PIG Latin中的JOIN条件

Question

SQL

SELECT m.x,m.y,n.a,n.b
from mydata1 m,mydata2 n
WHERE m.x=n.a
AND  m.y>= n.y

PIG

A = LOAD 'mydata1' AS (x: int, y: datetime);
B = LOAD 'mydata2' AS (a: int, b: datetime);  

我现在需要使用上面的sql条件加入这两个表。 如何使用连接条件在PIG中实现上述逻辑？

Answer 1

试试这个：

A = LOAD 'mydata1' AS (x: int, y: datetime);  
B = LOAD 'mydata2' AS (a: int, b: datetime); 
C = JOIN A BY x, B BY a;
D = FILTER C BY ToUnixTime(y) >= ToUnixTime(b);
DUMP D;