有時候可以透過SQL句就能避免資料重複新增，當然也可以用老派的方式，先Select Count(1)確定沒有資料後再Insert，單句SQL就能做到，請參考以下適用於Oracle的情況：
INSERT INTO TABLE1 (Column1,
Column2,
Column3,
Column4)
SELECT 'Value1' Column1,
'Value2' Column2,
'Value3' Column3,
'Value4' Column4
FROM DUAL
WHERE NOT EXISTS
(SELECT *
FROM TABLE1
WHERE Column1 = 'Value1'
AND Column2 = 'Value2'
AND Column3 = 'Value3'
AND Column4 = 'Value4')
