Added to functions to Pgsql::Result to help in doing smart things based on a result.

- ftable, return from which table the column in the result originates
- ftableCol, returns the column number within that table (attnum)
Ofcourse columns can also be expressions in which case these functions return InvalidOid and 0.

pgsql/Pgsql_Result.cpp

@@ -43,7 +43,6 @@ ErrorDetails ErrorDetails::createErrorDetailsFromPGresult(const PGresult *result
 	return r;
 }
 
-
 Result::Result(PGresult *res)
 	: result(res)
 {
@@ -96,7 +95,6 @@ std::string Result::diagSqlState()
 	return s;
 }
 
-
 ErrorDetails Result::diagDetails()
 {
 //	ErrorDetails r;
@@ -170,7 +168,6 @@ inline void Result::rowRangeCheck(int row) const
 		throw std::range_error("row index out of range");
 }
 
-
 const char * Result::val(int col, int row) const
 {
 	colRangeCheck(col);
@@ -205,3 +202,15 @@ bool Result::null(int col, int row) const
 
 	return PQgetisnull(result, row, col);
 }
+
+Oid Result::ftable(int col) const
+{
+	colRangeCheck(col);
+	return PQftable(result, col);
+}
+
+int Result::ftableCol(int col) const
+{
+	colRangeCheck(col);
+	return PQftablecol(result, col);
+}

pgsql/Pgsql_Result.h

@@ -123,6 +123,15 @@ namespace Pgsql {
 		Oid type(int col) const;
 		bool null(int col, int row) const;
 
+		/// Return the oid of the table this is a column of
+		/// when the column isn't a table column InvalidOid is returned
+		/// when col is out of range a std::range_error is thrown
+		Oid ftable(int col) const;
+		/// Returns the attnum of col in its table, attnum is negative for system cols like oid
+		/// It is positive for user columns, 0 signals there is no direct table column mapping
+		/// when col is out of range a std::range_error is thrown
+		int ftableCol(int col) const;
+
 
 	//		iterator begin();
 	private: