Question

我正在尝试执行一个查询，其中我传递了'seasson'，它向我显示了与排名中的驱动程序，积分，构造函数和位置相关的信息。

我想要的是这样的东西：

POS IN RANKING | DRIVER NAME | CONSTRUCTOR NAME | POINTS
---------------------------------------------------------
    1           "Hamilton"     MC Laren         360
    2           "Alonso"       Ferrari          290
   ...                 ...                   ....

我得到的问题是我无法枚举行。我认为“POS IN RANKING”应该是函数row_number（）的结果，但是对于某些reasson我不能使它工作。

这是我的存储功能：

CREATE TYPE ranking_t AS (
pos integer,
driver character varying(30),
constructor character varying(30),
points integer
);

CREATE OR REPLACE FUNCTION pra2.GetRankingOfPilots(sea pra2.season.name%type)
RETURNS ranking_t AS $$
DECLARE
    ranking_pilots ranking_t;
BEGIN
    SELECT  
      row_number() OVER (ORDER BY totalpuntos),
      driver.name driver, 
      constructor.name constructor,
      season.name season,
      CAST(sum(runs.points) AS int) TotalPuntos
    INTO ranking_pilots
    FROM 
      pra2.hired hired
    INNER JOIN pra2.constructor on  hired.name_constructor = pra2.constructor.name
    INNER JOIN pra2.driver on hired.num_driver = pra2.driver.num
    INNER JOIN pra2.runs on pra2.driver.num=pra2.runs.num_driver
    INNER JOIN pra2.race on pra2.runs.name_race=pra2.race.name AND pra2.runs.season_fk=pra2.race.season_fk AND pra2.runs.season_fk=pra2.race.season_fk
    INNER JOIN pra2.season on hired.name_season=pra2.season.name AND pra2.race.season_fk=pra2.season.name
    WHERE
        pra2.season.name=sea
    GROUP BY
        season,driver,constructor
    ORDER BY
        TotalPuntos Desc;

END; 
$$ 
LANGUAGE plpgsql;

我很感激任何建议。

提前谢谢！

Answer 1

在包装器查询中获取行号。

另外：将返回类型更改为SETOF ranking_t，删除变量并使用RETURN QUERY。

CREATE OR REPLACE FUNCTION pra2.GetRankingOfPilots(sea pra2.season.name%type)
RETURNS SETOF ranking_t AS $$
BEGIN
    RETURN QUERY
    SELECT row_number() OVER (ORDER BY totalpuntos)::int, *
    FROM (
        SELECT  
            driver.name driver, 
            constructor.name constructor,
            season.name season,
            CAST(sum(runs.points) AS int) TotalPuntos
        FROM 
            pra2.hired hired
        INNER JOIN pra2.constructor on  hired.name_constructor = pra2.constructor.name
        INNER JOIN pra2.driver on hired.num_driver = pra2.driver.num
        INNER JOIN pra2.runs on pra2.driver.num=pra2.runs.num_driver
        INNER JOIN pra2.race on pra2.runs.name_race=pra2.race.name AND pra2.runs.season_fk=pra2.race.season_fk AND pra2.runs.season_fk=pra2.race.season_fk
        INNER JOIN pra2.season on hired.name_season=pra2.season.name AND pra2.race.season_fk=pra2.season.name
        WHERE
            pra2.season.name=sea
        GROUP BY
            season,driver,constructor
        ) s
    ORDER BY
        TotalPuntos Desc;
END; 
$$ 
LANGUAGE plpgsql;

Answer 2

我想问题是你使用别名而不是源。

你不能这样做

SELECT row_number() OVER (ORDER BY totalpuntos)
FROM ( SELECT   CAST(sum(runs.points) AS int) TotalPuntos
       From YourQuery
     ) as Subquery

所以你创建一个子查询

OVER

也许你可以使用这个功能，但是SELECT row_number() OVER (ORDER BY CAST(sum(runs.points) AS int)),内部不确定是否可能。

CREATE OR REPLACE FUNCTION foo(a int)
RETURNS TABLE(b int, c int) AS $$
BEGIN
  RETURN QUERY SELECT i, i+1 FROM generate_series(1, a) g(i);
END;
$$ LANGUAGE plpgsql;

编辑：要返回您喜欢的表

{{1}}

PostgreSQL存储过程：如何枚举查询

2 个答案: