选择值为NULL的列名

Question

好的,4个小时的编码,只有6个小时的搜索......我并没有比开始时更好.这是我的问题.我有一个表(tmpShell),它有12列.它是一个没有约束的基本表 - 用于临时报告.当我们插入数据时,我必须提取一个ID号(PatientId)和所有列NAMES,其中该PatientId的值为null.

例:

PatientId    Fname    Lname      DOB 
123455       Sam      NULL       NULL
2345455      NULL     Doe        1/1/1980
09172349     John     Jone       NULL

---

我想要回归的是:

PatientId    ErrorMsg
123455       Lname,DOB
2345455      Fname
09172349     DOB

当然,如果所有列都有值,则errormsg将为null.

我已尝试并失败了大约300个不同的代码片段,但这似乎是我能得到的最接近的代码.不幸的是,这只返回每一列,而不是空值.

     ALTER PROC [sp_aaShowAllNullColumns]
      @tableName VARCHAR(255)
     AS
      BEGIN
            SET NOCOUNT ON;


        DECLARE @sql NVARCHAR(4000);
        DECLARE @cols NVARCHAR(4000);
        DECLARE @tcols TABLE ( [colbit] NVARCHAR(255) );
        --DECLARE @tablename VARCHAR(255) = 'tmpShell';
        INSERT @tcols
                SELECT
                        'count(' + [columns].[name] + ') as ' + [columns].[name] + ', ' AS [colbit]
                    FROM
                        [sys].[columns]
                    WHERE
                        [columns].[object_id] = OBJECT_ID(@tableName);


        SELECT
                @cols = COALESCE(@cols, ', ', '') + [@tcols].[colbit]
            FROM
                @tcols;
        SELECT
                @cols = SUBSTRING(@cols, 1, ( LEN(@cols) - 1 ));
        SELECT
                @cols = ISNULL(@cols, '');

        SELECT
                @sql = 'select patientid, count(*) as Rows' + @cols + ' from ' + @tableName + ' group by patientid having count(*) > 0';
        CREATE TABLE [tmpShell2]
               (
                [patientid] VARCHAR(15)
               ,[Rows] CHAR(2)
               ,[Rn] CHAR(2)
               ,[patId] CHAR(2)
               ,[fname] CHAR(2)
               ,[lname] CHAR(2)
               ,[dob] CHAR(2)
               ,[addr1] CHAR(2)
               ,[city] CHAR(2)
               ,[state] CHAR(2)
               ,[zip] CHAR(2)
               ,[country] CHAR(2)
               ,[psite] CHAR(2)
               ,[csite] CHAR(2)
               ,[ssite] CHAR(2)
               ,[scode] CHAR(2)
               ,[sfid] CHAR(2)
               ,[taskid] CHAR(2)
               ,[errormsg] CHAR(2)
               );
        INSERT INTO [tmpShell2]
                EXEC [sys].[sp_executesql]
                    @sql;

        DECLARE @tbl VARCHAR(255) = 'tmpShell2';
        SELECT DISTINCT
                [TS].[patientid]
            ,   STUFF((
                        SELECT DISTINCT
                                ', ' + [C].[name]
                            FROM
                                [tmpShell2] AS [TS2]
                                JOIN [sys].[columns] AS [C]
                                ON [C].[object_id] = OBJECT_ID(@tbl)
                            WHERE
                      [C].[name] NOT IN ( 'SFID', 'TaskId',     'ErrorMsg' )
                                AND [C].[name] IS NOT NULL
                      FOR
                        XML PATH('')
                      ), 1, 1, '')
            FROM
                [tmpShell2] AS [TS];

        DROP TABLE [dbo].[tmpShell2];

  END;
 GO
 EXEC [sp_aaShowAllNullColumns]
'tmpShell';
</pre>

Answer 1

我认为你复杂的事情.

您可以尝试使用CASE EXPRESSION:

SELECT t.patientID,
       CASE WHEN t.fname is NULL THEN 'Fname,' ELSE '' END +
       CASE WHEN t.Lname is NULL THEN 'Lname,' ELSE '' END +
       CASE WHEN t.DOB is NULL THEN 'DOB,' ELSE '' END 
       ..... as ErrorMsg
FROM YourTable t

这将导致最后一个不必要的逗号errorMsg,为了处理它你可以这样做:

       REPLACE(CASE... +
               CASE... +
               CASE WHEN t.DOB is NULL THEN 'DOB,' ELSE '' END 
               ..... + ' ') ', ','') as ErrorMsg

这将使最后一个逗号唯一,因为它将有一个与其连接的空间,并确保只删除它.

Answer 2

像这样的事情怎么样？

SELECT
a.PatientID
, CASE a.tmpCol
    WHEN '' THEN NULL
    ELSE STUFF(a.tmpCol,1,1,'')
END AS ErrorMsg
FROM
(
SELECT
    PatientID
    , CASE WHEN FirstName IS NULL THEN ',FirstName' ELSE '' END
    + CASE WHEN LastName IS NULL THEN ',LastName' ELSE '' END
    + CASE WHEN DOB IS NULL THEN ',DOB' ELSE '' END AS tmpCol
FROM
    <tableName>
) a;