Community Learn Tools Library Leisure
search
English
Home > Backend Development > PHP Tutorial > 在写php语句中sql的写法有些混

在写php语句中sql的写法有些混

WBOY
Release： 2016-06-13 12:19:50
Original
841 people have browsed it

在写php语句中sql的写法有点混
即where和having是否可以通用
------解决思路----------------------
where 是删选数据表的条件
having 是删选结果集的条件

经 where 删选后，结果集就可能会很小
having 只是再做一次筛选以挑出所需数据

Related labels：
nbsp php sql where
source：php.cn
Previous article：IE7中,Javascript使用[]目录字符串，失败，为何呢 Next article：PHP类的有关问题
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Latest Articles by Author
Latest Issues
function_exists() cannot determine the custom function Function test () {return true;} if (function_exists ('test')) {echo "test is function...
From 2024-04-29 11:01:01
0
2
1429
There is no output in the parent window document.onclick = function(){ window.opener.document.write('I am the output of the child ...
From 2024-04-18 23:52:34
0
1
1284
PX automatic conversion to REM error  <style>html {   font-size: calc(100vw / 3.75);      }...
From 2024-04-16 09:34:16
0
0
4687
Related Topics
More>
Popular Recommendations
Popular Tutorials
More>
Related Tutorials
Popular Recommendations
Latest courses
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template