如何在sql中创建具有参数的视图

我想创建一个带有参数的视图，然后像这样在此视图上进行选择

CREATE OR REPLACE FUNCTION statistiquess(dateDeb date, dateFin date)
RETURNS void AS
$$
     CREATE OR REPLACE VIEW statistics 
     AS 
      SELECT 
         e.matricule_ens, 
         e.nom_ens, 
         e.prenom_ens, 
         m.code_matiere, 
         m.nom_matiere, 
         f.id_formation, 
         f.nom_formation, 
         SUM ((CAST (c.heure_fin AS TIME))-(CAST (c.heure_deb AS TIME))) AS heure_total_programme, 
         SUM ((CAST (c.heure_dep_ens AS TIME))-(CAST (c.heure_arr_ens AS TIME))) AS heure_total_enseigne 
     FROM 
         enseignant e inner join cours c on e.matricule_ens = c.matricule_ens 
         inner join matiere m on c.code_matiere =  m.code_matiere 
         inner join formation f on f.id_formation = c.id_formation 
     WHERE
       c.jour between dateDeb and dateFin
     GROUP BY 
        e.matricule_ens, m.code_matiere, f.id_formation 
     ORDER BY 
        e.nom_ens;
$$
LANGUAGE SQL;

select * from statistiquess('2019-03-06', '2019-03-29');

当我尝试像这样从函数中选择all时，出现了这个错误

CREATE OR REPLACE FUNCTION statistiquess(dateDeb date, dateFin date)
RETURNS void AS
$$
     CREATE OR REPLACE VIEW statistics 
     AS 
      SELECT 
         e.matricule_ens, 
         e.nom_ens, 
         e.prenom_ens, 
         m.code_matiere, 
         m.nom_matiere, 
         f.id_formation, 
         f.nom_formation, 
         SUM ((CAST (c.heure_fin AS TIME))-(CAST (c.heure_deb AS TIME))) AS heure_total_programme, 
         SUM ((CAST (c.heure_dep_ens AS TIME))-(CAST (c.heure_arr_ens AS TIME))) AS heure_total_enseigne 
     FROM 
         enseignant e inner join cours c on e.matricule_ens = c.matricule_ens 
         inner join matiere m on c.code_matiere =  m.code_matiere 
         inner join formation f on f.id_formation = c.id_formation 
     WHERE
       c.jour between dateDeb and dateFin
     GROUP BY 
        e.matricule_ens, m.code_matiere, f.id_formation 
     ORDER BY 
        e.nom_ens;
$$
LANGUAGE SQL;

select * from statistiquess('2019-03-06', '2019-03-29');

错误：科隆«datedeb»不存在

LINE 6: ..._formation = c.id_formation where (c.jour between datedeb an...


QUERY:  
     CREATE OR REPLACE VIEW statistics AS select e.matricule_ens, e.nom_ens, e.prenom_ens, m.code_matiere, m.nom_matiere, f.id_formation, f.nom_formation, 
     SUM ((CAST (c.heure_fin AS TIME))-(CAST (c.heure_deb AS TIME))) AS heure_total_programme, 
     SUM ((CAST (c.heure_dep_ens AS TIME))-(CAST (c.heure_arr_ens AS TIME))) AS heure_total_enseigne 
     from enseignant e inner join cours c on e.matricule_ens = c.matricule_ens inner join matiere m on c.code_matiere =  m.code_matiere 
     inner join formation f on f.id_formation = c.id_formation where (c.jour between datedeb and datefin) 
     GROUP BY e.matricule_ens, m.code_matiere, f.id_formation ORDER BY e.nom_ens;

---

上面的语法具有

函数

而不是标题所述的视图。只有函数和存储过程可以接受参数。函数返回一个值，而存储过程不返回。问题是

视图是一种存储查询，您可以像查询任何其他表一样进行查询

SELECT * FROM statistiquess WHERE c.jour BETWEEN '2019-03-06' AND '2019-03-29';   

---

如果不了解您的数据和用例，就很难说您应该使用哪一个。从您的问题来看，您似乎需要一个视图或存储过程。

您不需要在函数内部创建视图来实现这一点。只需从函数中返回查询结果：

CREATE OR REPLACE FUNCTION statistiquess(dateDeb date, dateFin date)
RETURNS tables (matricule_ens text, nom_ens text, prenom_ens text, 
               code_matiere text, nom_matiere text, id_formation int,
               nom_formation text, heure_total_programme bigint, 
               heure_total_enseigne bigtin) AS
$$
    SELECT 
       e.matricule_ens, 
       e.nom_ens, 
       e.prenom_ens, 
       m.code_matiere, 
       m.nom_matiere, 
       f.id_formation, 
       f.nom_formation, 
       SUM ((CAST (c.heure_fin AS TIME))-(CAST (c.heure_deb AS TIME))) AS heure_total_programme, 
       SUM ((CAST (c.heure_dep_ens AS TIME))-(CAST (c.heure_arr_ens AS TIME))) AS heure_total_enseigne 
    FROM 
       enseignant e inner join cours c on e.matricule_ens = c.matricule_ens 
       inner join matiere m on c.code_matiere =  m.code_matiere 
       inner join formation f on f.id_formation = c.id_formation 
    WHERE
     c.jour between dateDeb and dateFin
    GROUP BY 
      e.matricule_ens, m.code_matiere, f.id_formation 
    ORDER BY 
      e.nom_ens;
$$
LANGUAGE SQL;

您必须调整返回列的数据类型（在

表（…）

part中）——我只是猜测它们可能是什么

然后您可以像“带参数的视图”一样使用它：

---

我的所有数据都在课程表中，该表包含课程开始时间、课程结束时间、教师到达时间、教师离开时间、教师标识符、科目标识符和培训标识符。因此，我想计算编程的总小时数，教学的总小时数，错过的总小时数，按科目分组，教师，两个日期之间的培训。您可以创建一个视图，每个事件有一行，并创建一个查询。或者您可以创建一个存储过程来输出您所需要的内容。视图将允许您对同一数据集提出不同的问题。如果只返回表，存储过程不是更好吗？@denov:不，使用（SQL）函数更好。首先，您可以针对函数的结果进行连接，并且可以在其上应用where条件（过程不可能），其次，如果函数用于更大的内容（例如连接），优化器可以内联查询。此外：如果将refcursor用作out参数，则过程只能“返回”某些内容。在SQL客户机中运行时使用非常复杂

select * 
from statistiquess('2019-03-06', '2019-03-29');