让我们首先创建一个表-
mysql> create table DemoTable ( Id int, Name varchar(50) );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable values(1001,'Robert'); mysql> insert into DemoTable values(1002,'Sam'); mysql> insert into DemoTable values(1003,'Tom');
使用select语句显示表中的所有记录-
mysql> select *from DemoTable;
这将产生以下输出-
+------+--------+ | Id | Name | +------+--------+ | 1001 | Robert | | 1002 | Sam | | 1003 | Tom | +------+--------+ 3 rows in set (0.00 sec)
以下是将特定单元格更新为MySQL中为空的查询-
mysql> update DemoTable set Name='' where Id=1003; Rows matched: 1 Changed: 1 Warnings: 0
让我们再次检查表记录-
mysql> select *from DemoTable;
这将产生以下输出-
+------+--------+ | Id | Name | +------+--------+ | 1001 | Robert | | 1002 | Sam | | 1003 | | +------+--------+ 3 rows in set (0.00 sec)