得到的所有数据

Question

我有以下表

Tbl_T1 
PRODUCT VALUE 

A  10 
C  30 

Tb1_T2 
PRODUCT VALUE 

B  20 
C  30 

我期待的输出

PRODUCT VALUE1 VALUE2 
A  10  0 
B  0  20 
C  30  30 

Answer 1

它被称为全外连接

select coalesce(t1.product, t2.product) as pr, 
     coalesce(t1.value, 0) as v1, 
     coalesce(t2.value, 0) as v2 
from t1 
full outer join t2 on t1.product = t2.product