MySQL不支持INTERSECT和MINUS及其替代方法

各位用户为了找寻关于MySQL不支持INTERSECT和MINUS及其替代方法的资料费劲了很多周折。这里教程网为您整理了关于MySQL不支持INTERSECT和MINUS及其替代方法的相关资料，仅供查阅，以下为您介绍关于MySQL不支持INTERSECT和MINUS及其替代方法的详细内容

Doing INTERSECT and MINUS in MySQL Doing an INTERSECT An INTERSECT is simply an inner join where we compare the tuples of one table with those of the other, and select those that appear in both while weeding out duplicates. So

代码如下:

SELECT member_id, name FROM a INTERSECT SELECT member_id, name FROM b

can simply be rewritten to

代码如下:

SELECT a.member_id, a.name FROM a INNER JOIN b USING (member_id, name)

Performing a MINUS To transform the statement

代码如下:

SELECT member_id, name FROM a MINUS SELECT member_id, name FROM b

into something that MySQL can process, we can utilize subqueries (available from MySQL 4.1 onward). The easy-to-understand transformation is:

代码如下:

SELECT DISTINCT member_id, name FROM a WHERE (member_id, name) NOT IN (SELECT member_id, name FROM table2);

Of course, to any long-time MySQL user, this is immediately obvious as the classical use-left-join-to-find-what-isn't-in-the-other-table:

代码如下:

SELECT DISTINCT a.member_id, a.name FROM a LEFT JOIN b USING (member_id, name) WHERE b.member_id IS NULL