MySQL/CheatSheet
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< MySQL
Contents |
[edit] Query
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 ...
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 ...
conditionals:
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
[edit] Data Manipulation
INSERT INTO table1 (field1, field2, ...) VALUES (value1, value2, ...)
DELETE FROM table1 / TRUNCATE table1 DELETE FROM table1 WHERE condition -- join: DELETE FROM table1, table2 WHERE table1.id1 = table2.id2 AND condition
UPDATE table1 SET field1=new_value1 WHERE condition -- join: UPDATE table1, table2 SET field1=new_value1, field2=new_value2, ... WHERE table1.id1 = table2.id2 AND condition
[edit] Browsing
SHOW DATABASES SHOW TABLES SHOW FIELDS FROM table / DESCRIBE table SHOW CREATE TABLE table SHOW PROCESSLIST KILL process_number
[edit] Create / delete database
CREATE DATABASE mabase CREATE DATABASE mabase CHARACTER SET utf8 DROP DATABASE mabase
ALTER DATABASE mabase CHARACTER SET utf8
[edit] 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 ADD INDEX (field); ALTER TABLE table ADD PRIMARY KEY (field);
-- Change field order: 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
ALTER TABLE old_name RENAME new_name;
[edit] Keys
CREATE TABLE table (..., PRIMARY KEY (field1, field2)) CREATE TABLE table (..., FOREIGN KEY (field1, field2) REFERENCES table2 (t2_field1, t2_field2)) ALTER TABLE table ADD PRIMARY KEY (field);
[edit] Privileges
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'
[edit] Main data types
TINYINT (1o: -127+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) 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) LONG (max=4Go) Ex: VARCHAR(32), TINYTEXT, LONGBLOB, MEDIUMTEXT
ENUM ('value1', 'value2', ...) -- (default NULL, or '' if NOT NULL)
[edit] Forgot root password?
$ /etc/init.d/mysql stop
$ mysqld_safe --skip-grant-tables
$ mysql # on another terminal
mysql> UPDATE mysql.user SET password=PASSWORD('nouveau') WHERE user='root';
## Kill mysqld_safe from the terminal, using Control + \
$ /etc/init.d/mysql start
[edit] Repair tables after unclean shutdown
mysqlcheck --all-databases mysqlcheck --all-databases --fast
