Mysql drop (remove) unique key

To remove a mysql unique key, aka index it first needs to be checked.

How to check mysql unique indexes existing on a table:

Code:

mysql> SHOW INDEXES FROM my_table;  
+----------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table    | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+----------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| my_table |          0 | id       |            1 | id          | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
+----------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+

Drop unique key (DROP INDEX `id` on my_table;):

Code:

mysql> DROP INDEX `id` on my_table;
Query OK, 0 rows affected (0.29 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> SHOW INDEXES FROM my_table;               
Empty set (0.00 sec)

Please make sure you have backups before running any drop/truncate commands in mysql.