Improvements on sub-query projection reference.

sqlbuilder/projection.go

@@ -2,4 +2,29 @@ package sqlbuilder
 
 type projection interface {
 	serializeForProjection(statement statementType, out *queryData) error
+	from(subQuery ExpressionTable) projection
+}
+
+//------------------------------------------------------//
+// Dummy type for projection list
+type ProjectionList []projection
+
+func (cl ProjectionList) from(subQuery ExpressionTable) projection {
+	newProjectionList := ProjectionList{}
+
+	for _, projection := range cl {
+		newProjectionList = append(newProjectionList, projection.from(subQuery))
+	}
+
+	return newProjectionList
+}
+
+func (cl ProjectionList) serializeForProjection(statement statementType, out *queryData) error {
+	err := serializeProjectionList(statement, cl, out)
+
+	if err != nil {
+		return err
+	}
+
+	return nil
 }