Question

Need to port data in sql table

I have a master table with columns (masterid, masterdata, year). Here masterid is an identity column.

I have the data for year 2012. I need to same 2012 data for 2013

I could solve the problem by simply running a SQL statement like:

INSERT INTO mastertable
    SELECT masterdata, 2013 
    FROM mastertable WHERE Year = 2012

I would like to run similar kind of run for child table also.

My child table structure is: (childid , masterid, childdata)

Here I have child data for the year 2012, I want to have similar data for year 2013 with proper masterid created for master data for the year 2013 in first step.

Preferably I would like to have solution without adding additional temporary columns

Any lead greatly appreciated.

Regards,
Kumar.

Answer 1

You’ll need to store the links between the 2013 and 2012 records created in the mastertable table. If you want to achieve this without adding any additional temporary columns you’ll need to use T-SQL.

(I’ve guessed a type of varchar(max) for masterdata as you haven’t specified its type).

DECLARE @links TABLE ( masterid int, newmasterid int )
DECLARE @mastertemp TABLE ( masterid int, masterdata varchar(max) )

DECLARE @masterid int,
        @masterdata varchar(max)

INSERT INTO @mastertemp
SELECT      masterid,
            masterdata
FROM        mastertable
WHERE       [year] = 2012

WHILE EXISTS ( SELECT TOP 1 * FROM @mastertemp )
BEGIN
    SELECT TOP 1    @masterid = masterid,
                    @masterdata = masterdata
    FROM            @mastertemp

    INSERT INTO mastertable
    VALUES ( @masterdata, 2013 )

    INSERT INTO @links
    VALUES ( @masterid, SCOPE_IDENTITY() )

    DELETE FROM @mastertemp
    WHERE       masterid = @masterid
END

INSERT INTO childtable
SELECT      l.newmasterid,
            c.childdata
FROM        childtable c
INNER JOIN  @links l ON c.masterid = l.masterid