atapia_

Nice piece of code providing the table was blank, but what happens when #New_Table already contains data as per below.

Insert into #New_Table

Values (1,'0000000000')

,(2, '1111111111')

,(3, '1111111111')

,(4, '2222222222')

,(5, '3333333333')

,(6, '2222222222')

the code provided would insert 3 more rows of 111111111, 2222222222 categories, thus breaking the Max of 3 rows per National_code.

The reason for this is that you dont take account of existing rows in New_Table which is a possibility according to the original poster.