What is the sql statement to delete a field?
The sql statement to delete a field is "ALTER TABLE", and the specific syntax format is "ALTER TABLE
DROP
;"; among them, the "field name" designation needs to be from the table The name of the deleted field.
The operating environment of this tutorial: windows7 system, mysql version 5.8, Dell G3 computer.
Deleting a field
Deleting a field is to remove a field in the data table from the table. The syntax format is as follows:
ALTER TABLE <表名> DROP <字段名>；Copy after loginAmong them, "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 (0.53 sec) Records: 0 Duplicates: 0 Warnings: 0 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 | | | deptId | int(11) | YES | | NULL | | | salary | float | YES | | NULL | | +--------+-------------+------+-----+---------+-------+ 5 rows in set (0.00 sec)Copy after loginFor more programming-related knowledge, please visit: Programming Video! !
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