T-SQL :: 加入 sys.masked_columns returns table 中的所有列

T-SQL :: joining sys.masked_columns returns all columns in table

我正在尝试通过 sys.objects 加入 INFORMATION_SCHEMA.COLUMNSsys.masked_columns

这是我的查询:

SELECT
    TABLE_SCHEMA,
    TABLE_NAME, 
    COLUMN_NAME,
    DATA_TYPE
        + CASE WHEN DATA_TYPE IN ('char', 'nchar', 'varchar', 'nvarchar', 'binary', 'varbinary')
                    AND CHARACTER_MAXIMUM_LENGTH > 0 
                  THEN COALESCE('(' + CONVERT(varchar, CHARACTER_MAXIMUM_LENGTH) + ')', '')
                  ELSE '' 
          END
        + CASE WHEN DATA_TYPE IN ('decimal', 'numeric') 
                   THEN COALESCE('(' + CONVERT(varchar, NUMERIC_PRECISION) + ',' + CONVERT(varchar, NUMERIC_SCALE) + ')', '')
                   ELSE '' 
          END AS Declaration_Type,
    --CASE WHEN IS_NULLABLE='NO' THEN 'NOT ' ELSE '' END + 'NULL' AS Nullable
    m.is_masked,
    m.masking_function 
FROM
    INFORMATION_SCHEMA.COLUMNS c
JOIN
    sys.objects o ON c.table_name = o.name
JOIN 
    sys.masked_columns m ON o.[object_id] = m.[object_id] 
ORDER BY 
    1, 2, 3

和return是这样的:

TABLE_SCHEMA TABLE_NAME COLUMN_NAME Declaration_Type is_masked masking_function
Person EmailAddress BusinessEntityID int 1 email()
Person EmailAddress EmailAddress nvarchar(50) 1 email()
Person EmailAddress EmailAddressID int 1 email()
Person EmailAddress ModifiedDate datetime 1 email()
Person EmailAddress rowguid uniqueidentifier 1 email()

但是结果是错误的,因为它显示 Person.EmailAddress 中的所有列都被屏蔽了。

如果我检查这个查询:

SELECT c.name, tbl.name as table_name, c.is_masked, c.masking_function  
FROM sys.masked_columns AS c  
JOIN sys.tables AS tbl   
    ON c.[object_id] = tbl.[object_id]  
WHERE is_masked = 1;  

仅限 SSMS return 1 个屏蔽列:

name table_name is_masked masking_function
EmailAddress EmailAddress 1 email()

为什么 return 正在 Person.EmailAddress 中的每一列?

感谢@MartinSmith 和@JeroenMostert 在评论中提供的帮助。

正确的解决方案是去掉 INFORMATION_SCHEMA.* 列并改用 sys. 列:

mc.name AS column_name, 
mc.is_masked, 
mc.masking_function
, [Type]         = 
    CASE 
      WHEN tp.[name] IN ('varchar', 'char') THEN tp.[name] + '(' + IIF(mc.max_length = -1, 'max', CAST(mc.max_length AS VARCHAR(25))) + ')' 
      WHEN tp.[name] IN ('nvarchar','nchar') THEN tp.[name] + '(' + IIF(mc.max_length = -1, 'max', CAST(mc.max_length / 2 AS VARCHAR(25)))+ ')'      
      WHEN tp.[name] IN ('decimal', 'numeric') THEN tp.[name] + '(' + CAST(mc.[precision] AS VARCHAR(25)) + ', ' + CAST(mc.[scale] AS VARCHAR(25)) + ')'
      WHEN tp.[name] IN ('datetime2') THEN tp.[name] + '(' + CAST(mc.[scale] AS VARCHAR(25)) + ')'
      ELSE tp.[name]
    END
FROM sys.masked_columns AS mc  
JOIN sys.tables AS tbl ON mc.[object_id] = tbl.[object_id]  
JOIN sys.types tp ON mc.user_type_id = tp.user_type_id
WHERE mc.is_masked = 1;