Remove NOT NULL constraint on object_xref.analysis_id

sql/patch_53_54_c.sql

@@ -6,7 +6,7 @@
 # Add analysis_xref column to object_xref, copy values from identity_xref, remove column from identity_xref.
 # Will allow all object_xref relationships to have an analysis, not just those from sequence matching.
 
-ALTER TABLE object_xref ADD COLUMN analysis_id SMALLINT UNSIGNED NOT NULL;
+ALTER TABLE object_xref ADD COLUMN analysis_id SMALLINT UNSIGNED;
 
 UPDATE object_xref ox, identity_xref ix SET ox.analysis_id=ix.analysis_id WHERE ox.object_xref_id=ix.object_xref_id;
 

sql/table.sql

@@ -691,7 +691,7 @@ CREATE TABLE object_xref (
                               NOT NULL,
   xref_id                     INT UNSIGNED NOT NULL,
   linkage_annotation          VARCHAR(255) DEFAULT NULL,
-  analysis_id                 SMALLINT UNSIGNED NOT NULL,
+  analysis_id                 SMALLINT UNSIGNED,
 
   UNIQUE (ensembl_object_type, ensembl_id, xref_id),
   KEY oxref_idx (object_xref_id, xref_id, ensembl_object_type, ensembl_id),