Mega Code Archive

 

Categories / MySQL Tutorial / Table

 

Choose partial key in table creation

mysql> mysql> CREATE TABLE Employee (     ->   last_name VARCHAR(30) NOT NULL,     ->   KEY lastname_idx (last_name(3))     -> ); Query OK, 0 rows affected (0.03 sec) mysql> mysql> SHOW KEYS FROM Employee; +----------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | Table    | Non_unique | Key_name     | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | +----------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | Employee |          1 | lastname_idx |            1 | last_name   | A         |        NULL |        3 | NULL   |      | BTREE      |         | +----------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ 1 row in set (0.00 sec) mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.02 sec) mysql>