mysql的查询语句，where条件后面跟if语句

本文主要是介绍mysql的查询语句，where条件后面跟if语句，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

自己在写商城的时候碰到一个的感觉挺有意思的查询，记录下来，同时发布出来，希望可以帮到有需要的同学
where 条件后面跟if判断

where  1=1 
            AND (if( automobile_price IS NULL and  train_price IS NULL ,price >= #{command.minPrice,jdbcType=DECIMAL},price < 0)
            or if(automobile_price IS NULL and train_price IS NOT NULL,( train_price + price ) >= #{command.minPrice,jdbcType=DECIMAL},price < 0 )
            or if(automobile_price IS NOT NULL and train_price IS NULL,( automobile_price + price ) >= #{command.minPrice,jdbcType=DECIMAL} ,price < 0)
            or if(automobile_price IS NOT NULL and train_price IS NOT NULL,GREATEST( automobile_price + price, train_price + price ) >= #{command.minPrice,jdbcType=DECIMAL} ,price < 0 )
            )
            AND (IF(automobile_price IS NULL and train_price IS NULL,price <= #{command.maxPrice,jdbcType=DECIMAL},price < 0 )
            or if(automobile_price IS NULL and train_price IS NOT NULL,( train_price + price ) <= #{command.maxPrice,jdbcType=DECIMAL},price < 0)
            or if(automobile_price IS NOT NULL and train_price IS NULL,( automobile_price + price ) <= #{command.maxPrice,jdbcType=DECIMAL},price < 0)
            or if(automobile_price IS NOT NULL and train_price IS NOT NULL,LEAST( automobile_price + price, train_price + price ) <= #{command.maxPrice,jdbcType=DECIMAL},price < 0 )
            )
       

大体的意思就是 if(条件，条件为true执行，条件为false执行)

另外记录一些关键词 LEAST( automobile_price + price, train_price + price ) 取2者中最小的值
GREATEST( automobile_price + price, train_price + price ) 取2者中最大的值
ifnull(automobile_price,0) 如果值为null,则赋值0

这篇关于mysql的查询语句，where条件后面跟if语句的文章就介绍到这儿，希望我们推荐的文章对大家有所帮助，也希望大家多多支持为之网！