MySQL命令行删除表中的一个字段
先看看删除之前的表结构:
mysql>select*fromtest;
+------+--------+----------------------------------+------------+------------+------------+------------+
|t_id|t_name|t_password |t_birth |birth |birth1 |birth2 |
+------+--------+----------------------------------+------------+------------+------------+------------+
| 1|name1 |12345678901234567890123456789012|NULL |1990-01-01|0000-00-00|2013-01-01|
| 2|name2 |12345678901234567890123456789012|2013-01-01|NULL |0000-00-00|2013-01-01|
+------+--------+----------------------------------+------------+------------+------------+------------+
2rowsinset(0.00sec)
执行删除命令,使用drop关键字。
基本的语法为:altertable<表名>dropcolumn<字段名>;
具体的命令如下:
mysql>altertabletestdropcolumnbirth1;
QueryOK,0rowsaffected(0.13sec)
Records:0 Duplicates:0 Warnings:0
看看删除后的结果,是不是已经没有birth1字段了?
mysql>select*fromtest;
+------+--------+----------------------------------+------------+------------+------------+
|t_id|t_name|t_password |t_birth |birth |birth2 |
+------+--------+----------------------------------+------------+------------+------------+
| 1|name1 |12345678901234567890123456789012|NULL |1990-01-01|2013-01-01|
| 2|name2 |12345678901234567890123456789012|2013-01-01|NULL |2013-01-01|
+------+--------+----------------------------------+------------+------------+------------+
2rowsinset(0.00sec)
关于MySQL中根据生日计算年龄的SQL语句日期函数,本文就介绍这么多,希望对大家有所帮助,谢谢!