I have 2 tables T1 and T2 T1 has the columns: D, S, C. The combination of D,S,C is unique. T2 has the columns: D, S, C, and boolean X. The combination of D,S,C is not unique.
I need to produce the following result for every occurrence of T1: D,S,C, COUNT COUNT is the number of matching D,S,C combinations in T2 where X = true. There might be no matching pair in T2 or there might be match but X is false. How can I express this? -- Best Regards, Tarlika Elisabeth Schmitz -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
