解析来自 SQL Server 表列的 JSON 数据

Question

我正在尝试从 SQL Server 2017 中的表中解析 JSON 数据。我有一个返回此数据的视图：

| Debrief Name      |  Version  |   Answer Question        | Answer Options                                                                                                           |  
+-------------------+-----------+--------------------------+--------------------------------------------------------------------------------------------------------------------------+  
| Observer Report   |  7        |   Division:              | {"Options":[{"Display":"Domestic","Value":"Domestic"},{"Display":"International","Value":"International"}]}              |  
| Observer Report   |  7        |   Are you on reserve?    | {"Options":[{"Display":"Yes - Long Call Line","Value":"Yes"},{"Display":"No","Value":"No"}]}                             |  
| Observer Report   |  11       |   Crew Position:         | {"Options":[{"Display":"CA","Value":"CA"},{"Display":"RC","Value":"RC"},{"Display":"FO","Value":"FO"}]}                  |      
| Observer Report   |  11       |   Domicile:              | {"VisibleLines":2,"Options":[{"Display":"BOS","Value":"BOS"},{"Display":"CLT","Value":"CLT"}]}                           |  
| Training Debrief  |  12       |   TRAINING CREW POSITION | {"VisibleLines":2,"Options":[{"Display":"CA","Value":"CA"},{"Display":"FO","Value":"FO"}]}                               |  
| Training Debrief  |  12       |   AIRCRAFT               | {"VisibleLines":2,"Options":[{"Display":"777","Value":"777"},{"Display":"767","Value":"767"}]}                           |      
| Security Debrief  |  9        |   Aircraft Type          | {"Options":[{"Display":"MD-80","Value":"MD-80"},{"Display":"777","Value":"777"},{"Display":"767/757","Value":"767/757"}]}|      
| News Digest       |  2        |   Do you read Digest?    | {"Options":[{"Display":"Yes","Value":"Yes"},{"Display":"No","Value":"No"}]}                                              |  

该Debrief Name列可以有相同的汇报名和多个记录Version。每个汇报也有多个版本。并且对于每个汇报名称和版本组合，都有一组Answer Questions和相关的Answer Options. 现在该列Answer Options包含我需要解析的 JSON 记录。

所以我的初始查询如下所示：

SELECT * 
FROM [dbo].<MY VIEW> 
WHERE [Debrief Name] = 'Observer Report' AND Version = 11

这将返回以下数据：

| Debrief Name        |    Version   |  Answer Question      |   Answer Options                                                                                                | 
+---------------------+--------------+-----------------------+-----------------------------------------------------------------------------------------------------------------+
| Observer Report     |    11        |  Crew Position:       |   {"Options":[{"Display":"CA","Value":"CA"},{"Display":"RC","Value":"RC"}]}                                     | 
| Observer Report     |    11        |  Domicile:            |   {"VisibleLines":2,"Options":[{"Display":"BOS","Value":"BOS"},{"Display":"CLT","Value":"CLT"}]}                |     
| Observer Report     |    11        |  Fleet:               |   {"Options":[{"Display":"330","Value":"330"},{"Display":"320","Value":"320"}]}                                 | 
| Observer Report     |    11        |  Division:            |   {"Options":[{"Display":"Domestic","Value":"Domestic"},{"Display":"International","Value":"International"}]}   |     
| Observer Report     |    11        |  Are you on reserve?  |   {"Options":[{"Display":"Yes - Long Call Line","Value":"Yes - Long Call Line"},{"Display":"No","Value":"No"}]} |     

现在从这个返回的结果中，对于每个Answer Question我需要解析相关的Answer OptionsJSON 数据并提取所有显示属性的 Value 字段。例如Answer Options，问题“你在储备中吗？”的 JSON 字符串。看起来像这样：

"Options":[
    {
        "Display":"330",
        "Value":"330",
        "Selected":false
    },
    {
        "Display":"320",
        "Value":"320",
        "Selected":false
    },
    {
        "Display":"S80",
        "Value":"S80",
        "Selected":false
    }
]

所以我需要提取“值”字段并返回类似值为 {330, 320, 195} 的数组的内容。

总之，我想构建一个查询，当我提供报告名称和版本号时，它会返回Answer Question所有Answer Option值。

我正在考虑使用如下存储过程：

CREATE PROCEDURE myProc 
    @DebriefName NVARCHAR(255), 
    @Version INT
AS
    SELECT * 
    FROM [dbo].[myView] 
    WHERE [Debrief Name] = @DebriefName 
      AND Version = @Version
GO;

然后有另一个存储过程，将从中捕获此结果myProc，然后进行 JSON 解析：

CREATE PROCEDURE parseJSON 
     @DebriefName NVARCHAR(255), 
     @Version INT
AS
    EXEC myProc @DebriefName, @Version; //Need to capture the result data in a temp table or something
    // Parse the JSON data for each question item in temp table
GO;

我不是 SQL 专家，所以不知道如何做到这一点。我在这里阅读了 SQL 中的 Json 解析，感觉我可以使用它，但不确定如何在我的上下文中使用。

Answer 1

如果您想解析Answer Options列中的JSON 数据并提取Value字段，您可以尝试使用以下方法，使用OPENJSON()和STRING_AGG()：

DECLARE @json nvarchar(max)
SET @json = N'{
   "Options": [
       {
       "Display": "330",
       "Value": "330",
       "Selected": false
       },
       {
       "Display": "320",
       "Value": "320",
       "Selected": false
       },   
       {
       "Display": "195",
       "Value": "195",
       "Selected": false
       }   
   ]
}'

SELECT STRING_AGG(x.[value], ', ') AS [Values]
FROM OPENJSON(@json, '$.Options') j
CROSS APPLY (SELECT * FROM OPENJSON(j.[value])) x
WHERE x.[key] = 'Value'

输出：

Values
330, 320, 195

如果要使用存储过程构建语句，请使用以下方法：

CREATE TABLE myTable (
   DebriefName nvarchar(100),
   Version int,
   AnswerQuestion nvarchar(1000),
   AnswerOptions nvarchar(max)
)
INSERT INTO myTable
   (DebriefName, Version, AnswerQuestion, AnswerOptions)
VALUES
   (N'Observer Report',  7,  N'Division:'             , N'{"Options":[{"Display":"Domestic","Value":"Domestic"},{"Display":"International","Value":"International"}]}'),
   (N'Observer Report',  7,  N'Are you on reserve?'   , N'{"Options":[{"Display":"Yes - Long Call Line","Value":"Yes"},{"Display":"No","Value":"No"}]}'),
   (N'Observer Report',  11, N'Crew Position:'        , N'{"Options":[{"Display":"CA","Value":"CA"},{"Display":"RC","Value":"RC"},{"Display":"FO","Value":"FO"}]}'),
   (N'Observer Report',  11, N'Domicile:'             , N'{"VisibleLines":2,"Options":[{"Display":"BOS","Value":"BOS"},{"Display":"CLT","Value":"CLT"}]}'),
   (N'Training Debrief', 12, N'TRAINING CREW POSITION', N'{"VisibleLines":2,"Options":[{"Display":"CA","Value":"CA"},{"Display":"FO","Value":"FO"}]}'),
   (N'Training Debrief', 12, N'AIRCRAFT'              , N'{"VisibleLines":2,"Options":[{"Display":"777","Value":"777"},{"Display":"767","Value":"767"}]}'), 
   (N'Security Debrief', 9,  N'Aircraft Type'         , N'{"Options":[{"Display":"MD-80","Value":"MD-80"},{"Display":"777","Value":"777"},{"Display":"767/757","Value":"767/757"}]}'),
   (N'News Digest',      2,  N'Do you read Digest?'   , N'{"Options":[{"Display":"Yes","Value":"Yes"},{"Display":"No","Value":"No"}]}')

SELECT 
   t.AnswerQuestion,
   STRING_AGG(x.[value], ', ') AS [Values]
FROM myTable t
CROSS APPLY (SELECT * FROM OPENJSON(t.AnswerOptions, '$.Options')) j
CROSS APPLY (SELECT * FROM OPENJSON(j.[value])) x
WHERE 
   DebriefName = N'Observer Report' AND
   t.Version = 11 AND
   x.[key] = 'Value'
GROUP BY 
   t.DebriefName,
   t.Version,
   t.AnswerQuestion

输出：

AnswerQuestion  Values
Crew Position:  CA, RC, FO
Domicile:       BOS, CLT