MySQL TINYINT类型返回 <> 1或IS NULL记录
让我们首先创建一个表-
mysql> create table DemoTable -> ( -> EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY , -> EmployeeName varchar(20), -> isMarried tinyint -> );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(EmployeeName,isMarried) values('Chris',NULL);
mysql> insert into DemoTable(EmployeeName,isMarried) values('David',1);
mysql> insert into DemoTable(EmployeeName,isMarried) values('Mike',0);
mysql> insert into DemoTable(EmployeeName,isMarried) values('Sam',NULL);
mysql> insert into DemoTable(EmployeeName,isMarried) values('Bob',0);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-
+------------+--------------+-----------+ | EmployeeId | EmployeeName | isMarried | +------------+--------------+-----------+ | 1 | Chris | NULL | | 2 | David | 1 | | 3 | Mike | 0 | | 4 | Sam | NULL | | 5 | Bob | 0 | +------------+--------------+-----------+ 5 rows in set (0.00 sec)
这是显示记录<>1或ISNULL的查询-
mysql> select *from DemoTable where isMarried <> 1 or isMarried IS NULL;
这将产生以下输出-
+------------+--------------+-----------+ | EmployeeId | EmployeeName | isMarried | +------------+--------------+-----------+ | 1 | Chris | NULL | | 3 | Mike | 0 | | 4 | Sam | NULL | | 5 | Bob | 0 | +------------+--------------+-----------+ 4 rows in set (0.00 sec)