Question

出于某些原因，我必须从两个相关表中收集数据：

SELECT
    Company.id AS CompanyID,
    Company.name AS CompanyName,

    -- Get New Project ID
    convert(numeric,(CASE
        WHEN CHARINDEX('"new_project";s:1:"1"',CompanyInfo.data) > 0
        THEN (SELECT TOP(1) Project.id FROM Project
            WHERE Project.Company_id=Company.id
                AND (CAST(Project.CreateDate AS DATE)=CAST(CompanyInfo.date AS DATE)))
        ELSE NULL END
    )) as NewProjectID,

    -- Get New Project Name:
    (CASE
        WHEN CHARINDEX('"new_project";s:1:"1"',CompanyInfo.data) > 0
        THEN (SELECT TOP(1) Project.name FROM Project
            WHERE Project.Company_id=Company.id
                AND (CAST(Project.CreateDate AS DATE)=CAST(CompanyInfo.date AS DATE)))
        ELSE NULL END
    ) as NewProjectName,

    -- Get New Project Owner:
    (CASE
        WHEN CHARINDEX('"new_project";s:1:"1"',CompanyInfo.data) > 0
        THEN (SELECT TOP(1) Project.owner FROM Project
            WHERE Project.Company_id=Company.id
                AND (CAST(Project.CreateDate AS DATE)=CAST(CompanyInfo.date AS DATE)))
        ELSE NULL END
    ) as NewProjectOwner,

    ..........................
    -- Gets are go on like those above...
    -- Because MSSQL never merges sub-select results with main select result...
    ..........................

FROM 
    CompanyInfo
LEFT JOIN
    Company ON Company.id=CompanyInfo.Company_id

获取正如上面那样继续，因为MSSQL永远不会将子选择结果与主选择结果合并...

SQL Server不允许我使用“NewProjectID”别名，就像选择块中的变量一样：

SELECT

    -- Get New Project ID once:
    convert(numeric,(CASE
        WHEN CHARINDEX('"new_project";s:1:"1"',CompanyInfo.data) > 0
        THEN (SELECT TOP(1) Project.id FROM Project
            WHERE Project.Company_id=Company.id
                AND (CAST(Project.CreateDate AS DATE)=CAST(CompanyInfo.date AS DATE)))
        ELSE NULL END
    )) as NewProjectID,

    -- and use it for other subqueries:
    (SELECT Project.name FROM Project WHERE Project.id=NewProjectID) as ProjectName,
    (SELECT Project.owner FROM Project WHERE Project.id=NewProjectID) as ProjectOwner,
    (SELECT Project.addy FROM Project WHERE Project.id=NewProjectID) as ProjectAddy,
...........

我尝试过很多东西：

DECLARE @ProjectID int ;

SELECT
    -- Get New Project ID once:
    (@ProjectID = convert(numeric,(CASE
        .............
    ))) as NewProjectID,
.............

但是我遇到了错误，我错了，我只看到错误......

如何解决？

* PS： CompanyInfo.data列包含PHP样式的序列化数据，我无权重新设计表结构......

选择查询中的MSSQL动态变量赋值

0 个答案: