Extract First Matchin Record

Question

Hi,
This is my first post to this forum. I need some help in writting a bit complex query. there are two tables. which have 1-m relationship. for each record in table a i want to extract the first matching row from table b.in table b there are many matches but i want to extract the first match and ignore the rest for each value of the primary key in table A.
Table A
field1 field2
1 one
2 two
3 three
Table B
fieldb1 fieldb2 fieldb3
1 one 55
1 one 66
1 two 77
I want join on field1 and fieldb1 than check for condition where fieldb2 = one and fieldb3>0.so in this case it will return 2 records. but i want only the first match that is one 55.
Thanks in advance.
Raj.

Answer 1

Hi,
The query you posted:
SELECT ll1.ln_id,min(princ_apld_amt), ll1.crtlamt_apld_amt, ll1.actl_1001pct_upb_amt
FROM ll_ln_actvy00_1 ll1, ll_ln_actvy00_2 ll2
WHERE ll1.ln_id = ll2.ln_id
AND ll2.princ_apld_amt < ll1.crtlamt_apld_amt
group by ll1.ln_idis not what you're actually running.
The query above will cause the error "ORA-00979: not a GROUP BY" expression because there are columns in the SELECT clause ( ll1.crtlamt_apld_amt and ll1.actl_1001pct_upb_amt) that are not in the GROUP BY clause.
What is the data in your tables that is producing the output you posted? Forgive me if you already posted it, but the only sample data I found is in your very first message, and I don't see how this output comes from that data. (Though it is a long thread, and I may have missed something.)