Implement RowsNextResultSet

driver.go

@@ -316,7 +316,37 @@ func (r *rowsImpl) Close() error {
 	return r.s.s.Reset()
 }
 
-// TODO HasNextResultSet && Stmt.tail ?
+func (r *rowsImpl) HasNextResultSet() bool {
+	return len(r.s.s.tail) > 0
+}
+
+func (r *rowsImpl) NextResultSet() error {
+	currentStmt := r.s.s
+	nextQuery := currentStmt.tail
+	var nextStmt *Stmt
+	var err error
+	for len(nextQuery) > 0 {
+		nextStmt, err = currentStmt.c.Prepare(nextQuery)
+		if err != nil {
+			return err
+		} else if nextStmt.stmt == nil {
+			// this happens for a comment or white-space
+			nextQuery = nextStmt.tail
+			continue
+		}
+		break
+	}
+	if nextStmt == nil {
+		return io.EOF
+	}
+	// TODO close vs reset ?
+	err = currentStmt.Finalize()
+	if err != nil {
+		return err
+	}
+	r.s.s = nextStmt
+	return nil
+}
 
 func (r *rowsImpl) ColumnTypeScanType(index int) reflect.Type {
 	switch r.s.s.ColumnType(index) {

driver_test.go

@@ -514,3 +514,66 @@ func TestNilAndEmptyBytes(t *testing.T) {
 		checkSqlRowsClose(rows, t)
 	}
 }
+
+func TestMultipleResultSets(t *testing.T) {
+	db := sqlOpen(t)
+	defer checkSqlDbClose(db, t)
+
+	rows, err := db.Query("SELECT 1; SELECT 2; SELECT 3")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer rows.Close()
+
+	var i int
+	for rows.Next() {
+		if err := rows.Scan(&i); err != nil {
+			t.Fatal(err)
+		}
+		if i != 1 {
+			t.Fatalf("expected 1, got %d", i)
+		}
+	}
+	if !rows.NextResultSet() {
+		t.Fatal("expected more result sets", rows.Err())
+	}
+	for rows.Next() {
+		if err := rows.Scan(&i); err != nil {
+			t.Fatal(err)
+		}
+		if i != 2 {
+			t.Fatalf("expected 2, got %d", i)
+		}
+	}
+
+	// Make sure that if we ignore a result we can still query.
+
+	rows, err = db.Query("select 4; select 5")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		if err := rows.Scan(&i); err != nil {
+			t.Fatal(err)
+		}
+		if i != 4 {
+			t.Fatalf("expected 4, got %d", i)
+		}
+	}
+	if !rows.NextResultSet() {
+		t.Fatal("expected more result sets", rows.Err())
+	}
+	for rows.Next() {
+		if err := rows.Scan(&i); err != nil {
+			t.Fatal(err)
+		}
+		if i != 5 {
+			t.Fatalf("expected 5, got %d", i)
+		}
+	}
+	if rows.NextResultSet() {
+		t.Fatal("unexpected result set")
+	}
+}