DISTINCT和Using Temporary的关系 DISTINCT关键字和Using Temporary标志之间存在一定的关联。当我们在查询中使用DISTINCT关键字时,如果MySQL无法直接使用索引来完成查询,它就可能会创建一个临时表来处理数据。 下面是一个使用DISTINCT关键字和Using Temporary标志的示例: EXPLAIN SELECT
Using DISTINCT to Eliminate Duplicates Problem You want to know which values are present in a set of values, without listing duplicate values a bunch of times. Or you want … - Selection from MySQL Cookbook [Book]
实现"mysql DISTINCT Using temporary"的步骤 流程图 开始执行SQL查询使用DISTINCT关键字生成临时表返回查询结果结束 表格展示步骤 代码实现 步骤1:执行SQL查询 ```sql SELECT * FROM table_name; 1. 2. 该代码用于执行SQL查询,从名为table_name的表中选取所有的数据。 ### 步骤2:使用DISTINCT关键字 ```markdow...
Bug #32004 IN list select using DISTINCT Submitted: 31 Oct 2007 20:09Modified: 1 Dec 2007 10:17 Reporter: Bill McCaffrey Email Updates: Status: No Feedback Impact on me: None Category: MySQL Server: ParserSeverity: S1 (Critical) Version: 5.0.45-logOS: Linux Assigned to: CPU ...
Summary: in this tutorial, you will learn how to use MySQL DISTINCT clause with the SELECT statement to eliminate duplicate rows in a result set.Introduction to MySQL DISTINCT clause#When querying data from a table, you may get duplicate rows. In order to remove these duplicate rows, you ...
Re: How to query this using distinct? Bob Field June 27, 2006 08:54AM Sorry, you can't reply to this topic. It has been closed.Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent...
For example, these statements are distinct from each other: SELECT first_name, last_name FROM customer WHERE customer_id = 1; select first_name, last_name from customer where customer_id = 99; SELECT first_name, last_name FROM customer WHERE customer_id = 143; But all of them have ...
The default output format is different (more concise) when you runmysqlin batch mode than when you use it interactively. For example, the output ofSELECT DISTINCT species FROM petlooks like this whenmysqlis run interactively: +---+ | species | +---+ | bird | | cat | | dog | | ha...
信息种类:Using filesort 、Using temporary 、Using index 、Using where 、Using join buffer 、impossible where 、select tables optimized away 、distinct Using filesort(需要优化) 说明mysql会对数据使用一个外部的索引排序,而不是按照表内的索引顺序进行读取。MySQL中无法利用索引完成的排序操作称为"文件排序" ...
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