在 WHERE 子句中使用 mysql concat()? [英] Using mysql concat() in WHERE clause?

问题描述

我想在我的表中搜索一列名字和一列姓氏.我目前接受一个字段中的搜索词并将其与两列进行比较，一次一个与

I would like to search my table having a column of first names and a column of last names. I currently accept a search term from a field and compare it against both columns, one at a time with

    select * from table where first_name like '%$search_term%' or 
    last_name like '%$search_term%';

这适用于单字搜索词，但结果集包括所有名字为Larry"的人.但是，如果有人输入名字，然后是空格，然后是姓氏，我想要更窄的搜索结果.我尝试了以下但没有成功.

This works fine with single word search terms but the result set includes everyone with the name "Larry". But if someone enters a first name then a space, then a last name, I want a narrower search result. I've tried the following without success.

    select * from table where first_name like '%$search_term%' or last_name 
    like '%$search_term%' or concat_ws(' ',first_name,last_name) 
    like '%$search_term%';

有什么建议吗?

我正在测试的名字是Larry Smith".数据库在first_name"列中存储Larry"，在last_name"列中存储Smith".数据干净，没有多余的空格，搜索词被左右修剪.

The name I'm testing with is "Larry Smith". The db stores "Larry" in the "first_name" column, and "Smith" in the "last_name" column. The data is clean, no extra spaces and the search term is trimmed left and right.

编辑 2: 今天早上我尝试了 Robert Gamble 的答案.他和我昨晚跑步的很相似.我无法解释，但今天早上它有效.我能想到的唯一区别是昨晚我将 concat 函数作为搜索查询的第三个或"段(在查看 first_name 和 last_name 之后)运行.今天早上，在浏览了上述内容以及地址和公司名称后，我将它作为最后一部分运行.

EDIT 2: I tried Robert Gamble's answer out this morning. His is very similar to what I was running last night. I can't explain it, but this morning it works. The only difference I can think of is that last night I ran the concat function as the third "or" segment of my search query (after looking through first_name and last_name). This morning I ran it as the last segment after looking through the above as well as addresses and business names.

在查询结束时运行 mysql 函数是否比在中间运行更好?

Does running a mysql function at the end of a query work better than in the middle?

推荐答案

你所拥有的应该有效，但可以简化为:

What you have should work but can be reduced to:

select * from table where concat_ws(' ',first_name,last_name) 
like '%$search_term%';

您能否提供一个不起作用的示例名称和搜索词?

Can you provide an example name and search term where this doesn't work?

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