假设我有表R1 =(A,B,C,D)和R2 =(X,Y)。
如何将以下结果保存到(临时)表
select * from R1, R2 where R1.A=R2.X (1)
同样,如果我想将选择结果保存到变量,例如,
select avg(C) from from R1, R2 where R1.A=R2.X (2)
此外,在更改某些字段的名称时,连接两个表的最佳优雅查询是什么,例如query(3)的最短等价物是什么?
select A, B, C, D, X as E, Y as F from from R1, R2 where R1.A=R2.X (3)
答案 0 :(得分:2)
(1) Create Temp Table tbl1 as
select * from R1 inner join
R2 on R1.A=R2.X
distribute on random
(2) Create Temp Table tbl2 as
select avg(c) as avg_c from R1 inner join
R2 on R1.A=R2.X
distribute on random
(3)使用as
是重命名结果列/字段的好方法