Oracle裡的一些基本文法

1.串連

---內串連
select * from dali.test1 a, dali.test2 b where a.a=b.a;

---左串連
select * from dali.test1 a, dali.test2 b where a.a=b.a(+);

---右串連
select * from dali.test1 a, dali.test2 b where a.a(+)=b.a;

---完全串連
select * from dali.test1 a, dali.test2 b where a.a=b.a(+)
union
select * from dali.test1 a, dali.test2 b where a.a(+)=b.a;

---迪卡爾
select * from dali.test1, dali.test2;

 

 

判斷是否為空白：
   在SQl Server中為ISNULL(field1,0)
   在Oracle中為NVL(field1,0)