SELECT sys_cities.cityid, sys_cities.city, sys_areas.areaid, sys_areas.area, departure_timetable.departure_id, departure_timetable.begin_area, departure_timetable.end_area, sys_cities_1.cityid AS Expr1,
sys_cities_1.city AS Expr2, sys_areas_1.areaid AS Expr3, sys_areas_1.area AS Expr4
FROM sys_areas INNER JOIN
departure_timetable ON sys_areas.areaid = departure_timetable.begin_area_id INNER JOIN
sys_cities ON sys_areas.cityid = sys_cities.cityid INNER JOIN
sys_areas AS sys_areas_1 ON departure_timetable.end_area_id = sys_areas_1.areaid INNER JOIN
sys_cities AS sys_cities_1 ON sys_areas_1.cityid = sys_cities_1.cityid
简单说一下表结构,基础表有省份表,城市表,地区表,然后有个发车表,里面有出发地i区d,目的地区ID,然后我通过发车表查找发车详细信息包括出发地城市地区和目的地城市地区,然后用mssql查询秒查出来,用mysql耗时446秒,求解这是什么原因
sys_cities_1.city AS Expr2, sys_areas_1.areaid AS Expr3, sys_areas_1.area AS Expr4
FROM sys_areas INNER JOIN
departure_timetable ON sys_areas.areaid = departure_timetable.begin_area_id INNER JOIN
sys_cities ON sys_areas.cityid = sys_cities.cityid INNER JOIN
sys_areas AS sys_areas_1 ON departure_timetable.end_area_id = sys_areas_1.areaid INNER JOIN
sys_cities AS sys_cities_1 ON sys_areas_1.cityid = sys_cities_1.cityid
简单说一下表结构,基础表有省份表,城市表,地区表,然后有个发车表,里面有出发地i区d,目的地区ID,然后我通过发车表查找发车详细信息包括出发地城市地区和目的地城市地区,然后用mssql查询秒查出来,用mysql耗时446秒,求解这是什么原因
explain select ...然后贴出结果。