修复 MySQL 错误 1406:Data too long for column" but it shouldn't be?
mysqlmysqli database
如果您尝试设置高于允许限制的数据，则可能会发生此错误。例如，您无法将字符串存储在 bit 类型的列中，因为 varchar 或字符串占用的大小高于 bit 数据类型。
您需要对 bit 类型列使用以下语法:
anyBitColumnName= b ‘1’ OR anyBitColumnName= b ‘0’
为了理解上述语法，让我们创建一个表。创建表的查询如下:
mysql> create table IncasesensitiveDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Name varchar(10), -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.70 sec)
使用 insert 命令在表中插入一些记录。插入记录的查询如下:
mysql> insert into ErrorDemo(Name,isStudent) values('John',1);
Query OK, 1 row affected (0.18 sec)
mysql> insert into ErrorDemo(Name,isStudent) values('Sam',0);
Query OK, 1 row affected (0.21 sec)
mysql> insert into ErrorDemo(Name,isStudent) values('Mike',0);
Query OK, 1 row affected (0.16 sec)
mysql> insert into ErrorDemo(Name,isStudent) values('Larry',1);
Query OK, 1 row affected (0.23 sec)
mysql> insert into ErrorDemo(Name,isStudent) values('Carol',1);
Query OK, 1 row affected (0.11 sec)
mysql> insert into ErrorDemo(Name,isStudent) values('Robert',0);
Query OK, 1 row affected (0.17 sec)
mysql> insert into ErrorDemo(Name,isStudent) values('James',1);
Query OK, 1 row affected (0.18 sec)
mysql> insert into ErrorDemo(Name,isStudent) values('Bob',1);
Query OK, 1 row affected (0.19 sec)
mysql> insert into ErrorDemo(Name,isStudent) values('David',1);
Query OK, 1 row affected (0.15 sec)
mysql> insert into ErrorDemo(Name,isStudent) values('Ricky',0);
Query OK, 1 row affected (0.17 sec)
使用 select 语句显示表中的所有记录。查询如下:
mysql> select *from ErrorDemo;
输出结果如下:
+----+--------+-----------+ | Id | Name | isStudent | +----+--------+-----------+ | 1 | John | | | 2 | Sam | | | 3 | Mike | | | 4 | Larry | | | 5 | Carol | | | 6 | Robert | | | 7 | James | | | 8 | Bob | | | 9 | David | | | 10 | Ricky | | +----+--------+-----------+ 10 rows in set (0.00 sec)
实际示例输出快照如下:
错误如下，如上所述。它在以下查询中生成:
mysql> update ErrorDemo set isStudent='1' where Id=9; ERROR 1406 (22001): Data too long for column 'isStudent' at row 1
为了避免上述错误，需要在‘1’前加上前缀b。现在查询如下:
mysql> update ErrorDemo set isStudent=b'1' where Id=9; Query OK, 0 rows affected (0.00 sec) Rows matched: 1 Changed: 0 Warnings: 0
再次使用 select 语句检查表记录。查询如下:
mysql> select *from ErrorDemo;
输出结果如下:
+----+--------+-----------+ | Id | Name | isStudent | +----+--------+-----------+ | 1 | John | | | 2 | Sam | | | 3 | Mike | | | 4 | Larry | | | 5 | Carol | | | 6 | Robert | | | 7 | James | | | 8 | Bob | | | 9 | David | | | 10 | Ricky | | +----+--------+-----------+ 10 rows in set (0.00 sec)
实际示例输出快照如下:
查看 is Student 列。
现在我们将用值 0 更新相同的 id。这将给出一个具有相应 Id 的空白值。查询如下:
mysql> update ErrorDemo set Name='Maxwell', isStudent=b'0' where Id=9; Query OK, 1 row affected (0.16 sec) Rows matched: 1 Changed: 1 Warnings: 0
检查上面更新的特定行的记录。这是 ID 9。现在行已更新为记录 ID 9。查询如下:
mysql> select *from ErrorDemo where Id=9;
输出结果如下:
+----+---------+-----------+ | Id | Name | isStudent | +----+---------+-----------+ | 9 | Maxwell | | +----+---------+-----------+ 1 row in set (0.00 sec)
