Question

Sr. ID   FName    LName    Mark
1   P1   amar     ranjan   100
2   P2   sameer   kumar    200
3   P1   amar     ranjan   200

Here I updated the first row for Mark column.

On each update to a single row I am creating the new row (see row 3) with updated value.
Is it possible to get the column name which have been updated in the table?

Answer 1

I used Mahmoud Gamal’s answer and SQL Fiddle demo as a starting point.

What you need is possible, but if you have access to the update processes I would recommand to manage the updates in any a stored procedure which saved the changes directly in a table.

If you need a trigger, something like this can work, but as you see, it has it’s own drawbacks: two temporary table because of the scope and a cursor.

It basicly generates a check for each column each time and inserts the new and old values for a column into the history table.

(a change on the ID column to Primary Key and Identity is recommanded too)

I also made an SQL FIDDLE demo

CREATE TABLE TableName (Sr INT, ID VARCHAR(10), FName VARCHAR(50),
LName VARCHAR(50), Mark VARCHAR(50));

CREATE TABLE HistoryTable (ID VARCHAR(10), ColumnName VARCHAR(50),
PrevValue VARCHAR(50), NewValue VARCHAR(50));



INSERT INTO TableName VALUES
(1, 'P1', 'amar', 'ranjan' , 100),
(2, 'P2', 'sameer', 'kumar', 200),
(3, 'P1', 'amar', 'ranjan', 200);



CREATE TRIGGER TableNameTrigger
ON TableName
AFTER UPDATE
AS 


SELECT * INTO #Deleted  FROM Deleted 
SELECT * INTO #Inserted FROM Inserted  

DECLARE @ColName varchar(64)
DECLARE columnCursor CURSOR FOR
SELECT COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'TableName' AND TABLE_SCHEMA='dbo'

OPEN columnCursor

FETCH NEXT FROM columnCursor INTO @ColName

WHILE (@@FETCH_STATUS <> -1)
BEGIN


EXEC(N'INSERT INTO HistoryTable 
     SELECT Deleted.Sr, ''' + @ColName + ''', Deleted.'+ @ColName + ',' + 'Inserted.' + @ColName +' 
     FROM #Deleted Deleted
     INNER JOIN #Inserted Inserted ON Inserted.Sr = Deleted.Sr
     WHERE Deleted.'+ @ColName + ' != Inserted.' + @ColName)




FETCH NEXT FROM columnCursor INTO @ColName

END


DROP TABLE #Deleted 
DROP TABLE #Inserted 

CLOSE columnCursor

DEALLOCATE columnCursor

GO