First where your mysql is

which mysql

To login (from unix shell) use -h only if needed.

mysql -u root -p
or
[mysql dir]/bin/mysql -h hostname -u username -p
// on Mac MAMP:
/Applications/MAMP/Library/bin/mysql -u root -p

To login (from windows)

mysql dir/bin/mysql.exe -h hostname -u username -ppassword

Creating a new user. Login as root. Switch to the MySQL db. Make the user. Update privs.

# mysql -u root -p
mysql> use mysql;
mysql> INSERT INTO user (Host,User,Password) VALUES('%','username',PASSWORD('password'));
mysql> flush privileges;

Change a users password from unix shell.

# [mysql dir]/bin/mysqladmin -u username -h hostname -ppassword 'new-password'

Change a users password from MySQL prompt. Login as root. Set the password. Update privileges.

mysql> SET PASSWORD FOR 'user'@'hostname' = PASSWORD('password');
mysql> flush privileges;

Recover a MySQL root password. Stop the MySQL server process. Start again with no grant tables. Login to MySQL as root. Set new password. Exit MySQL and restart MySQL server.

# /etc/init.d/mysql stop
# mysqld_safe --skip-grant-tables
# mysql -u root
mysql> use mysql;
mysql> update user set password=PASSWORD("newpassword") where User='root';
mysql> flush privileges;
mysql> quit
# /etc/init.d/mysql stop
# /etc/init.d/mysql start

Set a root password if there is no root password.

# mysqladmin -u root password newpassword

Update a root password.

# mysqladmin -u root -p oldpassword newpassword

Allow the user "Someone" to connect to the server from localhost using the password "passwd". Login as root. Switch to the MySQL db. Give privs. Update privs.

> mysql -u root -p
mysql> use mysql;
mysql> grant usage on *.* to Someone@localhost identified by 'passwd';
mysql> flush privileges;

Give user privilages for a db. Login as root. Switch to the MySQL db. Grant privs. Update privs.

# mysql -u root -p
mysql> use mysql;
mysql>INSERT INTO user(Host,Db,User,Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv)
 VALUES ('%','databasename','username','Y','Y','Y','Y','Y','N');
mysql> flush privileges;

or

mysql> grant all privileges on databasename.* to username@localhost;
mysql> flush privileges;

Create a database.

mysql> create database [databasename];

List all databases on the server.

mysql> show databases;

Switch to a database.

mysql> use [db name];

To see all the tables in the db.

mysql> show tables;

To see table's field formats.

mysql> describe [table name];

To delete a db.

mysql> drop database [database name];

To delete a table.

mysql> drop table [table name];

Show all data from a table.

mysql> SELECT * FROM [table name];

To return columns and column information.

mysql> show columns from [table name];

Show particular rows with the given value.

mysql> SELECT * FROM [table name] WHERE [field name] = "value";

Show all records containing the name "Something" AND the phone number '0123456789'.

mysql> SELECT * FROM [table name] WHERE name = "Something" AND phone_number = '0123456789';

Show all records not containing the name "Something" AND the phone number '0123456789' order by the phone_number field.

mysql> SELECT * FROM [table name] WHERE name != "Something" AND phone_number = '0123456789' order by phone_number;

Show all records starting with the letters 'Something' AND the phone number '0123456789'.

mysql> SELECT * FROM [table name] WHERE name like "Something%" AND phone_number = '0123456789';

Show all records starting with letters 'Something' AND the phone number '0123456789' limit to records 1 through 5.

mysql> SELECT * FROM [table name] WHERE name like "Something%" AND phone_number = '0123456789' limit 1,5;

Use a regular expression to find records. Use "REGEXP BINARY" to force case-sensitivity. This finds any record beginning with a.

mysql> SELECT * FROM [table name] WHERE rec RLIKE "^a";

Show unique records.

mysql> SELECT DISTINCT [column name] FROM [table name];

Show selected records sorted in an ascending (asc) or descending (desc).

mysql> SELECT [col1],[col2] FROM [table name] ORDER BY [col2] DESC;

Return number of rows.

mysql> SELECT COUNT(*) FROM [table name];

Sum column.

mysql> SELECT SUM(*) FROM [table name];

To update info already in a table.

mysql> UPDATE [table name] SET Select_priv = 'Y',Insert_priv = 'Y',Update_priv = 'Y' where [field name] = 'user';

Delete a row(s) from a table.

mysql> DELETE from [table name] where [field name] = 'fieldvalue';

Update database permissions/privilages.

mysql> flush privileges;

Delete a column.

mysql> alter table [table name] drop column [column name];

Add a new column to db.

mysql> alter table [table name] add column [new column name] varchar (20);

Change column name.

mysql> alter table [table name] change [old column name] [new column name] varchar (50);

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

Make a column bigger.

mysql> alter table [table name] modify [column name] VARCHAR(3);

Delete unique from table.

mysql> alter table [table name] drop index [colmn name];

Load a CSV file into a table.

mysql> LOAD DATA INFILE '/tmp/filename.csv' replace INTO TABLE [table name] FIELDS TERMINATED BY ',' LINES TERMINATED BY '\n' (field1,field2,field3);

Dump all databases for backup. Backup file is sql commands to recreate all db's.

# mysqldump -u username -ppassword --opt > /tmp/alldatabases.sql

Dump one database for backup.

# mysqldump -u username -ppassword --databases databasename > /tmp/databasename.sql

Dump a table from a database.

# mysqldump -u username -ppassword databasename tablename > /tmp/databasename.tablename.sql

Restore database (or database table) from backup.

# mysql -u username -ppassword databasename < /tmp/databasename.sql

Create Table Example 1.

mysql> CREATE TABLE [table name] (name VARCHAR(20));

Create Table Example 2.

mysql> create table [table name] (personid int(50) not null auto_increment primary key,firstname varchar(35),middlename varchar(50),lastnamevarchar(50) default 'somethiing');