json - 如何在数组数组上使用 JSON_MODIFY？

Question

我的结构看起来像这样

Declare @layout NVARCHAR(MAX) = N'
    {
        "Sections": [
            {
                "SectionName":"Section1",
                "SectionOrder":1,
                "Renders":[
                    {
                        "RenderName":"Render1",
                        "RenderOrder":1,
                        "Fields":[
                            {
                                "FieldName":"Field1",
                                "FieldData":"Data1"
                            },
                            {
                                "FieldName":"Field2",
                                "FieldData":"Data2"
                            }
                        ]
                    },
                    {
                        "RenderName":"Render2",
                        "RenderOrder":2,
                        "Fields":[
                            {
                                "FieldName":"Field1",
                                "FieldData":"Data1"
                            },
                            {
                                "FieldName":"Field2",
                                "FieldData":"Data2"
                            }
                        ]
                    } 
                ]
            },
            {
                "SectionName":"Section2",
                "SectionOrder":2,
                "Renders":[
                    {
                        "RenderName":"Render1",
                        "RenderOrder":1,
                        "Fields":[
                            {
                                "FieldName":"Field1",
                                "FieldData":"Data1"
                            }
                        ]
                    },
                    {
                        "RenderName":"Render2",
                        "RenderOrder":2,
                        "Fields":[
                            {
                                "FieldName":"Field1",
                                "FieldData":"Data1"
                            },
                            {
                                "FieldName":"Field2",
                                "FieldData":"Data2"
                            }
                        ]
                    } 
                ]
            }
        ]
    }
'

我想做的是这样做:

update FieldData = 'DataUpdated' 
where FieldName = 'Field2' 
and RenderName = 'Render'
and SectionName = 'Section1'

我将如何使用 JSON_MODIFY 做到这一点？

I can GET the data using the following query:

SELECT SectionName, SectionOrder, RenderName, RenderOrder, FieldName, FieldData FROM (
    SELECT SectionName, SectionOrder, RenderName, RenderOrder, Fields FROM (
        select SectionName, SectionOrder, Renders
        from OPENJSON(@layout,'$.Sections') 
        WITH (
            SectionName nvarchar(MAX) '$.SectionName',  
            SectionOrder nvarchar(MAX) '$.SectionOrder', 
            Renders nvarchar(MAX) '$.Renders' as JSON
        )
    ) as Sections
    CROSS APPLY OPENJSON(Renders,'$')
    WITH (
        RenderName nvarchar(MAX) '$.RenderName',  
        RenderOrder nvarchar(MAX) '$.RenderOrder', 
        Fields nvarchar(MAX) '$.Fields' as JSON
    )
) as Renders
CROSS APPLY OPENJSON(Fields,'$')
WITH (
    FieldName nvarchar(MAX) '$.FieldName',  
    FieldData nvarchar(MAX) '$.FieldData'
)

Answer 1

这并不像人们希望的那样简单。我很惊讶似乎没有简单的方法来查询 JSON 结构中项目的完整路径。

JSON_MODIFY 只能在定位数组成员时接受数组索引，因此这里的大部分工作都用于为每个嵌套数组成员生成索引。看来[key]列只能在使用 OPENJSON 时生成没有 WITH子句，所以我不能重用你的查询。

此外，JSON_MODIFY将只接受 JSON 路径的字符串文字，因此必须使用动态 SQL 执行更新。

(请注意，此解决方案假定您要更新特定的 RenderName，例如 'Render1' - 在这一点上问题不清楚。)

DECLARE @path nvarchar(2048)

SELECT @path = FORMATMESSAGE('SET @layout = JSON_MODIFY(@layout, ''$.Sections[%s].Renders[%s].Fields[%s].FieldData'', @newValue)' ,sectionindex, renderindex, [key])
FROM
(
    SELECT sectionindex, sectionName, b.[key] as renderindex, b.[value] AS bvalue, JSON_VALUE([Value], '$.RenderName') AS renderName
    FROM
        (SELECT [key] AS sectionindex, [Value] AS avalue, JSON_VALUE([Value], '$.SectionName') AS sectionName
        FROM OPENJSON(@layout, '$.Sections') ) AS sections
        CROSS APPLY OPENJSON(sections.avalue, '$.Renders') AS b
    ) AS renders
    CROSS APPLY OPENJSON(renders.bvalue,'$.Fields'
) AS d
WHERE JSON_VALUE([Value], '$.FieldName') = 'Field2' 
AND RenderName = 'Render1'
AND SectionName = 'Section1'

-- execute the update; this has to happen in dynamic SQL because the JSON_MODIFY path has to be a literal value, and cannot be a variable
EXEC sp_executeSQL @path, N'@layout nvarchar(max) OUTPUT, @newValue nvarchar(max)', @layout = @layout OUTPUT, @newValue = 'DateUpdated'

--check the results
SELECT sectionindex, sectionName, renderindex, rendername, [key] AS fieldindex, JSON_VALUE([Value], '$.FieldName') AS FieldName, JSON_VALUE([Value], '$.FieldData') AS FieldName
FROM
(
    SELECT sectionindex, sectionName, b.[key] AS renderindex, b.[value] AS bvalue, JSON_VALUE([Value], '$.RenderName') AS renderName
    FROM
        (SELECT [key] as sectionindex, [Value] as avalue, JSON_VALUE([Value], '$.SectionName') AS sectionName
        FROM OPENJSON(@layout, '$.Sections') ) AS sections
        CROSS APPLY OPENJSON(sections.avalue, '$.Renders') AS b
    ) AS renders
    CROSS APPLY OPENJSON(renders.bvalue,'$.Fields'
) AS d