Hive data types and their data conversions

Because of the need to use hive SQL for data queries, and the combination of several different types of fields, the document correlation and data for hive SQL are known, and hive supports the conversion between most of the underlying data types.

So, what data types does hive natively support?

From the hive built-in data types, the data types supported by hive include the following:

Data type	Occupied bytes	Start Support version
TINYINT	1byte,-128 ~ 127
SMALLINT	2byte,-32,768 ~ 32,767
Int	4byte,-2,147,483,648 ~ 2,147,483,647
BIGINT	8byte,-9,223,372,036,854,775,808 ~ 9,223,372,036,854,775,807
BOOLEAN
FLOAT	4byte Single Precision
DOUBLE	8byte Double Precision
STRING
BINARY		Support Starting from Hive0.8.0
TIMESTAMP		Support Starting from Hive0.8.0
DECIMAL		Support Starting from Hive0.11.0
CHAR		Support Starting from Hive0.13.0
VARCHAR		Support Starting from Hive0.12.0
DATE		Support Starting from Hive0.12.0

And some data data types: including array arrays, map key-value pairs, struct structures, union unions, and so on.

As you can see, hive supports the types of data that are used at all times.

At the same time, hive supports conversions between most of these data types.

Some of the underlying data types support implicit conversions, meaning that the source type can be used as the target type directly during use, and types that support data type implicit include:

Boolean

tinyint

smallint

int

bigint

float

Double

decimal

string

varchar

timestamp

Date

binary

Boolean

True

False

False

False

False

False

False

False

False

False

False

False

False

tinyint

False

True

True

True

True

True

True

True

True

True

False

False

False

smallint

False

False

True

True

True

True

True

True

True

True

False

False

False

int

False

False

False

True

True

True

True

True

True

True

False

False

False

bigint

False

False

False

False

True

True

True

True

True

True

False

False

False

float

False

False

False

False

False

True

True

True

True

True

False

False

False

Double

False

False

False

False

False

False

True

True

True

True

False

False

False

decimal

False

False

False

False

False

False

False

True

True

True

False

False

False

string

False

False

False

False

False

False

True

True

True

True

False

False

False

varchar

False

False

False

False

False

False

True

True

True

True

False

False

False

timestamp

False

False

False

False

False

False

False

False

True

True

True

False

False

Date

False

False

False

False

False

False

False

False

True

True

False

True

False

binary

False

False

False

False

False

False

False

False

False

False

False

False

True

At the same time, we can use cast to explicitly convert one type of data to another type of data.

If Hive does not support this type of conversion, an error will be made when using cast for conversion:

If you convert bigint to binary

CAST ((9223372036854775807-unix_timestamp ()) as binary)

The "invalid cast from bigint to binary" error is reported.

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