在SQL中将动态列创建为VARCHAR MAX

Question

我正在使用标准SQL查询来确定需要索引的位置，但是为您提供建立索引的TSQL的列之一已被截断，因为索引中包含许多字段。 列本身也显示为截止。 我如何修改它，以便CreateIndexStatement是一个不会中断的VARCHAR MAX：

SELECT  sys.objects.name
, (avg_total_user_cost * avg_user_impact) * (user_seeks + user_scans) AS Impact
,  'CREATE NONCLUSTERED INDEX ix_IndexName ON ' + sys.objects.name COLLATE DATABASE_DEFAULT + ' ( ' + IsNull(mid.equality_columns, '') + CASE WHEN mid.inequality_columns IS NULL 
                THEN ''  
    ELSE CASE WHEN mid.equality_columns IS NULL 
                    THEN ''  
        ELSE ',' END + mid.inequality_columns END + ' ) ' + CASE WHEN mid.included_columns IS NULL 
                THEN ''  
    ELSE 'INCLUDE (' + mid.included_columns + ')' END + ';' AS CreateIndexStatement
, mid.equality_columns
, mid.inequality_columns
, mid.included_columns 
    FROM sys.dm_db_missing_index_group_stats AS migs 
            INNER JOIN sys.dm_db_missing_index_groups AS mig ON migs.group_handle = mig.index_group_handle 
            INNER JOIN sys.dm_db_missing_index_details AS mid ON mig.index_handle = mid.index_handle AND mid.database_id = DB_ID() 
            INNER JOIN sys.objects WITH (nolock) ON mid.OBJECT_ID = sys.objects.OBJECT_ID 
    WHERE     (migs.group_handle IN 
        ( 
        SELECT     TOP (500) group_handle 
            FROM          sys.dm_db_missing_index_group_stats WITH (nolock) 
            ORDER BY (avg_total_user_cost * avg_user_impact) * (user_seeks + user_scans) DESC))  
        AND OBJECTPROPERTY(sys.objects.OBJECT_ID, 'isusertable')=1 
    ORDER BY 2 DESC , 3 DESC 

Answer 1

只需将列表中的第一列转换为varchar(max)

SELECT cast(ColumnA as varchar(max))
      + ColumnB + ColumnC + .... + ColumnZ AS SomeColumn 
FROM SomeTable