MS SQL讀取JSON數據

前面有一篇《在SQL中直接把查詢結果轉換為JSON數據》https://www.cnblogs.com/insus/p/10905566.html，是把table轉換為json。

現反過來，當SQL從前端接收過來的數據是JSON的話，需要把它轉換為TABLE。在MS SQL Server 2016有一個方法，OPENJSON。

DECLARE @json_text NVARCHAR(MAX)
SET @json_text = 
 N'
 {
     "DB Type":
     [
        {"type":"AF","desc":"聚合函數(CLR)"},
        {"type":"F","desc":"FOREIGN KEY 約束"},
        {"type":"FN","desc":"SQL 標量函數"},
        {"type":"FS","desc":"程式集(CLR)標量函數"},
        {"type":"FT","desc":"程式集(CLR)表值函數"},
        {"type":"RF","desc":"複製篩選過程"},
        {"type":"IF","desc":"SQL 內聯表值函數"},
        {"type":"TF","desc":"SQL 表值函數"}
     ]
 }'
   

讀取JSON文本的key,value,type和type說明：

SELECT [key],[value],[type],[dbo].[svf_JSONDataType]([type]) AS data_type FROM  
OPENJSON (@json_text)  

下麵是真正把JSON轉TABLE:

SELECT [type],[desc] FROM  
OPENJSON (@json_text ,'$."DB Type"')  
WITH
(
    [type] NVARCHAR(20) '$.type',
    [desc] NVARCHAR(40) '$.desc'
)