error in fill datagrid whit query

The schema returned by the new query differs from the base query

SELECT     B.SettingKey, 'SysSettingsDep' AS TableName, B.SettingValue, B.SettingDesc
FROM         SysCustomer AS A INNER JOIN
                      SysSettingsDep AS B ON A.SettingKey = B.SettingKey
UNION
SELECT     C.SettingKey, 'SysSettingsMachine' AS TableName, C.SettingValue, C.SettingDesc
FROM         SysCustomer AS A INNER JOIN
                      SysSettingsMachine AS C ON A.SettingKey = C.SettingKey
UNION
SELECT     D.SettingKey, 'SysSettings' AS TableName, D.SettingValue, D.SettingDesc
FROM         SysCustomer AS A INNER JOIN
                      SysSettings AS D ON A.SettingKey = D.SettingKey