Oracle左右全连接

 Oracle左右全连接  

  一．左连接 （返回左边表所有符合条件的）  
        select * from a left join b on a.id=b.id;
        select * from a, b where a.id=b.id(+); 

 

  二．右连接 (返回右边表所有符合条件的)

        select * from a right join b on a.id=b.id;
        select * from a, b where a.id(+)=b.id;

 

  三．内连接（和where相同）

       select * from a join b on a.id=b.id;
       select * from a, b where a.id=b.id;

 

  四．完全外部连接(左向外连接和右向外连接的合集)

       select * from a full join b on a.id=b.id;
       select * from a, b    where a.id = b.id(+)
         union 
       select * from a, b    where a.id(+) = b.id;

 

  五．完全连接，也叫交叉连接或者笛卡尔积(返回左表中的每一行与右表中所有行的组合)

      select * from a,b;
      select * from a cross join b;