根据积分对用户进行排名 [英] rank users based on points

问题描述

我如何根据积分对以下用户进行排名.我非常感谢您的帮助.提前致谢 .

How can I rank the users below based on points .I really appreciate any help. Thanks in Advance .

http://sqlfiddle.com/#!2/374db/11

CREATE TABLE if not exists tblA
(
id int(11) NOT NULL auto_increment ,
sender varchar(255),
receiver varchar(255),
 msg varchar(255),
 date timestamp,
  points varchar(255),
  refno varchar(255),
 PRIMARY KEY (id)
);

CREATE TABLE if not exists tblB
(
id int(11) NOT NULL auto_increment ,
sno varchar(255),
name varchar(255),
 PRIMARY KEY (id)
);

CREATE TABLE if not exists tblC
(
id int(11) NOT NULL auto_increment ,
data varchar(255),
  refno varchar(255),
  extrarefno varchar(255),
 PRIMARY KEY (id)
);


INSERT INTO tblA (sender, receiver,msg,date,points,refno ) VALUES
('1', '2', 'buzz ...','2011-08-21 14:11:09','10','001'),
('1', '2', 'test ...','2011-08-21 14:12:19','20','002'),
('4', '2', 'test ...','2011-08-21 14:13:19','30','003'),
('1', '3', 'buzz ...','2011-08-21 14:11:09','10','004'),
('1', '3', 'test ...','2011-08-21 14:12:19','20','005'),
('1', '4', 'buzz ...','2011-08-21 14:11:09','10','006'),
('1', '4', 'test ...','2011-08-21 14:12:19','20','007'),
('3', '4', 'test ...','2011-08-21 14:13:19','20','008'),
('2', '4', 'test ...','2011-08-21 14:13:19','20','009');



INSERT INTO tblB (sno, name ) VALUES
('1', 'Aa'),
('2', 'Bb'),
('3', 'Cc'),
('4', 'Dd'),
('5', 'Ee'),
('6', 'Ff'),
('7', 'Gg'),
('8', 'Hh');


INSERT INTO tblC (data,refno,extrarefno ) VALUES
('data1', '001', '101'),
('data2', '002', '102'),
('data3', '003', '103'),
('data4', '004', '101'),
('data5', '005', '102'),
('data6', '006', '103'),
('data7', '007', '101'),
('data8', '008', '101'),
('data9', '009', '101');

sql

SELECT *
FROM (SELECT tblA.receiver, MAX(tblA.id) AS id
      FROM tblA
      GROUP BY  tblA.receiver
    ) subset JOIN
    tblA
    ON subset.receiver = tblA.receiver AND subset.id = tblA.id JOIN
    tblB
    on tblA.receiver = tblB.sno join
    tblC
    ON tblA.refno=tblC.refno ;

推荐答案

您可以使用 ORDER BY 对查询结果进行排序.因此，您可以按如下方式对 tblA 中的行进行排名:

You can order the results of a query using ORDER BY. So, you can rank the rows in tblA as follows:

SELECT *
FROM tblA
ORDER BY points

但是，我注意到您在点列中使用了 varchar.如果这是要保存数值，您可能需要 int 或 float.

However, I notice you are using varchar for the points column. If this is to hold a numerical value you probably want int or float.

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