在MySQL中用分隔符分隔字符串的左侧部分吗？
您可以使用MySQL的substring_index()函数分割字符串的左侧部分。语法如下-
SELECT yourColumnName1,.....N,SUBSTRING_INDEX(yourColumnName,’yourSeperatorSymbol’,1) as anyVariableName from yourTableName;
值1表示您可以左移字符串的一部分。为了检查以上语法，让我们创建一个表。创建表的查询如下-
create table LeftStringDemo -> ( -> Id int, -> Words varchar(100) -> );
使用insert命令在表中插入一些记录。查询如下-
insert into LeftStringDemo values(1,'MySQL==6789'); insert into LeftStringDemo values(2,'Java==Object Oriented'); insert into LeftStringDemo values(3,'C Language==Procedural Programming'); insert into LeftStringDemo values(4,'PL/SQL==Structured Programming');
使用select语句显示表中的所有记录。查询如下-
select *from LeftStringDemo;
以下是输出
+------+------------------------------------+ | Id | Words | +------+------------------------------------+ | 1 | MySQL==6789 | | 2 | Java==Object Oriented | | 3 | C Language==Procedural Programming | | 4 | PL/SQL==Structured Programming | +------+------------------------------------+ 4 rows in set (0.00 sec)
这是在分隔符字符串'=='的基础上获取字符串列'Words'左侧部分的查询
select Id, substring_index(Words, '==', 1) as OnlyLefthandsideValue from LeftStringDemo;
以下是输出
+------+-----------------------+ | Id | OnlyLefthandsideValue | +------+-----------------------+ | 1 | MySQL | | 2 | Java | | 3 | C Language | | 4 | PL/SQL | +------+-----------------------+ 4 rows in set (0.00 sec)