Shulou(Shulou.com)05/31 Report--

This article is about how to write sql statements that delete fields in the database. The editor thinks it is very practical, so share it with you as a reference and follow the editor to have a look.

The sql statement to delete a field is "ALTER TABLE" with the syntax format "ALTER TABLE DROP;", where Field name specifies the name of the field to be deleted from the table.

Delete a field

Deleting a field removes a field from the data table in the following syntax format:

ALTER TABLE DROP

Where Field name refers to the name of the field that needs to be deleted from the table.

Example:

Mysql > DESC tb_emp1 +-+-+ | Field | Type | Null | Key | Default | Extra | + -+ | col1 | int (11) | YES | | NULL | id | int (11) | YES | | NULL | | name | varchar (30) | YES | | NULL | | col2 | int (11) | YES | | NULL | deptId | int (11) | YES | NULL | | salary | float | YES | | | NULL | | +-+-+ 6 rows in set (0.00 sec) mysql > ALTER TABLE tb_emp1-> DROP col2 | Query OK, 0 rows affected (.53 sec) Records: 0 Duplicates: 0 Warnings: 0mysql > DESC tb_emp1 +-+-+ | Field | Type | Null | Key | Default | Extra | + -+ | col1 | int (11) | YES | | NULL | id | int (11) | YES | | NULL | | name | varchar (30) | YES | | NULL | | deptId | int (11) | YES | | NULL | salary | float | YES | | NULL | | +-+-- | -+ 5 rows in set (0.00 sec) Thank you for your reading! This is the end of the article on "how to write the sql statement for deleting fields in the database". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, you can share it out for more people to see!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.