在MySQL中仅返回具有字符串值的列的前15个字符
要仅返回字符串值中的前15个字符，请使用MySQLSUBSTR()函数。
让我们首先创建一个表-
create table DemoTable ( Title varchar(100) );
使用插入命令在表中插入一些记录-
insert into DemoTable values('Introduction to MySQL');
insert into DemoTable values('Introduction to Java');
insert into DemoTable values('C in Depth with data structure and algorithm');使用select语句显示表中的所有记录-
select *from DemoTable;
这将产生以下输出-
+----------------------------------------------+ | Title | +----------------------------------------------+ | Introduction to MySQL | | Introduction to Java | | C in Depth with data structure and algorithm | +----------------------------------------------+ 3 rows in set (0.00 sec)
现在让我们实现查询以仅获取前15个字符-
select substr(Title,1,15) from DemoTable;
这将产生以下输出-
+--------------------+ | substr(Title,1,15) | +--------------------+ | Introduction to | | Introduction to | | C in Depth with | +--------------------+ 3 rows in set (0.00 sec)