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, ...
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...
In TypeORM, you can order your results by multiple columns. The 2 examples below show you how to do that. The first example uses the find() method whilst the second one uses a query builder. In both of these examples, we will work with...
因为ORDER BY是在SELECT执行后执行,那么ORDER BY就可以使用SELECT字句中设置的别名。SQL语法SELECT [DISTINCT] * | 列 [AS] [别名] , 列 [AS] [别名],...FROM 表名称 [别名][WHERE 限定条件(s)][ORDER BY 排序字段 [ASC | DESC] [,排序字段 [ASC | DESC] ...]];...
通过执行计划,可以确认是用的文件排序,表确实也没有加额外的索引。所以我们可以确定这个SQL执行时是会找到limit要求的行后立马返回查询结果的。 不过就算它立马返回,为什么分页会不准呢? 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...
只使用order by, 不使用limit时候,查询的语句: SELECT * FROM test ORDER BY score ASC 1. 2. 查询结果: 下面我们按照 score 升序,每页3条数据,来获取数据。 下面的sql依次为第1页、第2页、第3页、第4页、第5页的数据,如下: 查询第1页的语句: ...
SQL ORDER BY is versatile. Use theORDER BYkeyword to sort results with a SELECT statement. You can sort over multiple columns, in both ascending and descending order. Table of contents Introduction to SQL ORDER BY SQL ORDER BY Two Columns ...
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....
For example, the following query shows all the tracks ordered by the album_id. Try sorting it by other columns. Can you modify it to be sorted by their name?SELECT * FROM tracks ORDER BY album_id;You can list multiple things to ORDER BY, which is useful in the case where there are...