COMMENT ON [ [ DATABASE | INDEX | RULE | SEQUENCE | TABLE | TYPE | VIEW ] object_name | COLUMN table_name.column_name| AGGREGATE agg_name agg_type| FUNCTION func_name (arg1, arg2, ...)| OPERATOR op (leftoperand_type rightoperand_type) | TRIGGER trigger_name ON table_name ] IS 'text'
给表mytable 加评注：
COMMENT ON mytable IS 'This is my table.';
一些例子：
COMMENT ON DATABASE my_database IS 'Development Database'; COMMENT ON INDEX my_index IS 'Enforces uniqueness on employee id'; COMMENT ON RULE my_rule IS 'Logs UPDATES of employee records'; COMMENT ON SEQUENCE my_sequence IS 'Used to generate primary keys'; COMMENT ON TABLE my_table IS 'Employee Information'; COMMENT ON TYPE my_type IS 'Complex Number support'; COMMENT ON VIEW my_view IS 'View of departmental costs'; COMMENT ON COLUMN my_table.my_field IS 'Employee ID number'; COMMENT ON AGGREGATE my_aggregate (double precision) IS 'Computes sample variance'; COMMENT ON FUNCTION my_function (timestamp) IS 'Returns Roman Numeral'; COMMENT ON OPERATOR ^ (text, text) IS 'Performs intersection of two text'; COMMENT ON TRIGGER my_trigger ON my_table IS 'Used for R.I.';