(1) SIMPLE(简单SELECT,不使用UNION或子查询等) (2) PRIMARY(子查询中最外层查询,查询中若包含任何复杂的子部分,最外层的select被标记为PRIMARY) (3) UNION(UNION中的第二个或后面的SELECT语句) (4) DEPENDENT UNION(UNION中的第二个或后面的SELECT语句,取决于外面的查询) (5) UNION RESULT(UNION的结果,unio...
1.SIMPLE情况: mysql>EXPLAINSELECT*FROMcustomersWHEREcustomerName='Herkku Gifts'ANDphone='+47 2267 3215'ANDcustomerNumber=167;+---+---+---+---+---+---+---+---+---+---+---+---+|id|select_type|table|partitions|type|possible_keys|key|key_len|ref|rows|filtered|Extra|+---+--...
1 The Incident on the BusMilk St. Peter & the Unknown Knowns 2 Pussy Fear (Orange Crush)Milk St. Peter & the Unknown Knowns 3 Sunrise on the MoonMilk St. Peter & the Unknown Knowns 4 White Dreams & TicTacsMilk St. Peter & the Unknown Knowns 5 That One Time in the Green ...