MySQL SUBSTRING_INDEX() 函数

返回字符串中指定数量的分隔符出现之前的子字符串：

SELECT SUBSTRING_INDEX("www.91xjr.com", ".", 1);

定义和用法

SUBSTRING_INDEX() 函数返回指定数量的分隔符出现之前的字符串的子字符串。

SUBSTRING_INDEX( string, delimiter, number)

Parameter	Description
string	Required. The original string
delimiter	Required. The delimiter to search for
number	Required. The number of times to search for the delimiter. Can be both a positive or negative number. If it is a positive number, this function returns all to the left of the delimiter. If it is a negative number, this function returns all to the right of the delimiter.

工作于：	从 MySQL 4.0 开始