如何在多行上使用 OPENJSON [英] How to use OPENJSON on multiple rows

问题描述

我有一个包含多行的临时表，每一行都有一个名为 Categories 的列；它包含一个非常简单的 ids json 数组，用于不同表中的类别.

I have a temp table with multiple rows in it and each row has a column called Categories; which contains a very simple json array of ids for categories in a different table.

临时表的几个示例行:

Id                                      Name    Categories
---------------------------------------------------------------------------------------------
'539f7e28-143e-41bb-8814-a7b93b846007'  Test 1  ["category1Id", "category2Id", "category3Id"]
'f29e2ecf-6e37-4aa9-aa56-4a351d298bfc'  Test 2  ["category1Id", "category2Id"]
'34e41a0a-ad92-4cd7-bf5c-8df6bfd6ed5c'  Test 3  NULL

现在我想做的是从临时表中的所有行中选择所有类别 ID.

Now what I would like to do is to select all of the category ids from all of the rows in the temp table.

我所拥有的是以下内容，但它无法正常工作，因为它给了我以下错误:

What I have is the following and it's not working as it's giving me the error of :

子查询返回了 1 个以上的值.当子查询跟在 =、!=、<、<=、>、>= 或当子查询用作表达式时，这是不允许的.

Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

SELECT
     c.Id
    ,c.[Name]
    ,c.Color
FROM
    dbo.Category as c
WHERE
    c.Id in (SELECT [value] FROM OPENJSON((SELECT Categories FROM #TempTable)))
and c.IsDeleted = 0

我认为失败是有道理的，因为我选择了多行并且需要解析每行各自的类别 ID json.我只是不知道该怎么做/改变才能给我想要的结果.在此先感谢您的帮助.

Which I guess it makes sense that's failing on that because I'm selecting multiple rows and needing to parse each row's respective category ids json. I'm just not sure what to do/change to give me the results that I want. Thank you in advance for any help.

推荐答案

你需要像这样使用 CROSS APPLY:

You'd need to use CROSS APPLY like so:

SELECT id ,
       name ,
       t.Value AS category_id
FROM   #temp
       CROSS APPLY OPENJSON(categories, '$') t;

然后，您可以使用 category_id 列加入您的 Categories 表，如下所示:

And then, you can JOIN to your Categories table using the category_id column, something like this:

SELECT id ,
       name ,
       t.Value AS category_id,
       c.*
FROM   #temp
       CROSS APPLY OPENJSON(categories, '$') t
       LEFT JOIN Categories c ON c.Id = t.Value

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