relaxing the constraint to allow multiple templates per branch

sql/patch_2010-05-20.sql

+    # relaxing this constraint we allow more than 1 template per from-to-branch combination:
+    # (unfortunately, it does not make NULLs unique)
+
+ALTER TABLE dataflow_rule DROP INDEX from_analysis_id;
+ALTER TABLE dataflow_rule ADD UNIQUE KEY (from_analysis_id, to_analysis_url, branch_code, input_id_template(512));

sql/tables.sql

@@ -64,7 +64,7 @@ CREATE TABLE dataflow_rule (
   input_id_template   TEXT DEFAULT NULL,
 
   PRIMARY KEY (dataflow_rule_id),
-  UNIQUE KEY (from_analysis_id, to_analysis_url, branch_code)
+  UNIQUE KEY (from_analysis_id, to_analysis_url, branch_code, input_id_template(512))
 );