hive(让我凌乱的一天)
子查询 有两种 一种是在from中在from中相当于省去一张字段表 SELECT ... FROM(subquery)name... SELECT col FROM ( SELECT a+b AS col FROM t1) SELECT t3.olROM ( SELECT a+b AS col FROM t1 UNION ALL SELECT c+d AS cal FROM t2 ) t3 另外一种是在where中操作在where中的子查询相当于条件单字段 所以做不了多字段表(纯属个人理解) SELECT * FROM AWHERE A.a IN (SELECT foo FROM B); 其他支持的types 有 EXISTS and NOT EXISTS SELECT AFROM T1WHERE EXISTS(SELECT B FROM ).....

