MySQL 如何在WHERE子句中使用LOCATE()函数
当我们在MySQL WHERE子句中使用LOCATE()函数时,需要在第一个参数中提供子字符串,在第二个参数中提供表的列名称以及比较运算符。以下是使用“Student”表演示的示例:-
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示例
假设我们在’Student’表中有以下值-
mysql> Select * from Student;
+------+---------+---------+-----------+
| Id | Name | Address | Subject |
+------+---------+---------+-----------+
| 1 | Gaurav | Delhi | Computers |
| 2 | Aarav | Mumbai | History |
| 15 | Harshit | Delhi | Commerce |
| 20 | Gaurav | Jaipur | Computers |
| 21 | Yashraj | NULL | Math |
+------+---------+---------+-----------+
5 rows in set (0.02 sec)
现在,以下查询显示了我们如何将LOCATE()函数与WHERE子句一起使用
mysql> Select Name, LOCATE('av',name)As Result from student where LOCATE('av',Name) > 0;
+--------+--------+
| Name | Result |
+--------+--------+
| Gaurav | 5 |
| Aarav | 4 |
| Gaurav | 5 |
+--------+--------+
3 rows in set (0.00 sec)
mysql> select name, LOCATE('av',name)As Result from student where LOCATE('av',Name)=0 ;
+---------+--------+
| name | Result |
+---------+--------+
| Harshit | 0 |
| Yashraj | 0 |
+---------+--------+
2 rows in set (0.00 sec)