Forum Discussion
Count Increased after Left join
Hello all,
I have two tables
Cntry, parts
In parts there are 30 columns and in cntry only 2 columns. I am doing Left join based on cntry_abb matching column in both tables Left tables is Parts and expaned the column Cntry_desc into parts table after join
I have 3.78M records in left table but after join it became 3.84, 8K difference I am getting.
How to get rid of this count increase issue?
Please Help
Thanks!!
Anonymous if you are linking from cntry table to part tables it will increase the count since there are duplicate in part table,
but if you are doing from part table to cntry table then the count of parts table will remain the same. It is very basic thing, not sure what is the confusion here.
5 Replies
Anonymous if you are linking from cntry table to part tables it will increase the count since there are duplicate in part table,
but if you are doing from part table to cntry table then the count of parts table will remain the same. It is very basic thing, not sure what is the confusion here.
Anonymous you have probably duplicate cntry_abb in parts tables.
Hi parry2k , I will be having duplicates too, but I don't know how count increased and why...
Anonymous it will increase the count:
assuming this
cntry table has following records:
USA
Canada
Product table has following records
USA
USA
Canada
Canada
and based on the above if you do a left join you will get 4 records because of duplicate in the Product table.