在 UPDATE 查询的 SET 部分中反引号不起作用(对于 MySQL)的原因是什么?
反引号在以下语法中正确编写时可以工作 −
update `yourTableName` set `yourTableName`.`yourColumnName`='yourNewValue' where yourCondition;
我们先创建一个 −
mysql> create table `DemoTable_1401` -> ( -> Name varchar(20) -> ); Query OK, 0 rows affected (0.52 sec)
使用 insert 在表中插入一些记录 −
mysql> insert into `DemoTable_1401` values('Chris');
Query OK, 1 row affected (0.16 sec)
mysql> insert into `DemoTable_1401` values('David');
Query OK, 1 row affected (0.10 sec)
mysql> insert into `DemoTable_1401` values('Bob');
Query OK, 1 row affected (0.12 sec)使用 select 从表中显示所有记录 −
mysql> select * from `DemoTable_1401`;
这将产生以下输出 −
+-------+ | Name | +-------+ | Chris | | David | | Bob | +-------+ 3 rows in set (0.00 sec)
以下是对反引号起作用的查询 −
mysql> update `DemoTable_1401` set `DemoTable_1401`.`Name`='Adam' where `Name`='David'; Query OK, 1 row affected (0.15 sec) Rows matched: 1 Changed: 1 Warnings: 0
让我们再次检查表记录 −
mysql> select * from `DemoTable_1401`;
这将产生以下输出 −
+-------+ | Name | +-------+ | Chris | | Adam | | Bob | +-------+ 3 rows in set (0.00 sec)
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