Question

I am stuck on a query to generate a temporary table having values according to the following condition.

I have a table as follows (Table1)

ID
1
5
9
3
10

I want a new record set according to the ID column value, like if I have ID=1, I need 1 row, if ID=5 I need five rows and so on in the temp table, so the out put table will look something like:

ID    Val
1     Null
5     Null
5     Null
5     Null
5     Null
5     Null

and so on..

I am using two loops to achieve this, one loop is through ID and inner loop through ID value, but I believe there must be a simpler way to do this.

Answer 1

You could use a numbers table. Here I use spt_values that has a highest value of 2047. If that is not enough for you you should create a numbers table of your own.

declare @T table(ID int)

insert into @T values (1),(5),(9),(3),(10)

select T.ID
from @T as T
  inner join master..spt_values as N
    on N.number between 1 and T.ID
where N.type = 'P'    
order by T.ID