Order by multiple OR 是一个用于MySQL查询语句的排序操作。它允许按照多个字段进行排序,并且使用OR逻辑进行连接。 在MySQL中,使用"Order by"关键字可以对查询结果进行排序。通常情况下,我们可以指定一个字段进行排序,例如: 代码语言:txt 复制 SELECT * FROM table_name ORDER BY column_name; 然而,在某些情况下,...
I have a query that I would like to display in a specific order. Here is the query. SELECT * FROM (SELECT * FROM debtors WHERE ID LIKE + "John%" or shortName LIKE + "John%" ORDER BY shortName) as a UNION ALL SELECT * FROM (SELECT * FROM debtors WHERE ID LIKE + ("%...
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 ...
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. ...
但是真正测试一下才发现这样效率非常低。一个15万余条的库,查询5条数据,居然要8秒以上。查看官方手册,也说rand()放在ORDER BY 子句中会被执行多次,自然效率及很低。 You cannot use a column with RAND() values in an ORDER BY clause, because ORDER BY would evaluate the column multiple times. ...
这种行为的一种表现是带有和不带有 LIMIT 的 ORDER BY 查询可能会以不同的顺序返回行,如本节后面所述。 原文: 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...
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 the ORDER BY columns, the server is free to return ...
Written By Posted Optimizing Multiple ORDER BYs 11429 Sep Si June 25, 2009 07:50PM Re: Optimizing Multiple ORDER BYs 3599 Rick James June 27, 2009 12:28AM Sorry, you can't reply to this topic. It has been closed. Content reproduced on this site is the property of the respective copyri...