查看“︁SQL:Join”︁的源代码

[[Image:Visual-join.png]]

=Example=
<syntaxhighlight lang="bash">
A    B
-    -
1    3
2    4
3    5
4    6
</syntaxhighlight>
==Inner Join==
<syntaxhighlight lang="bash">
select * from a INNER JOIN b on a.a = b.b;
select a.*, b.*  from a,b where a.a = b.b;

a | b
--+--
3 | 3
4 | 4
</syntaxhighlight>
==Left Join==
<syntaxhighlight lang="bash">
select * from a LEFT OUTER JOIN b on a.a = b.b;
select a.*, b.*  from a,b where a.a = b.b(+);

a |  b
--+-----
1 | null
2 | null
3 |    3
4 |    4
</syntaxhighlight>
==Right Join==
<syntaxhighlight lang="bash">
select * from a RIGHT OUTER JOIN b on a.a = b.b;
select a.*, b.*  from a,b where a.a(+) = b.b;

a    |  b
-----+----
3    |  3
4    |  4
null |  5
null |  6
</syntaxhighlight>
==Full Join==
<syntaxhighlight lang="bash">
select * from a FULL OUTER JOIN b on a.a = b.b;

 a   |  b
-----+-----
   1 | null
   2 | null
   3 |    3
   4 |    4
null |    6
null |    5
</syntaxhighlight>

[[Category:Database]]
[[Category:SQL]]