Mysql common SQL query scenarios

scene one:

　　A field of sport shooting, John Doe, Wang Wu three people participate in the competition.

　　Shooting rules of the game: a total of three games; after the end of three rounds, the best score to take rank as a personal best.

　　Design database tables:

CREATE TABLE `TEST` (
  `ID` int(11) NOT NULL,
  `NAME` varchar(45) DEFAULT NULL COMMENT '名称',
  `SCORE` int(11) DEFAULT NULL COMMENT '分数',
  `ROUND` int(11) DEFAULT NULL COMMENT '回合',
  PRIMARY KEY (`ID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

　　Inserting data:
　　　　three score down
　　　　Zhang 9,10,10 respectively;

　　　　John Doe 10,9,8 respectively;

　　　　King five are 9,8,8;

 

　　After sorting by known, to take the data to each data ID is 4,2,3

 　　By grouping names, names and get the best results created

　　It leads to the following table associated with the query results

　　At this time, the results need to be removed and the packet ID for each group the minimum value

　　The ID of the query and sort out

 

　　This is taken out in the same table each optimization data.

　　

　　Should coupled with a condition, when the last two data points the same, the higher the average score of ranking, the same is sorted by name.