allow upsert for duplicate key

store/sqlstore/link_metadata_store.go

@@ -50,15 +50,23 @@ func (s SqlLinkMetadataStore) Save(metadata *model.LinkMetadata) (*model.LinkMet
 		return nil, errors.Wrap(err, "could not serialize metadataBytes to JSON")
 	}
 
-	query, args, err := s.getQueryBuilder().
+	query := s.getQueryBuilder().
 		Insert("LinkMetadata").
 		Columns("Hash", "URL", "Timestamp", "Type", "Data").
-		Values(metadata.Hash, metadata.URL, metadata.Timestamp, metadata.Type, string(metadataBytes)).
-		ToSql()
+		Values(metadata.Hash, metadata.URL, metadata.Timestamp, metadata.Type, string(metadataBytes))
+
+	if s.DriverName() == model.DatabaseDriverMysql {
+		query = query.SuffixExpr(sq.Expr("ON DUPLICATE KEY UPDATE URL = ?, Timestamp = ?, Type = ?, Data = ?", metadata.URL, metadata.Timestamp, metadata.Type, string(metadataBytes)))
+	} else {
+		query = query.SuffixExpr(sq.Expr("ON CONFLICT (hash) DO UPDATE SET URL = ?, Timestamp = ?, Type = ?, Data = ?", metadata.URL, metadata.Timestamp, metadata.Type, string(metadataBytes)))
+	}
+
+	q, args, err := query.ToSql()
 	if err != nil {
 		return nil, errors.Wrap(err, "metadata_tosql")
 	}
-	_, err = s.GetMasterX().Exec(query, args...)
+
+	_, err = s.GetMasterX().Exec(q, args...)
 	if err != nil && !IsUniqueConstraintError(err, []string{"PRIMARY", "linkmetadata_pkey"}) {
 		return nil, errors.Wrap(err, "could not save link metadata")
 	}