修复 MySQL 错误 1075 (42000):Incorrect table definition; there can be only one auto column and it must be defined as a key
mysqlmysqli database
要修复此错误，您需要将 PRIMARY KEY 添加到 auto_increment 字段。现在让我们看看此错误是如何发生的 −
在这里，我们正在创建一个表，它给出了相同的错误 −
mysql> create table DemoTable ( StudentId int NOT NULL AUTO_INCREMENT, StudentName varchar(40), StudentAge int ); ERROR 1075 (42000) : Incorrect table definition; there can be only one auto column and it must be defined as a key
要解决上述错误，您需要添加带有 AUTO_INCREMENT 的 PRIMARY KEY。让我们首先创建一个表 −
mysql> create table DemoTable ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentName varchar(40), StudentAge int ); Query OK, 0 rows affected (1.01 sec)
使用 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable(StudentName,StudentAge) values('Chris Brown',19);
Query OK, 1 row affected (0.30 sec)
mysql> insert into DemoTable(StudentName,StudentAge) values('David Miller',18);
Query OK, 1 row affected (0.20 sec)
mysql> insert into DemoTable(StudentName,StudentAge) values('John Doe',20);
Query OK, 1 row affected (0.11 sec)
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 −
+-----------+--------------+------------+ | StudentId | StudentName | StudentAge | +-----------+--------------+------------+ | 1 | Chris Brown | 19 | | 2 | David Miller | 18 | | 3 | John Doe | 20 | +-----------+--------------+------------+ 3 rows in set (0.00 sec)
