text: -- Copyright [1999-2013] Wellcome Trust Sanger Institute and the EMBL-European Bioinformatics Institute
  -- 
  -- Licensed under the Apache License, Version 2.0 (the "License");
  -- you may not use this file except in compliance with the License.
  -- You may obtain a copy of the License at
  -- 
  --      http://www.apache.org/licenses/LICENSE-2.0
  -- 
  -- Unless required by applicable law or agreed to in writing, software
  -- distributed under the License is distributed on an "AS IS" BASIS,
  -- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  -- See the License for the specific language governing permissions and
  -- limitations under the License.
  
  # patch_45_46_b.sql
  #
  # title: go_xref.source_xref_id
  #
  # description:
  #   Addition of a source_xref_id field to the go_xref table
  
  ALTER TABLE go_xref ADD COLUMN source_xref_id int(10) unsigned default NULL;
  
  ALTER TABLE go_xref DROP KEY object_xref_id_2;
  
  ALTER TABLE go_xref ADD UNIQUE KEY object_xref_id_2 
    ( object_xref_id, linkage_type, source_xref_id );
  
  ALTER TABLE go_xref ADD KEY source_xref_id( source_xref_id );
  
  
  # patch identifier
  INSERT INTO meta (meta_key, meta_value) 
    VALUES ('patch', 'patch_45_46_b.sql|go_xref.source_xref_id');
  
  
  
  