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SQLDoug
Asked: 2018-05-02 10:42:43 +0800 CST

在 Azure SQL DB 中查询 JSON 以获得每行一个数组元素

  • 772

我在 SQL Azure 数据库实例中有一个存储过程，输入参数是一个格式如下的 JSON 字符串：

{
    "OrderNumber":["OD12034"],
    "Site":["New York"],
    "LineNumber":[1000,2000],
    "ItemNumber":["BX12345","BX12349"],
    "Quantity":[23,15]
}

我想对此进行解析，以便可以将记录插入到这样的表中：

ArrayKey    | ArrayElement
------------|-----------
OrderNumber | OD12034
Site        | New York
LineNumber  | 1000
LineNumber  | 2000
ItemNumber  | BX12345
ItemNumber  | BX12349
Quantity    | 23
Quantity    | 15

到目前为止，我已经能够从 JSON 中获取数据，但不是我想要的格式。这是一个简单的例子。

SELECT * FROM OPENJSON(@JsonParameter)

key              |value                      |type
-----------------|---------------------------|----
OrderNumber      |["OD12034"]                |4
Site             |["New York"]               |4
LineNumber       |[1000,2000]                |4
ItemNumber       |["BX12345","BX12349"]      |4
Quantity         |[23,15]                    |4

这是另一个（与简单化相反）的例子。

SELECT 
       [ON].OrderNumber
     , [S].Site
     , [LN].LineNumber
     , [IN].ItemNumber
     , [Q].Quantity
FROM OPENJSON(@JsonParameter)
    WITH (
         [OrderNumber]      NVARCHAR(MAX)   '$.OrderNumber'     AS JSON
        ,[Site]             NVARCHAR(MAX)   '$.Site'            AS JSON
        ,[LineNumber]       NVARCHAR(MAX)   '$.LineNumber'      AS JSON
        ,[ItemNumber]       NVARCHAR(MAX)   '$.ItemNumber'      AS JSON
        ,[Quantity]         NVARCHAR(MAX)   '$.Quantity'        AS JSON
    ) AS jsonValues
CROSS APPLY OPENJSON(jsonValues.OrderNumber)
    WITH (OrderNumber NVARCHAR(25) '$') AS [ON]
CROSS APPLY OPENJSON(jsonValues.Site)
    WITH (Site NVARCHAR(25) '$') AS [S]
CROSS APPLY OPENJSON(jsonValues.LineNumber)
    WITH (LineNumber INT '$') AS [LN]
CROSS APPLY OPENJSON(jsonValues.ItemNumber)
    WITH (ItemNumber NVARCHAR(31) '$') AS [IN]
CROSS APPLY OPENJSON(jsonValues.Quantity)
    WITH (Quantity INT '$') AS [Q]

OrderNumber  |Site        |LineNumber |ItemNumber    |Quantity
-------------|------------|-----------|--------------|-----------
OD12034      |New York    |1000       |BX12345       |23
OD12034      |New York    |1000       |BX12345       |15
OD12034      |New York    |1000       |BX12349       |23
OD12034      |New York    |1000       |BX12349       |15
OD12034      |New York    |2000       |BX12345       |23
OD12034      |New York    |2000       |BX12345       |15
OD12034      |New York    |2000       |BX12349       |23
OD12034      |New York    |2000       |BX12349       |15

有没有办法通过在 Azure SQL DB 中使用 JSON 工具来为每个数组元素获取一行？

t-sql azure-sql-database

1 个回答

  1. Best Answer

    好吧，我想出了一个答案，它给了我想要的结果，但它看起来很糟糕，我认为它效率低下。生成的计划的估计子树成本为 976507。这是查询。

    SELECT DISTINCT
    ArrayValues.ArrayKey
  , ArrayValues.ArrayElement 
FROM 
(
    SELECT 
           [ON].OrderNumber
         , [S].Site
         , [LN].LineNumber
         , [IN].ItemNumber
         , [Q].Quantity
    FROM OPENJSON(@JsonParameter)
        WITH (
             [OrderNumber]      NVARCHAR(MAX)   '$.OrderNumber'     AS JSON
            ,[Site]             NVARCHAR(MAX)   '$.Site'            AS JSON
            ,[LineNumber]       NVARCHAR(MAX)   '$.LineNumber'      AS JSON
            ,[ItemNumber]       NVARCHAR(MAX)   '$.ItemNumber'      AS JSON
            ,[Quantity]         NVARCHAR(MAX)   '$.Quantity'        AS JSON
        ) AS jsonValues
    CROSS APPLY OPENJSON(jsonValues.OrderNumber)
        WITH (OrderNumber NVARCHAR(31) '$') AS [ON]
    CROSS APPLY OPENJSON(jsonValues.Site)
        WITH (Site NVARCHAR(31) '$') AS [S]
    CROSS APPLY OPENJSON(jsonValues.LineNumber)
        WITH (LineNumber NVARCHAR(31) '$') AS [LN]
    CROSS APPLY OPENJSON(jsonValues.ItemNumber)
        WITH (ItemNumber NVARCHAR(31) '$') AS [IN]
    CROSS APPLY OPENJSON(jsonValues.Quantity)
        WITH (Quantity NVARCHAR(31) '$') AS [Q]
) ExpandedJson
UNPIVOT
(
    ArrayElement FOR ArrayKey IN (OrderNumber, Site, LineNumber, ItemNumber, Quantity)
) AS ArrayValues

    这是结果。

    ArrayKey       |ArrayElement
---------------|-------------
Quantity       |23
ItemNumber     |BX12345
Site           |New York
LineNumber     |1000
LineNumber     |2000
ItemNumber     |BX12349
Quantity       |15
OrderNumber    |OD12034
    • 2

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