二、“order by”引发的乱序 经过一番排查,发现罪魁祸首其实是order by。当使用order by的字段存在多行相同值时,就会导致上面出现的乱序问题,这里我们来看下官方的解释[1]: ❝If multiple rows have identical values in theORDER BYcolumns, the server is free to return those rows in any order, ...
ORDER BY 排序列存在相同值时返回顺序是不固定的 If multiple rows have identical values in the ORDER BY columns, the server is free to return those rows in any order, and may do so differently depending on the overall execution plan. In other words, the sort order of those rows is nondeter...
If multiple rows have identical values in theORDER BYcolumns, the server is free to return those rows in any order, and may do so differently depending on the overall execution plan. In other words, the sort order of those rows is nondeterministic with respect to the nonordered columns. 上...
productsorderhas 旅行图: MySQL两种条件下排序 参考资料: [MySQL ORDER BY]( [MySQL ORDER BY multiple columns]( 以上是关于MySQL两种条件下排序的科普文章,希望对你有所帮助。
If multiple rows have identical values in the ORDER BY columns, the server is free to return those rows in any order, and may do so differently depending on the overall execution plan. In other words, the sort order of those rows is nondeterministic with respect to the nonordered columns....
If multiple rows have identical values in theORDER BYcolumns, the server is free to return those rows in any order, and may do so differently depending on the overall execution plan. In other words, the sort order of those rows is nondeterministic with respect to the nonordered columns. ...
次优解是对order by后面的category 加索引(为什么是次优解?看完本文你将会有答案); 下面课代表将还原一下这 3 条结论的产出过程。 1. 最优解 MySQL 文档 8.2.1.19 LIMIT Query Optimization 中对此场景有如下描述: If multiple rows have identical values in the ORDER BY columns, the server is free to...
Bug #47280strange results from count(*) with order by multiple columns without where/group Submitted:11 Sep 2009 18:32Modified:18 Dec 2009 13:21 Reporter:Shane Bester(Platinum Quality Contributor)Email Updates: Status:ClosedImpact on me: ...
If multiple rows have identical values in the ORDER BY columns, the server is free to return those rows in any order, and may do so differently depending on the overall execution plan. In other words, the sort order of those rows is nondeterministic with respect to the nonordered columns....
官方文档里面做了如下说明: If multiple rows have identical values in the ORDER BY columns, the server is free to return those rows in any order, and may do so differently depending on the overall execution plan. In other words, the sort order of those rows is nondeterministic with respect ...