范围比较 数字和字符串比较 字符串被转为double SELECT i FROM t WHERE i <= all {'11','12'}; i ============= 1 2 3 4 字符串和日期时间比较 字符串转为日期或时间 SELECT s FROM t2; s ====================== '01/01/2000' '01/01/1999' '01/01/1998' SELECT s FROM t2 WHERE s <= ALL {date'02/02/1998',…