MYSQL COMMANDS

1)To login (from unix shell) use -h only if needed.
—->[mysql dir]/bin/mysql -h hostname -u root -p

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2)Create a database on the sql server.
—-> create database [databasename];
—->eg :- create database college;

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3)List all databases on the sql server.
—-> show databases;

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4)Switch to a database.
—–> use [databasename];

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5)To see all the tables in the database.
——->show tables

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6) To see database’s field formats.
—–> desc [table name];

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7)To delete a db.
—> drop database [database name];
eg:- drop database college;

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8)To create a table.
—–>CREATE table tablename(field_one datatype(size),fiels_two datatype(size));

eg1:-mysql> CREATE TABLE student( id INT(20),name VARCHAR(100));
Query OK, 0 rows affected (0.03 sec)

eg:-2 mysql> CREATE TABLE [table name] (firstname VARCHAR(20), middleinitial VARCHAR(3), lastname 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,pgpemail VARCHAR(255));
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9)Creating a table with auto_increment

—> CREATE TABLE tablename(field_one datatype(size) NOT NULL AUTO_INCREMENT PRIMARY KEY , field_two datatype(size));

eg:-mysql> CREATE TABLE student (id INT(10) NOT NULL AUTO_INCREMENT PRIMARY KEY, name VARCHAR(100) );
Query OK, 0 rows affected (0.01 sec)

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10)Creating a table with the current timestamp
—> CREATE TABLE student ( id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
data VARCHAR(100), cur_timestamp TIMESTAMP(7) );

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11Creating a table with TIMESTAMP DEFAULT NOW()

—> CREATE TABLE student (
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(100), created TIMESTAMP DEFAULT NOW());

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12)Viewing a table definition
—-> DESC tablename;

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13)To delete a table.
—–> drop table [table name];
eg) drop table student;

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14)INSERT values into table
—–>INSERT INTO [tablename] (filed_one,field_two,feild_three) values(value1,value2,value3);

eg:-INSERT INTO student (id,name,branch) values(1,’Amit’,'computer science’);

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15)Change a users password.(from unix shell).
—->mysql dir]/bin/mysqladmin -u root -h hostname.blah.org -p password ‘new-password’

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16)Change a users password.(from MySQL prompt).
—-> SET PASSWORD FOR ‘user’@'hostname’ = PASSWORD(‘passwordhere’);

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17)GRANT privileges
—–>grant all privileges on [databasename].* to user@’localhost’ identified by ‘passwd’;

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18)GRANT specific privileges
—-> GRANT SELECT ON databasename.* TO username@’localhost’ IDENTIFIED BY ‘password’;

To enable more options you would separate them with a comma. So to enable SELECT, INSERT, and DELETE your syntax would look like this;

—–>GRANT SELECT, INSERT, DELETE ON database.* TO username@’localhost’ IDENTIFIED BY ‘password’;

Once you have given the desired privileges for your user, you will need to run this command within the MySQL command prompt;

—–>FLUSH PRIVILEGES;

To see a list of the privileges that have been granted to a specific user;

—–> select * from MySQL.user where User=’user’ \G

This is a list of privileges that you can grant;

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19)To update info already in a table.
—-> Update table tablename SET fieldname=newvalue where fieldname=oldvalue;
eg1:- Update table student set id=2 where id=2;
eg2:- Update table student set name=’Arun’ where name=’Amit’;

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20) Modify an existing field in a table
—-> update table table name MODIFY fieldname(new size);
eg:- Update table tablename MODIFY id(30);

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21)Delete a row(s) from a table.
—> DELETE from [table name] where [field name] = ‘value’;

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22)Delete a column.
—->alter table [table name] drop column [column name];

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23)Add a new column to db.
—–> alter table [table name] add column [new column name] varchar (20);

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24)Change column name.
—-> alter table [table name] change [old column name] [new column name] varchar (50);

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25)Make a unique column so you get no dupes.
—-> alter table [table name] add unique ([column name]);

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26)Make a column bigger.
—-> alter table [table name] modify [column name] VARCHAR(3);

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27)Select values from a table

To see alla values of a table use

SELECT * from tablename;

To select specific values from a table use

SELECT fieldname_one,fieldname_two from tablename;

To select fields based on condition

SELECT fieldname_one,fieldname_two from tablename where [condition];

eg:-SELECT id from student where name=’Arun’;

28 ) Dump a table from a database

[mysql dir]/bin/mysqldump -c -u username -ppassword databasename tablename > /tmp/databasename.tablename.sql

29)Restore database (or database table) from backup.
[mysql dir]/bin/mysql -u username -ppassword databasename < /tmp/databasename.sql