MySQL 如何添加重复的varchar值而不显示错误

为此，让我们先看一个例子并创建一个表 −

mysql> create table DemoTable1409
   -> (
   -> FirstName varchar(20),
   -> UNIQUE KEY UN_FirstName(FirstName)
   -> );
Query OK, 0 rows affected (0.79 sec)

以下是添加重复varchar的查询−

mysql> alter table DemoTable1409 drop index  UN_FirstName;
Query OK, 0 rows affected (0.40 sec)
Records: 0  Duplicates: 0  Warnings: 0

使用insert语句向表中插入一些记录−

mysql> insert into DemoTable1409 values('Chris');
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable1409 values('Chris');
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable1409 values('David');
Query OK, 1 row affected (0.09 sec)

使用select语句从表中显示所有记录−

mysql> select * from DemoTable1409;

这将产生以下输出−

+-----------+
| FirstName |
+-----------+
| Chris     |
| Chris     |
| David     |
+-----------+
3 rows in set (0.00 sec)

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