使用INSERT语句时是否需要在MySQL中插入auto_increment列值?
不,没有必要插入auto_increment列值,因为它从1开始并自行插入。这是因为我们将其设置为自动增量。让我们首先创建一个表-
mysql> create table DemoTable ( EmployeeId int NOT NULL AUTO_INCREMENT, EmployeeName varchar(30), EmployeeSalary int, PRIMARY KEY(EmployeeId) );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(EmployeeName,EmployeeSalary) values('Chris',56789); mysql> insert into DemoTable(EmployeeName,EmployeeSalary) values('David',78909); mysql> insert into DemoTable(EmployeeName,EmployeeSalary) values('Mike',100056); mysql> insert into DemoTable(EmployeeName,EmployeeSalary) values('Bob',150000);
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。在这里,您可以看到id值是自己添加的,因为我们将其设置为auto_increment-
+------------+--------------+----------------+ | EmployeeId | EmployeeName | EmployeeSalary | +------------+--------------+----------------+ | 1 | Chris | 56789 | | 2 | David | 78909 | | 3 | Mike | 100056 | | 4 | Bob | 150000 | +------------+--------------+----------------+ 4 rows in set (0.00 sec)