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  • mysql函数之二:left,right,substring,substring_index MySQL截取字符串函数方法

    函数:

      1、从左开始截取字符串

      left(str, length)

      说明:left(被截取字段,截取长度)

      例:select left(content,200) as abstract from my_content_t

      2、从右开始截取字符串

      right(str, length)

      说明:right(被截取字段,截取长度)

      例:select right(content,200) as abstract from my_content_t

      3、截取字符串

      substring(str, pos)

      substring(str, pos, length)

      说明:substring(被截取字段,从第几位开始截取)

      substring(被截取字段,从第几位开始截取,截取长度)

      例:select substring(content,5) as abstract from my_content_t

      select substring(content,5,200) as abstract from my_content_t

      (注:如果位数是负数 如-5 则是从后倒数位数,到字符串结束或截取的长度)

      4、按关键字截取字符串

      substring_index(str,delim,count)

      说明:substring_index(被截取字段,关键字,关键字出现的次数)

      例:select substring_index(”blog.chinabyte.com”,”。”,2) as abstract from my_content_t

      结果:blog.chinabyte

      (注:如果关键字出现的次数是负数 如-2 则是从后倒数,到字符串结束)

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  • 原文地址:https://www.cnblogs.com/duanxz/p/3936714.html
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