SHOW DATABASES
SHOW TABLES
SHOW FIELDS FROM table / DESCRIBE table
SHOW CREATE TABLE table
SHOW PROCESSLIST
SHOW GLOBAL STATUS
KILL process_number
CREATE DATABASE dbname
CREATE DATABASE dbname CHARACTER SET utf8
CREATE DATABASE dbname COLLATE utf8_general_ci
DROP DATABASE dbname
ALTER DATABASE dbname CHARACTER SET utf8
host ‘%’ indicates any host
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
SET PASSWORD = PASSWORD('new_pass')
SET PASSWORD FOR 'user'@'host' = PASSWORD('new_pass')
SET PASSWORD = OLD_PASSWORD('new_pass')
DROP USER 'user'@'host'
FLUSH PRIVILEGES
SELECT * FROM table
SELECT * FROM table1, table2, ...
SELECT field1, field2, ... FROM table1, table2, ...
SELECT ... FROM ... WHERE condition
SELECT ... FROM ... WHERE condition GROUPBY field
SELECT ... FROM ... WHERE condition GROUPBY 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 ...
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
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 ...
INSERT INTO table1 (field1, field2, ...) VALUES (value1, value2, ...)
INSERT INTO table1 SET field1=value1, field2=value2
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
DELETE FROM table1 / TRUNCATE table1
DELETE FROM table1 WHERE condition
DELETE FROM table1, table2 FROM table1, table2 WHERE table1.id1 =
table2.id2 AND condition
CREATE TABLE table (..., PRIMARY KEY (field1, field2))
CREATE TABLE table (..., FOREIGN KEY (field1, field2) REFERENCES table2 (t2_field1, t2_field2))
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 ADD INDEX (field);
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
TINYINT (1o: -217+128)
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)
FLOAT(D=0->53)
DOUBLE(M,D)
DECIMAL(M,D)
/!\ 8,3 -> 12345,678 -- NOT 12345678,123!
TIME (HH:MM)
YEAR (AAAA)
DATE (AAAA-MM-JJ)
DATETIME (AAAA-MM-JJ HH:MM; years 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) LONG (max=4Go)
Ex: VARCHAR(32), TINYTEXT, LONGBLOB, MEDIUMTEXT
ENUM ('value1', 'value2', ...) -- (default NULL, or '' if NOT NULL)
mysqldump -u Username -p DatabaseName > databasename_backup.sql
mysqldump -u Username -p --all_databases | gzip -c > 'date "+%Y-%m-%d"'.bz2
# file encoding definition
file --mime-encoding dump.sql
# convert from latin1 to utf8 encoding
mysqldump --add-drop-table -uroot -p dbname | replace CHARSET=latin1 CHARSET=utf8 | iconv -f latin1 -t utf8 | mysql -uroot -p dbname
mysql -u Username -p DatabaseName < databasename_backup.sql
mysql -u Username -p DatabaseName < databasename_backup_`date +\%Y-\%m-\%d_\%H`.sql
mysql -u Username -p --default-character-set=utf8 database
$ /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';
mysql> FLUSH PRIVILEGES;
mysql> \q
## Switch back to the mysqld_safe terminal and kill the process using Control + \
$ /etc/init.d/mysql start
mysqlcheck --all-databases
mysqlcheck --all-databases --fast
mysqlcheck --repair --analyze --optimize --all-databases --auto-repair -u root -pSECRET