ALTER TABLE {{qual_table .SchemaName .TableName}}
  DROP CONSTRAINT IF EXISTS {{quote_ident .ConstraintName}};

ALTER TABLE {{qual_table .SchemaName .TableName}}
  ADD CONSTRAINT {{quote_ident .ConstraintName}}
  FOREIGN KEY ({{.SourceColumns}})
  REFERENCES {{qual_table .TargetSchema .TargetTable}} ({{.TargetColumns}})
  ON DELETE {{.OnDelete}}
  ON UPDATE {{.OnUpdate}}
  DEFERRABLE;