不顯示某字段有重復的記錄 SQL語句

詳細解釋下需求：

    根據某字段（此例中為StateProvinceID）做判斷，如果發現表中該字段有重復值，則結果不顯示該條記錄。

一，最直接的方法，效率低

SELECT * FROM 
 (
        SELECT StateProvinceID FROM
        (
            SELECT COUNT(*) AS num ,ad.StateProvinceID 
                FROM Person.Address ad 
                  GROUP BY StateProvinceID
         )AS tt
         WHERE tt.num<2  --排除重復
     ) AS tab
   INNER JOIN Person.Address addr ON tab.StateProvinceID=addr.StateProvinceID

二、使用了CTE

with t1
 AS(
    SELECT 
    * FROM Person.Address --WHERE AddressID<200
  ),
     t2 
  AS(
    SELECT 
    COUNT(*) AS num ,
    t1.StateProvinceID 
    FROM t1 
    GROUP BY StateProvinceID
    )
SELECT * FROM T2 
   INNER JOIN T1 ON t2.StateProvinceID = t1.StateProvinceID
  WHERE t2.num<2

三、最終版

 with  t2 
  AS(
    SELECT 
    COUNT(*) AS num ,
    t1.StateProvinceID 
    FROM Person.Address t1
    GROUP BY StateProvinceID
    )  
SELECT * FROM 
(
  SELECT T2.StateProvinceID  FROM t2 WHERE num<2
  ) AS T3
INNER JOIN Person.Address t1 ON T3.StateProvinceID=t1.StateProvinceID

還聽到有人說可以寫個func來判斷存臨時表，本人沒有測試，在此沒有列出。