Question

I want to insert 3 rows at a time in a table based on select statement..

consider the query

insert into tblTemp 
(
a,b
)

select a, b from tblTemp2

This lets me insert one row in tblTemp..

my requirement is to add 3 rows with iterative values a,a+1,a+2 for each b inserted.

Answer 1

Use a cross join to generate extra rows (via Cartesian product), rather than querying tblTemp2 three times with UNION ALL

insert into tblTemp (a, b)
select a + offset, b
from
  tblTemp2
  cross join
  (SELECT 0 AS offset UNION ALL SELECT 1 UNION ALL SELECT 2) foo