SQL窗口函数RANK(),Dense_Rank(）,row_number(),NTILE()

数据源

CREATE TABLE student(
  no int,
  ca varchar(20),
  name varchar(50),
  subject  varchar(50),
  scorce int
);

/* 数据 */
INSERT INTO student VALUES(1, '1班', '张三', '语文', 85);
INSERT INTO student VALUES(2, '1班', '张三', '数学', 90);
INSERT INTO student VALUES(3, '1班', '张三', '英语', 70);
INSERT INTO student VALUES(4, '1班', '李四', '语文', 70);
INSERT INTO student VALUES(5, '1班', '李四', '数学', 99);
INSERT INTO student VALUES(6, '1班', '李四', '英语', 62);
INSERT INTO student VALUES(7, '1班', '王五', '语文', 82);
INSERT INTO student VALUES(8, '1班', '王五', '数学', 74);
INSERT INTO student VALUES(9, '1班', '王五', '英语', 89);
INSERT INTO student VALUES(10, '2班', '刘晓希', '语文', 77);
INSERT INTO student VALUES(11, '2班', '刘晓希', '数学', 99);
INSERT INTO student VALUES(12, '2班', '刘晓希', '英语', 80);
INSERT INTO student VALUES(13, '2班', '朱鹏', '语文', 87);
INSERT INTO student VALUES(14, '2班', '朱鹏', '数学', 86);
INSERT INTO student VALUES(15, '2班', '朱鹏', '英语', 76);
INSERT INTO student VALUES(16, '2班', '欧阳雪', '语文', 91);
INSERT INTO student VALUES(17, '2班', '欧阳雪', '数学', 83);
INSERT INTO student VALUES(18, '2班', '欧阳雪', '英语', 77);

--  RANK() 排名
--  按照科目进行分区，每个区域按照分数进行排序，并得出排序结果的排名号。rank()是跳跃排序，有两个第1名，接下来就是第3名。
SELECT t.*,
       RANK() OVER (PARTITION BY t.subject ORDER BY t.scorce DESC) AS 排名
FROM student t

-- Dense_Rank(）密集排名
-- 按照科目进行分区，每个区域按照分数进行排序，并得出排序结果的排名号。dense_rank()为连续排序，有两个第1名，接下来就是第2名。
SELECT t.*,
       DENSE_RANK() OVER (PARTITION BY t.subject ORDER BY t.scorce DESC) AS 排名
FROM student t;

-- row_number()行号
SELECT t.*,
       ROW_NUMBER() OVER (PARTITION BY t.subject ORDER BY t.scorce DESC) AS 行号
FROM student t;

-- NTILE()查询结果分组
SELECT t.*,
       NTILE(6) OVER (PARTITION BY t.subject ORDER BY t.scorce DESC) AS 分组
FROM student t
ORDER BY 分组