支不支持 if exists()？ - V2EX

Home Sign Up Sign In

› MySQL 5.5 Community Server

› MySQL 5.6 Community Server

› Percona Configuration Wizard

› XtraBackup 搭建主从复制

Great Sites on MySQL

› MySQL Performance Blog

› Severalnines

推荐管理工具

推荐书目

› MySQL Cookbook

MySQL 相关项目

参考文档

› http://mysql-python.sourceforge.net/MySQLdb.html

This topic created in 1922 days ago, the information mentioned may be changed or developed.

像这样的，在 mysql 如何写？
IF EXISTS(SELECT * FROM shares WHERE file_id='1' AND user_id='4') THEN
SELECT * FROM shares WHERE file_id='1' AND user_id='4'
ELSE
SELECT * FROM shares WHERE file_id='2' AND user_id='5'
END IF

1 replies • 2021-02-07 11:50:08 +08:00

1

ElmerZhang

Feb 7, 2021

SELECT * FROM shares WHERE ( file_id='1' AND user_id='4' ) OR (file_id='2' AND user_id='5') ORDER BY file_id ASC LIMIT 1;

About · Help · Advertise · Blog · API · FAQ · Solana · 5531 Online Highest 6679 ·

Select Language

创意工作者们的社区

World is powered by solitude

VERSION: 3.9.8.5 · 39ms · UTC 08:21 · PVG 16:21 · LAX 01:21 · JFK 04:21
♥ Do have faith in what you're doing.