Question

我有以下SQL查询，并且只需要运行一次df['date'] = pd.to_datetime(df['date'], dayfirst=True) df = df.set_index('date') df['new'] = df['value'].sub(df['value'].shift(freq='12MS')) print (df) value output new date 2012-01-01 20 NaN NaN 2012-02-01 10 NaN NaN 2012-03-01 40 NaN NaN 2012-06-01 30 NaN NaN 2013-01-01 20 0.0 0.0 2013-02-01 30 20.0 20.0 2014-02-01 60 30.0 30.0 2014-03-01 50 NaN NaN语句即可。

我可以知道我应该进行哪些更改吗？

编辑：需要更改以仅使用一个SELECT语句。

SELECT

如果@hideInactiveCompany = 1，则显示BU.IsActive = 1的输出

如果@hideInactiveCompany = 0，则显示不带BU.IsActive的输出   过滤器。

Answer 1

我们可以尝试编写以下WHERE子句：

WHERE
    (hideInactiveCompany = 1  AND BU.IsActive IS NOT NULL) OR
    (hideInactiveCompany IS NULL AND BU.IsActive IS NULL) OR
    (hideInactiveCompany <> 1)

注意：自从我回答后，OP改变了几次问题。最新的答案似乎是这样：

WHERE
    (hideInactiveCompany = 1 AND BU.IsActive = 1) OR
    hideInactiveCompany IS NULL OR hideInactiveCompany <> 1

Answer 2

如果我确实正确理解了您的要求，则整个查询应该只有一个SELECT子句

DECLARE
    @lang varchar(2) ='en',
    @hideInactiveCompany integer = 0

SELECT    <all columns>
FROM      Config.BusinessUnit BU
LEFT JOIN Config.Organization CO on BU.OrganizationId = CO.OrganizationId
LEFT JOIN Config.ParentBusinessUnit PBU on BU.ParentBusinessUnitId = PBU.ParentBusinessUnitId 
WHERE     (@hideInactiveCompany = 1 AND BU.IsActive = 1)
OR        (@hideInactiveCompany <> 1)
ORDER BY   CASE WHEN @lang = 'cn' THEN BU.Lang END,
           CASE WHEN @lang = 'en' THEN BU.Lang END DESC, 
           EntityName

WHERE上的说明基本上只有两个条件：-

条件1：@hideInactiveCompany = 1 AND BU.IsActive = 1
条件2：@hideInactiveCompany <> 1

条件1与您指定的条件相同。当变量@hideInactiveCompany为1时，IsActive必须为1

条件2是变量@hideInactiveCompany不等于1

Answer 3

您无法在SQL中执行这样的“有条件地构建我的选择”。您需要编写两次完整的选择查询，每个if的分支都要编写一次。

（SQL通常不是“可组合的”语言，您无法随意组合所需的元素。）

您也许可以使用case和其他表达式在单个查询中重建，或者将查询的公共部分放入临时表（或表值变量）中，然后仅将最后一部分进行两次。

Answer 4

使用IF ELSE条件：

ALTER PROCEDURE [Config].[usp_ListBusinessUnit] 
@lang VARCHAR(2) = NULL,
@hideInactiveCompany INTEGER
AS
BEGIN


IF @hideInactiveCompany=1
    SELECT <all columns>
    FROM Config.BusinessUnit BU
    LEFT JOIN Config.Organization CO ON BU.OrganizationId = CO.OrganizationId
    LEFT JOIN Config.ParentBusinessUnit PBU ON BU.ParentBusinessUnitId = 
PBU.ParentBusinessUnitId 
    WHERE BU.IsActive IS NOT NULL
    ORDER BY 
        CASE WHEN @lang = 'cn' THEN BU.Lang END,
        CASE WHEN @lang = 'en' THEN BU.Lang END DESC, 
        EntityName

ELSE

   SELECT <all columns>
    FROM Config.BusinessUnit BU
    LEFT JOIN Config.Organization CO ON BU.OrganizationId = CO.OrganizationId
    LEFT JOIN Config.ParentBusinessUnit PBU ON BU.ParentBusinessUnitId = 
PBU.ParentBusinessUnitId 
    WHERE BU.IsActive IS NULL
    ORDER BY 
    CASE WHEN @lang = 'cn' THEN BU.Lang END,
    CASE WHEN @lang = 'en' THEN BU.Lang END DESC, 
    EntityName

END

SQL Server：使用一个带有2个条件的Select语句

4 个答案: