SparkSQL和Hive在做cast boolean存在的不同

今天在看一些数据的时候发现,一些SparkSQL与Hive之间在进行cast转化时候存在一些差异。

HiveVersion 1.2.1
SparkSQL 1.6.0

总结:
在Hive中, boolean类型的隐式转化,Hive中非boolean非null转化默认为True,
而在SparkSQL中，则根据传入的不同数据类型判断值后返回结果.

Hive

Converts the results of the expression expr to . For example,
cast(‘1’ as BIGINT) will convert the string ‘1’ to its integral representation.
A null is returned if the conversion does not succeed.
If cast(expr as boolean) Hive returns true for a non-empty string.

hive> select cast('false' as boolean)  from default.dule;
OK
true

SparkSQL

在SparkSQL中如果是strin