按MySQL中的第一个字符过滤列值
您可以从MySQL使用LEFT()。让我们首先创建一个-
create table DemoTable1428 -> ( -> EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> EmployeeName varchar(20) -> );
使用insert在表中插入一些记录-
insert into DemoTable1428(EmployeeName) values('Chris Brown');
insert into DemoTable1428(EmployeeName) values('Bob Brown');
insert into DemoTable1428(EmployeeName) values('John Smith');
insert into DemoTable1428(EmployeeName) values('David Miller');
insert into DemoTable1428(EmployeeName) values('John Doe');
insert into DemoTable1428(EmployeeName) values('Carol Johnson');使用选择显示表中的所有记录-
select * from DemoTable1428;
这将产生以下输出-
+------------+---------------+ | EmployeeId | EmployeeName | +------------+---------------+ | 1 | Chris Brown | | 2 | Bob Brown | | 3 | John Smith | | 4 | David Miller | | 5 | John Doe | | 6 | Carol Johnson | +------------+---------------+ 6 rows in set (0.00 sec)
以下是按第一个字符过滤列值的查询-
select * from DemoTable1428 where left(EmployeeName,1)='J';
这将产生以下输出-
+------------+--------------+ | EmployeeId | EmployeeName | +------------+--------------+ | 3 | John Smith | | 5 | John Doe | +------------+--------------+ 2 rows in set (0.00 sec)