有没有办法在 PL/SQL SELECT 中声明日期变量

Question

我正在使用多个子查询从同一个表中提取多个日期范围内的数据。有没有办法设置日期变量，这样我就不必不断编辑日期范围？

例如：

Select A.Name,
    ,CASE
    WHEN B.WK1 IS NULL
    THEN 0
    ELSE B.WK1
    END as WK1

    ,CASE
    WHEN C.WK2 IS NULL
    THEN 0
    ELSE C.WK2
    END AS WK2

FROM

    (SELECT DISTINCT NAME
    FROM NAMES) A

    RIGHT OUTER JOIN
    (SELECT NAME,
    SUM(SALES) as WK1

    FROM SALES
    WHERE DATE between 1-JAN-2000 and 7-JAN-2000
    GROUP BY NAME) B
    ON NAME

    RIGHT OUTER JOIN
    (SELECT NAME,
    SUM(SALES) as WK2

    FROM SALES
    WHERE DATE between 8-JAN-2000 and 15-JAN-2000
    GROUP BY NAME) C
    ON NAME

基本上我想要做的是从一个日期开始滚动多周。

Answer 1

只需将您的日期值替换为绑定变量（例如 :date1），如下所示。第一次运行查询时，Toad 会询问您这些变量的值。之后，Toad 会记住您输入的值，因此它将预先填充相同的值，因此您不必再次键入它们。您还需要确保选择正确的数据类型。

Select A.Name,
    ,CASE
    WHEN B.WK1 IS NULL
    THEN 0
    ELSE B.WK1
    END as WK1

    ,CASE
    WHEN C.WK2 IS NULL
    THEN 0
    ELSE C.WK2
    END AS WK2

FROM

    (SELECT DISTINCT NAME
    FROM NAMES) A

    RIGHT OUTER JOIN
    (SELECT NAME,
    SUM(SALES) as WK1

    FROM SALES
    WHERE DATE between :date1 and :date2
    GROUP BY NAME) B
    ON NAME

    RIGHT OUTER JOIN
    (SELECT NAME,
    SUM(SALES) as WK2

    FROM SALES
    WHERE DATE between :date3 and :date4
    GROUP BY NAME) C
    ON NAME