENAME TABLE first TO second;
(Or)
Mysql> ALTER TABLE mytable rename as mynewtable;
 Create Table Example 1.
Create table [table name] (first name varchar(20),middleintial varchar(3),last
name varchar(35),suffix varchar(3),officeid varchar(10),userid
varchar(15),username varchar(8),email varchar(35),phone varchar(25),groups
varchar(15),datestamp date,timestamp time,pagemail varchar(255));
CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20), species
VARCHAR(20), sex CHAR(1), birth DATE, death DATE);
CREATE TABLE retired_employee (Name char(20) DEFAULT '' NOT NULL,Dept
char(10) DEFAULT '' NOT NULL,JobTitle char(20)UNIQUE name_dept
(Name,Dept));
CREATE UNIQUE index name_dept on employee (name,dept); - avoids duplicate
keys
 Create Table Example 2.
Create table [tablename] (personid int(50) not null auto_increment primary
key,firstname varchar(35),middlename varchar(50),lastname char(50) default
‘bato’;

3. Create table employees (employee_id integer, first_name varchar (20), last_name
Varchar (20)) type=MyISAM;
 Drop Database
Drop database databasename;
 Delete a row(s) from a table.
DELETE from [tablename] where [fieldname]=’whatever’;
 DROP TABLE
DROP TABLE TABLENAME;
 Simple column and field manipulation
Show columns within a table:
Mysql> DESC mytable;
(Or)
Mysql> SHOW COLUMNS FROM mytable;
B. DML Commands :
 Show all data in a table
SELECT * FROM [TABLENAME];
 Show certain selected rows with the value “whatever”
SELECT * FROM [tablename] where [field] =”whatever”;
 Show all records containing the name "Bob" AND the phone number '3444444'.
SELECT * FROM [TABLENAME] WHERE NAME=”bob” AND
phone_number=’3444444’;

4.  Show all records not containing the name "Bob" AND the phone number
'3444444' order by the phone_number field.
SELECT * FROM [TABLENAME] WHERE NAME! =”bob” and
phone_number=’3444444’ order by phone_number;
 Show all records starting with the letters 'bob' AND the phone number '3444444'.
SELECT * FROM [TABLENAME] WHERE NAME LIKE “bob%” and
phone_number=’3444444’;
 Show all records starting with the letters 'bob' AND the phone number '3444444'
limit to records 1 through 5.
SELECT * FROM [TABLENAME] WHERE NAME LIKE “bob%” and
phone_number=’3444444’ limit 1,5;
 Use a regular expression to find records. Use "REGEXP BINARY" to force case-
sensitivity. This finds any record beginning with a.
SELECT * FROM [TABLENAME] WHERE rec RLIKE “^a”;
 Show unique records.
SELECT DISTINCT [column name] FROM [TABLE NAME];
 Show selected records sorted in an ascending (asc) or descending (desc).
Select [col1], [col2] from [tablename] order by [col2] desc;
 Return number of rows.
SELECT COUNT (*) FROM [TABLENAME];
 Is there a way to query the DB to find out how many rows there are in all the
tables?
SELECT TABLE_NAME, TABLE_ROWS FROM `information_schema`.`tables` WHERE
`table_schema` = 'mrsqa4';

5.  Is there a way to get the count of rows in all tables in a mysql database without
running a SELECT count () on each table?
SELECT SUM (TABLE_ROWS) FROM INFORMATION_SCHEMA.TABLESWHERE
TABLE_SCHEMA = 'mrsqa4';
 Sum column.
SELECT SUM (*) FROM [TABLENAME];
 Show the last 200 queries to your database with the sample table name "queries"
and the sample field "query_id"
Mysql> SELECT * FROM queries ORDER BY query_id DESC LIMIT 200;
 Show data within a specific table in a previously selected database
Mysql> SELECT * FROM table name;
 Select data within a specific table in a previously selected database:
Mysql> SELECT * FROM mytable WHERE mycolumn='mydata' ORDER BY
mycolumn2;
 Join tables on common columns.
Select lookup.illustrationid, looup.personid,person.birthday from lookup
Left join person on lookup.personid=person.personid=statement to join
Birthday in person table with primary illustrationid;
MySQL> SELECT DISTINCT dept FROM bedrock;
MySQL> SELECT * FROM pet WHERE species = "snake" OR species = "bird";
MySQL> SELECT * FROM pet WHERE species = "dog" AND sex = "f";
MySQL> SELECT * FROM pet WHERE birth >= "1998-1-1";
MySQL> SELECT name, birth FROM pet ORDER BY birth DESC;
MySQL> SELECT * FROM pet WHERE name LIKE "b%";
MySQL> SELECT * FROM pet WHERE name REGEXP "^b";

6. MySQL> SELECT species, COUNT(*) FROM pet GROUP BY species;
MySQL> SELECT MAX(article) AS article FROM shop;
MySQL> SELECT * FROM employee WHERE name LIKE "%Sm%";
MySQL> SELECT * FROM employee WHERE name REGEXP "^Ja";
Insert:
MySQL> INSERT INTO employee VALUES ("Jane Smith","Sales","Custome Rep");
MySQL> INSERT INTO employee VALUES ('Jane Smith','Sales','Account Manager');
MySQL> INSERT INTO employee VALUES ('Jane smith’,’Engineein’,’Manager’);
MySQL> UPDATE employee SET dept='HR' WHERE name='Jane Smith';
 Insert data into a table and its columns within a specific database:
mysql> INSERT INTO mytable VALUES('column1data','column2data',
'column3data','column4data','column5data','column6data',
'column7data','column8data','column9data');
 Update data in a specific table, column, field:
Mysql> UPDATE mytable SET column1="mydata" WHERE column2="mydata";