无法在Hive中更改列的类型

Question

我想更改Hive表中某些列的类型。

首先，这是我的蜂巢表的描述：

hive (indicateurs)> describe adataindicateursf;
OK
nom                     string                  from deserializer
mod                     string                  from deserializer
val1                    string                  from deserializer
val2                    string                  from deserializer
val3                    string                  from deserializer
datar                   string                  from deserializer
cdb                     string                  from deserializer
met                     string                  from deserializer
env                     string                  from deserializer
ncre                    string                  from deserializer
app                     string                  from deserializer
type                    string                  from deserializer

然后将val2的类型更改为整数，并将val2的类型更改为双精度。

ALTER TABLE adataindicateursf CHANGE val2 val2 int AFTER val1;

ALTER TABLE adataindicateursf CHANGE val3 val3 double AFTER val2;

但是，没有任何变化：

describe adataindicateursf;
OK
nom                     string                  from deserializer
mod                     string                  from deserializer
val1                    string                  from deserializer
val2                    string                  from deserializer
val3                    string                  from deserializer
datar                   string                  from deserializer
cdb                     string                  from deserializer
met                     string                  from deserializer
env                     string                  from deserializer
ncre                    string                  from deserializer
app                     string                  from deserializer
type                    string                  from deserializer

这是什么问题？

Answer 1

Try this:  
ALTER TABLE adataindicateursf CHANGE val2 val2 int;  
ALTER TABLE adataindicateursf CHANGE val3 val3 double;  
if the above query are not working then try this:  
set hive.metastore.disallow.incompatible.col.type.changes=false   
when you set the properties then the types of columns in Metastore can be changed from any type to any other type.