Browsing

SHOW DATABASES;
SHOW TABLES;
SHOW FIELDS FROM table / DESCRIBE table;
SHOW CREATE TABLE table;
SHOW PROCESSLIST;
KILL process_number;

Select - Join

    SELECT ... FROM t1 JOIN t2 ON t1.id1 = t2.id2 WHERE condition;
    SELECT ... FROM t1 LEFT JOIN t2 ON t1.id1 = t2.id2 WHERE condition;
    SELECT ... FROM t1 JOIN (t2 JOIN t3 ON ...) ON ...

Select

    SELECT * FROM table;
    SELECT * FROM table1, table2;
    SELECT field1, field2 FROM table1, table2;
    SELECT ... FROM ... WHERE condition
    SELECT ... FROM ... WHERE condition GROUP BY field;
    SELECT ... FROM ... WHERE condition GROUP BY field HAVING condition2;
    SELECT ... FROM ... WHERE condition ORDER BY field1, field2;
    SELECT ... FROM ... WHERE condition ORDER BY field1, field2 DESC;
    SELECT ... FROM ... WHERE condition LIMIT 10;
    SELECT DISTINCT field1 FROM ...
    SELECT DISTINCT field1, field2 FROM ...

Create / Open / Delete Database

    CREATE DATABASE DatabaseName;
    CREATE DATABASE DatabaseName CHARACTER SET utf8;
    USE DatabaseName;
    DROP DATABASE DatabaseName;
    ALTER DATABASE DatabaseName CHARACTER SET utf8;

Conditions

field1 = value1
    field1 <> value1
    field1 LIKE 'value _ %'
    field1 IS NULL
    field1 IS NOT NULL
    field1 IS IN (value1, value2)
    field1 IS NOT IN (value1, value2)
    condition1 AND condition2
    condition1 OR condition2

Backup Database to SQL File

mysqldump -u Username -p dbNameYouWant > databasename_backup.sql

Repair Tables After Unclean Shutdown

mysqlcheck --all-databases;
    mysqlcheck --all-databases --fast;

Update

UPDATE table1 SET field1=new_value1 WHERE condition;
    UPDATE table1, table2 SET field1=new_value1, field2=new_value2, ... WHERE
      table1.id1 = table2.id2 AND condition;

Create / Delete / Modify Table

CREATE TABLE table (field1 type1, field2 type2);
    CREATE TABLE table (field1 type1, field2 type2, INDEX (field));
    CREATE TABLE table (field1 type1, field2 type2, PRIMARY KEY (field1));
    CREATE TABLE table (field1 type1, field2 type2, PRIMARY KEY (field1,field2));

CREATE TABLE table1 (fk_field1 type1, field2 type2, ...,
    FOREIGN KEY (fk_field1) REFERENCES table2 (t2_fieldA))
      [ON UPDATE|ON DELETE] [CASCADE|SET NULL]

CREATE TABLE table1 (fk_field1 type1, fk_field2 type2, ...,
    FOREIGN KEY (fk_field1, fk_field2) REFERENCES table2 (t2_fieldA, t2_fieldB))

CREATE TABLE table IF NOT EXISTS;

CREATE TEMPORARY TABLE table;

DROP TABLE table;
    DROP TABLE IF EXISTS table;
    DROP TABLE table1, table2, ...

ALTER TABLE table MODIFY field1 type1
    ALTER TABLE table MODIFY field1 type1 NOT NULL ...
    ALTER TABLE table CHANGE old_name_field1 new_name_field1 type1
    ALTER TABLE table CHANGE old_name_field1 new_name_field1 type1 NOT NULL ...
    ALTER TABLE table ALTER field1 SET DEFAULT ...
    ALTER TABLE table ALTER field1 DROP DEFAULT
    ALTER TABLE table ADD new_name_field1 type1
    ALTER TABLE table ADD new_name_field1 type1 FIRST
    ALTER TABLE table ADD new_name_field1 type1 AFTER another_field
    ALTER TABLE table DROP field1

    ALTER TABLE table MODIFY field1 type1 FIRST
    ALTER TABLE table MODIFY field1 type1 AFTER another_field
    ALTER TABLE table CHANGE old_name_field1 new_name_field1 type1 FIRST
    ALTER TABLE table CHANGE old_name_field1 new_name_field1 type1 AFTER
      another_field  

Reset Root Password

    $ /etc/init.d/mysql stop
$ mysqld_safe --skip-grant-tables
$ mysql # on another terminal
mysql> UPDATE mysql.user SET password=PASSWORD('new_pass') WHERE user='root';
## Switch back to the mysqld_safe terminal and kill the process using Control + \
$ /etc/init.d/mysql start

Restore from backup SQL File

mysql -u Username -p dbNameYouWant < databasename_backup.sql;

Insert

INSERT INTO table1 (field1, field2) VALUES (value1, value2);

Delete

DELETE FROM table1 / TRUNCATE table1
    DELETE FROM table1 WHERE condition
    DELETE FROM table1, table2 WHERE table1.id1 =
      table2.id2 AND condition

Keys

CREATE TABLE table (..., PRIMARY KEY (field1, field2))
    CREATE TABLE table (..., FOREIGN KEY (field1, field2) REFERENCES table2
    (t2_field1, t2_field2))

Users and Privileges

CREATE USER 'user'@'localhost';
    GRANT ALL PRIVILEGES ON base.* TO 'user'@'localhost' IDENTIFIED BY 'password';
    GRANT SELECT, INSERT, DELETE ON base.* TO 'user'@'localhost' IDENTIFIED BY 'password';
    REVOKE ALL PRIVILEGES ON base.* FROM 'user'@'host'; -- one permission only
    REVOKE ALL PRIVILEGES, GRANT OPTION FROM 'user'@'host'; -- all permissions
    FLUSH PRIVILEGES;

    SET PASSWORD = PASSWORD('new_pass');
    SET PASSWORD FOR 'user'@'host' = PASSWORD('new_pass');
    SET PASSWORD = OLD_PASSWORD('new_pass'); 

DROP USER 'user'@'host';
    Host ‘%’ indicates any host.

Main Data Types

TINYINT (1o: -128 to +127)
    SMALLINT (2o: +-65 000)
    MEDIUMINT (3o: +-16 000 000)
    INT (4o: +- 2 000 000 000)
    BIGINT (8o: +-9.10^18)
    Precise interval: -(2^(8*N-1)) -> (2^8*N)-1
    ⚠ INT(2) = “2 digits displayed” – NOT “number with 2 digits max”
    
    FLOAT(M,D)
    DOUBLE(M,D)
    FLOAT(D=0->53)
    ⚠ 8,3 -> 12345,678 – NOT 12345678,123!
    
    TIME (HH:MM)
    YEAR (AAAA)
    DATE (AAAA-MM-JJ)
    DATETIME (AAAA-MM-JJ HH:MM; années 1000->9999)
    TIMESTAMP (like DATETIME, but 1970->2038, compatible with Unix)
    VARCHAR (single-line; explicit size)
    TEXT (multi-lines; max size=65535)
    BLOB (binary; max size=65535)
    Variants for TEXT&BLOB: TINY (max=255), MEDIUM (max=~16000), and LONG (max=4Go). Ex: VARCHAR(32), TINYTEXT, LONGBLOB, MEDIUMTEXT
    
    ENUM ('value1', 'value2', ...) -- (default NULL, or '' if NOT NULL)