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//table1ºÍtable2ΪÁ½¸ö²âÊÔ±í Ëæ±ã²åÈ뼸ÌõÊý¾Ý
SQL> select * from table1;
ID NAME
---------- --------------------
1 wh
2 wp
3 wq
SQL> select * from table2;
ID NAME
---------- --------------------
4 wr
1 wh
//Õý³£²éѯ
SQL> select a.name,b.name
2 from table1 a,table2 b
3 where a.id=b.id;
NAME NAME
-------------------- --------------------
wh wh
//ÏÔʾ³ötable1ÖеÄËùÓмǼ table2ÖÐÎÞÏàÓ¦¼Ç¼ÔòÖÃNULL
SQL> select a.name,b.name
2 from table1 a,table2 b
3 where a.id=b.id(+);
NAME NAME
-------------------- --------------------
wh wh
wq
wp
//ÏÔʾ³ötable2ÖеÄËùÓмǼ table1ÖÐÎÞÏàÓ¦¼Ç¼ÔòÖÃNULL
SQL> select a.name,b.name
2 from table1 a,table2 b
3 where a.id(+)=b.id;
NAME NAME
-------------------- --------------------
wh wh
wr
//ºÇºÇ,ÕâÀï±¾Ïë³¢ÊÔÒ»ÏÂÈ«ÍâÁ¬½Ó,²»¹ýʹÓÃ(+)ºÃÏñ²»ÐÐ
SQL> select a.name,b.name
2 from table1 a,table2 b
3 where a.id(+)=b.id(+);
where a.id(+)=b.id(+)
*
ERROR at line 3:
ORA-01468: a predicate may reference only one outer-joined table
//×óÍâÁ¬½Ó
SQL> select a.name,b.name
2 from table1 a
3 left outer join table2 b
4 on a.id=b.id;
NAME NAME
-------------------- --------------------
wh wh
wq
wp
//ÓÒÍâÁ¬½Ó
SQL> select a.name,b.name
2 from table1 a
3 right outer join table2 b
4 on a.id=b.id;
NAME NAME
-------------------- --------------------
wh wh
wr
//ÓÒÍâÁ¬½Ó
SQL> select a.name,b.name
2 from table2 b
3 right outer join table1 a