Fix MySQL ERROR 1075 (42000): Incorrect table definition; there can be only one auto column and it must be defined as a key
To fix this error, you need to add PRIMARY KEY to auto_increment field. Let us now see how this error occurs −
Here, we are creating a table and it gives the same error −
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
To solve the above error, you need to add PRIMARY KEY with AUTO_INCREMENT. Let us first create a table −
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)
Insert some records in the table using insert command −
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)Display all records from the table using select statement :
mysql> select *from DemoTable;
This will produce the following output −
+-----------+--------------+------------+
| StudentId | StudentName | StudentAge |
+-----------+--------------+------------+
| 1 | Chris Brown | 19 |
| 2 | David Miller | 18 |
| 3 | John Doe | 20 |
+-----------+--------------+------------+
3 rows in set (0.00 sec)
Published on 07-Oct-2019 16:25:19
