How to: MySQL Delete Column

How do I delete a column from an existing MySQL table using UNIX / Windows / Linux mysql command line utility sql syntax?

You need to use the ALTER TABLE syntax to change the structure of an existing table. For example, you can add or delete columns, create or destroy indexes, change the type of existing columns, and much more with ALTER TABLE.

Step # 1: Login to mysql

Type the following command:
mysql -u user -p databasename

Step 2: Delete column

First see table description:
desc tableName
Use the following syntax at mysql>
ALTER TABLE tableName DROP columnName;
For example, see t1 table description, enter:

DESC t1;

desc t1;

Sample outputs:

+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| c1    | int(11)     | YES  |     | NULL    |       | 
| c2    | varchar(30) | YES  |     | NULL    |       | 
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.00 sec)

Delete column c2, enter:

ALTER TABLE t1 DROP c2;
DESC t1

ALTER TABLE t1 DROP c2;
desc t1

Sample outputs:

+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| c1    | int(11) | YES  |     | NULL    |       | 
+-------+---------+------+-----+---------+-------+
1 row in set (0.00 sec)

Posted by: SXI ADMIN

The author is the creator of SXI LLC and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.