+-- Create updatable view for series expressions,
+-- i.e. series of expressions separated by operators
+
+CREATE OR REPLACE VIEW query.expr_xser AS
+ SELECT
+ id,
+ parenthesize,
+ parent_expr,
+ seq_no,
+ operator,
+ negate
+ FROM
+ query.expression
+ WHERE
+ type = 'xser';
+
+CREATE OR REPLACE RULE query_expr_xser_insert_rule AS
+ ON INSERT TO query.expr_xser
+ DO INSTEAD
+ INSERT INTO query.expression (
+ id,
+ type,
+ parenthesize,
+ parent_expr,
+ seq_no,
+ operator,
+ negate
+ ) VALUES (
+ COALESCE(NEW.id, NEXTVAL('query.expression_id_seq'::REGCLASS)),
+ 'xser',
+ COALESCE(NEW.parenthesize, FALSE),
+ NEW.parent_expr,
+ COALESCE(NEW.seq_no, 1),
+ NEW.operator,
+ NEW.negate
+ );
+
+CREATE OR REPLACE RULE query_expr_xser_update_rule AS
+ ON UPDATE TO query.expr_xser
+ DO INSTEAD
+ UPDATE query.expression SET
+ id = NEW.id,
+ parenthesize = NEW.parenthesize,
+ parent_expr = NEW.parent_expr,
+ seq_no = NEW.seq_no,
+ operator = NEW.operator,
+ negate = NEW.negate
+ WHERE
+ id = OLD.id;
+
+CREATE OR REPLACE RULE query_expr_xser_delete_rule AS
+ ON DELETE TO query.expr_xser
+ DO INSTEAD
+ DELETE FROM query.expression WHERE id = OLD.id;
+