Updated on 2022-07-12 GMT+08:00

Other Functions

Array Functions

Table 1 Array functions

Function

Return Data Type

Description

CARDINALITY(ARRAY)

INT

Return the element count of an array.

ELEMENT(ARRAY)

-

Return the sole element of an array with a single element. If the array contains no elements, null is returned. If the array contains multiple elements, an exception is reported.

Example:

The returned number of elements in the array is 3.

insert into temp select CARDINALITY(ARRAY[TRUE, TRUE, FALSE]) from source_stream;

HELLO WORLD is returned.

insert into temp select ELEMENT(ARRAY['HELLO WORLD']) from source_stream;

Attribute Access Functions

Table 2 Attribute access functions

Function

Return Data Type

Description

tableName.compositeType.field

-

Select a single field, use the name to access the field of Apache Flink composite types, such as Tuple and POJO, and return the value.

tableName.compositeType.*

-

Select all fields, and convert Apache Flink composite types, such as Tuple and POJO, and all their direct subtypes into a simple table. Each subtype is a separate field.