Archive for November, 2008

21 Nov 2008

Generating JSON from TSQL Query

No Comments SQL Server

I was looking for TSQL implementation which can build JSON payload directly from database. After couple of failed search, I decided to create my own stored procedure which can render JSON based for any query passed as parameter. After few keystrokes in SQL Server Management Studio, I have this semi-finish stored procedure which I thought you will find useful.

CREATE PROCEDURE [dbo].[GetJSON] (
@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)>0 SET @JSON = SubString(@JSON, 0, LEN(@JSON))
	SET @JSON = @JSON+'},'
	--/ for each row
 
	SET @RowStart = CharIndex(@StartRoot, @XMLString, @RowEnd)
END
IF LEN(@JSON)>0 SET @JSON = SubString(@JSON, 0, LEN(@JSON))
SET @JSON = '[' + @JSON + ']'
SELECT @JSON
 
END

To use this stored procedure, just pass TSQL query as parameter. Something like this:

EXEC GetJSON 'SELECT * FROM dbo.Employee_TBL'

And this stored procedure will return JSON payload:

[{"UserId":"7C92EB27-DD81-498E-82CE-18192C940328","FirstName":"Bill","LastName":"Gates","Age":"45","LastLogin":"2008-11-02T00:00:00"},{"UserId":"58E75687-8D0F-423A-8A76-4B1D750F62FD","FirstName":"Steve","LastName":"Job","Age":"52","LastLogin":"2008-10-17T00:00:00"}]
15 Nov 2008

Getting list of modified objects in SQL Server

No Comments SQL Server, Uncategorized

Developers always want to have a list of modified tables or stored procedures while check-in the code or wrapping up the development at the end of the day. some usually keep this list in text file and they update this file every time they modify any table or stored procedure. Here are some handy SQL snippets which can provide you list of the tables, or stored procedure modified in specific duration.

-- tables modified today
SELECT [name],create_date,modify_date
FROM sys.objects
WHERE modify_date>DATEADD(day,-1,GETDATE())
AND type='U'
-- stored procedures modified today
SELECT [name],create_date,modify_date
FROM sys.objects
WHERE modify_date>DATEADD(day,-1,GETDATE())
AND type='P'

You can further modify above queries to get list with objects modified in last 7 days.

-- tables modified in last 7 days
SELECT [name],create_date,modify_date
FROM sys.objects
WHERE modify_date>DATEADD(day,-7,GETDATE())
AND type='U'