Mysql

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

# [mysql dir]/bin/mysql -h hostname -u root -p

 

Create a database on the sql server.

mysql> create database [databasename];

 

List all databases on the sql 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 database’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 in a table.

mysql> SELECT * FROM [table name];

 

Returns the columns and column information pertaining to the designated table.

mysql> show columns from [table name];

 

Show certain selected rows with the value “whatever”.

mysql> SELECT * FROM [table name] WHERE [field name] = “whatever”;

 

Show all records containing the name “Bob” AND the phone number ’3444444′.

mysql> SELECT * FROM [table name] WHERE name = “Bob” AND phone_number = ’3444444′;

 

Show all records not containing the name “Bob” AND the phone number ’3444444′ order by the phone_number field.

mysql> SELECT * FROM [table name] WHERE name != “Bob” AND phone_number = ’3444444′ order by phone_number;

 

Show all records starting with the letters ‘bob’ AND the phone number ’3444444′.

mysql> SELECT * FROM [table name] 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.

mysql> SELECT * FROM [table name] 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.

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];

 

Join tables on common columns.

mysql> select lookup.illustrationid, lookup.personid,person.birthday from lookup left join person on lookup.personid=person.personid=statement to join birthday in person table with primary illustration id;

 

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.blah.org -p password ‘new-password’

 

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

# mysql -u root -p
mysql> SET PASSWORD FOR ‘user’@'hostname’ = PASSWORD(‘passwordhere’);
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(“newrootpassword”) 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 on root password.

# mysqladmin -u root password newpassword

 

Update a root password.

# mysqladmin -u root -p oldpassword newpassword

 

Allow the user “bob” 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 bob@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 db (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;

 

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] = ‘whatever’;

 

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 dupelicates.

mysql> 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.

# [mysql dir]/bin/mysqldump -u root -ppassword –opt >/tmp/alldatabases.sql

 

Dump one database for backup.

# [mysql dir]/bin/mysqldump -u username -ppassword –databases databasename >/tmp/databasename.sql

 

Dump a table from a database.

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

 

Restore database (or database table) from backup.

# [mysql dir]/bin/mysql -u username -ppassword databasename < /tmp/databasename.sql

 

Create Table Example 1.

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));

 

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 ‘bato’);

 

Help and Show Commands

$ mysql –help | less
$ mysqld –help
$ mysqlshow –help | less
$ mysqldump –help | less
$ mysqlshow – show all databases.
$ mysqlshow db_name – all tables in particular database.
$ mysqlshow db_name BA* – all tables which start from BA letters.mysql> \?
mysql> use db_name;
mysql> show databases;
mysql> show databases like ‘ba%’
mysql> show tables;
mysql> describe table_name;
mysql> select user(), now(), version(), database();
+—————+———————+—————-+————+
| user()        | now()               | version()      | database() |
+—————+———————+—————-+————+
| ana@localhost | 2003-01-05 21:24:27 | 4.0.1-alpha-nt | test       |
+—————+———————+—————-+————+mysql> show tables from db_name
mysql> show tables from db_name like ‘__ab%’
mysql> show columns from table_name
mysql> show columns from table_name from db_name
mysql> show grants for user_name
mysql> show index from table_name
mysql> show index from table_name from db_name
mysql> show processlist
mysql> show status
mysql> show table status from db_name
mysql> show variables