sql - 使用参数调用函数或 View

Question

我想创建函数或 View ，每月显示特定年份的一些信息。

CREATE OR REPLACE VIEW name_view AS 
    SELECT d_name,
    SUM("Jan") "Jan",
    SUM("Feb") "Feb"
    ...
    FROM (
    select distinct d_name,
      COUNT(CASE WHEN EXTRACT (MONTH FROM h_date) = '01' THEN query_string ELSE NULL END) "Jan",
      COUNT(CASE WHEN EXTRACT (MONTH FROM h_date) = '02' THEN query_string ELSE NULL END) "Feb",
    ..
       from h
           inner join d on h_d = d_id
                WHERE EXTRACT (YEAR FROM h_date) = '2015' 
            GROUP BY  d_name) sub query
    GROUP BY d_name

如果没有

，我怎么能这样调用 View 呢？

WHERE EXTRACT (YEAR FROM h_date) = '2015'

但与通话年份有关？例如

SELECT * FROM name_view ('2015')

Answer 1

您应该在 SELECT 中使用 YEAR，当您从您使用 WHERE year = 2015 的 View 中进行 SELECT 时。

CREATE OR REPLACE VIEW name_view AS 
SELECT d_name,
SUM("Jan") "Jan",
SUM("Feb") "Feb",
YEAR,
....

View 的使用:

SELECT * 
FROM name_view 
WHERE year = '2015';