Question

I have got a table which contains 5 column and query requirements:

update row no 8 (or id=8) set its column 2, column 3's value
            from id 9th column 2, column 3 value.

Means all value of column 2, 3 should be shifted to column 2, 3 of upper row (start from row no 8) and value of last row’s 2, 3 will be null

For example, with just 3 rows, the first row is untouched, the second to N-1^th rows are shifted once, and the N^th row has nulls.

 id  math  science sst hindi english
  1   11     12     13  14   15
  2   21     22     23  24   25
  3   31     32     33  34   35

The result of query of id=2 should be:

 id  math  science sst hindi english
  1   11     12     13  14   15
  2   31     32     23  24   25        //value of 3rd row (col 2,3) shifted to row 2
  3   null   null   33  34   35

This process should run for all rows whose id > 2

Please help me to create this update query

I am using MS sqlserver 2005

Answer 1

I THINK what you are looking for is something like…

UPDATE t1
   SET 
      t1.math = t2.math,
      t1.science = t2.science,
      etc...
   FROM 
      YourTable t1, 
      YourTable t2
   WHERE 
      t1.id+1 = t2.id

Notice the WHERE is for the first instance table’s ID +1 being equal to the ID in the second instance. So if on table 1 ID = 8, it will join to second instance’s ID = 9. At the end, if only 10 records, 10+1 would not have a match, and thus result in NULL.