在 alpha 字符上匹配两个 mysql cols(忽略同一字段中的数字) [英] Match two mysql cols on alpha chars (ignoring numbers in same field)

问题描述

我想知道您是否知道我可以过滤 mysql 查询以仅显示特定字段中的alpha"字符的方法

I was wondering if you know of a way I could filter a mysql query to only show the ‘alpha’ characters from a specific field

所以就像

SELECT col1, col2, **alpha_chars_only(col3)** FROM table 

我不想只更新选择.

我一直在研究一些正则表达式，但运气不佳，大部分结果都是搜索只包含alpha"字符的字段.

I have been looking at some regex but without much luck most of what turned up was searching for fields that only contain ‘alpha’ chars.

在一个被淡化的背景下......我有包含 abc 的 col1 和包含 abc123 的 col 2，我只想在 alpha 字符上匹配它们.可以有任意数量的字母或数字.

In a much watered down context... I have col1 which contains abc and col two contains abc123 and I want to match them on alpha chars only. There can be any number of letters or numbers.

非常欢迎任何帮助

推荐答案

您可能需要为此编写自定义函数.如果你想在 MySQL 中这样做，你可以创建一个这样的存储函数:

You probably need to write a custom function for this. If you want to do it in MySQL, you could create a stored function like this:

DELIMITER $$

drop function if exists alpha_chars_only $$

create function alpha_chars_only (p_string text) returns text
begin
  declare v_return_val text default '';
  declare v_iter int unsigned default 1;
  declare v_length int unsigned default 0;
  declare v_char char(1) default null;

  set v_length = char_length(p_string);

  while (v_iter <= v_length)
  do
    set v_char = substring(p_string,v_iter,1);
    if (v_char REGEXP '[a-z]')
    then
      set v_return_val = concat(v_return_val,v_char);
    end if;
    set v_iter = v_iter + 1;
  end while;

  return v_return_val;
end $$

DELIMITER ;

这篇关于在 alpha 字符上匹配两个 mysql cols(忽略同一字段中的数字)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！