CODE - TSQL convert Query to JSON

原文 ODE - TSQL convert Query to JSON 

TSQL - Query to JSON

It is my philosophy that good development starts with the data. I have always stressed whenever possible allow your data processing to take place on your SQL server or database processing engine and rendering of the data to the application control engine. By the time your application server receives the data it should be in the truncated, filtered, limited by rows, converted to correct formats, free of whitespace ect. Your application should only receive what it will use on the screen and nothing more. This however requires a developer to actually develop code, Stored Procedures and Functions.

This follows the same logical philosophy and creates a simple Query to JSON procedure.

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE[dbo].[SerializeJSON](
@ParameterSQL AS VARCHAR(MAX)
)
AS
BEGIN

DECLARE @SQL NVARCHAR(MAX)
DECLARE @XMLString VARCHAR(MAX)
DECLARE @XML XML
DECLARE @Paramlist NVARCHAR(1000)
SET @Paramlist = N '@XML XML OUTPUT'
SET @SQL = 'WITH PrepareTable (XMLString)'
SET @SQL = @SQL + 'AS('
SET @SQL = @SQL + @ParameterSQL+ 'FOR XML RAW,TYPE,ELEMENTS'
SET @SQL = @SQL + ')'
SET @SQL = @SQL + 'SELECT @XML=[XMLString]FROM[PrepareTable]'
EXEC sp_executesql @SQL, @Paramlist, @XML=@XML OUTPUT
SET @XMLString=CAST(@XML AS VARCHAR(MAX))

DECLARE @JSON VARCHAR(MAX)
DECLARE @Row VARCHAR(MAX)
DECLARE @RowStart INT
DECLARE @RowEnd INT
DECLARE @FieldStart INT
DECLARE @FieldEnd INT
DECLARE @KEY VARCHAR(MAX)
DECLARE @Value VARCHAR(MAX)

DECLARE @StartRoot VARCHAR(100);SET @StartRoot= '<row>'
DECLARE @EndRoot VARCHAR(100);SET @EndRoot= '</row>'
DECLARE @StartField VARCHAR(100);SET @StartField= '<'
DECLARE @EndField VARCHAR(100);SET @EndField= '>'

SET @RowStart=CharIndex(@StartRoot,@XMLString,0)
SET @JSON= ''
WHILE @RowStart>0
BEGIN
    SET @RowStart=@RowStart+Len(@StartRoot)
    SET @RowEnd=CharIndex(@EndRoot,@XMLString,@RowStart)
    SET @Row=SubString(@XMLString,@RowStart,@RowEnd-@RowStart)
    SET @JSON=@JSON+ '{'

    -- for each row
    SET @FieldStart=CharIndex(@StartField,@Row,0)
    WHILE @FieldStart>0
    BEGIN
        -- parse node key
        SET @FieldStart=@FieldStart+Len(@StartField)
        SET @FieldEnd=CharIndex(@EndField,@Row,@FieldStart)
        SET @KEY=SubString(@Row,@FieldStart,@FieldEnd-@FieldStart)
        SET @JSON=@JSON+ '"'+@KEY+'":'
        -- parse node value
        SET @FieldStart=@FieldEnd+1
        SET @FieldEnd=CharIndex( '</',@Row,@FieldStart)
        SET @Value=SubString(@Row,@FieldStart,@FieldEnd-@FieldStart)
        SET @JSON=@JSON+ '"'+@Value+'",'

        SET @FieldStart=@FieldStart+Len(@StartField)
        SET @FieldEnd=CharIndex(@EndField,@Row,@FieldStart)
        SET @FieldStart=CharIndex(@StartField,@Row,@FieldEnd)
    END
    IF LEN(@JSON)>0SET @JSON=SubString(@JSON,0,LEN(@JSON))
    SET @JSON=@JSON+ '},'
    --/ for each row

    SET @RowStart=CharIndex(@StartRoot,@XMLString,@RowEnd)
END
IF LEN(@JSON)>0SET @JSON=SubString(@JSON,0,LEN(@JSON))
SET @JSON= '['+@JSON+']'
SELECT @JSON

END
GO

Call thestored procedure

EXEC[SerializeJSON]'SELECT*FROM[Employee_TBL]'