如何将三个MySQL查询合并为一个? [英] How to combine three MySQL queries into one?
问题描述
使用wordpress数据库,我们有wp_options和wp_postmeta之类的表. 这些按主键ID分组,然后按"option_name"和"option_value"之类的字段分组;
Using a wordpress database we have tables like wp_options, and wp_postmeta. These are grouped by primary key ID, then fields like 'option_name' and 'option_value';
例如,要找出三个值,我需要执行3个不同的查询.
So for example to find out three values I'd need to do 3 different queries.
是否有一种仅需一个查询即可完成所有这些操作的正确方法?
请对此有所了解,并分享正确的方法.
Please shed some light on this and share the right way to do this.
SELECT option_value FROM bdlocal_wrdp1.wp_options WHERE option_name='siteurl';
SELECT option_value FROM bdlocal_wrdp1.wp_options WHERE option_name='blogname';
SELECT option_value FROM bdlocal_wrdp1.wp_options WHERE option_name='blogdescription';
(返回example.com,示例博客,这是一个示例博客.)
(returns example.com, Example Blog, This is an example blog.)
推荐答案
SELECT option_name,
option_value
FROM bdlocal_wrdp1.wp_options
WHERE option_name IN ('siteurl', 'blogname', 'blogdescription')
执行此查询后,您将获得3对option_name + option_value
值.
And after this query execution you'll have 3 pairs of option_name + option_value
values.
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