Updated on 2023-03-21 GMT+08:00

Table-Valued Functions

Table-valued functions can convert one row of records into multiple rows or convert one column of records into multiple columns. Table-valued functions can only be used in JOIN LATERAL TABLE.

Table 1 Table-valued functions

Function

Return Data Type

Description

split_cursor(value, delimiter)

cursor

Separates the "value" string into multiple rows of strings by using the delimiter.

Example

Input one record ("student1", "student2, student3") and output two records ("student1", "student2") and ("student1", "student3").

create source stream s1(attr1 string, attr2 string) with (......);
insert into s2 select  attr1, b1 from s1 left join lateral table(split_cursor(attr2, ',')) as T(b1) on true;