16.20 - Example: Query a 1-D ARRAY Data Type and Table using OLAST - Teradata Vantage NewSQL Engine

Teradata Vantage™ Data Types and Literals

Teradata Database
Teradata Vantage NewSQL Engine
March 2019
Programming Reference

Consider the following one-dimensional ARRAY data type and table.

CREATE TYPE phonenumbers AS VARRAY(20) OF CHAR(10);
CREATE TABLE employee_info (eno INTEGER, phonelist phonenumbers);

The table is populated with the following values:

/* The first 2 elements are populated; the rest are uninitialized. */
INSERT INTO employee_info VALUES (1, 
   phonenumbers('1112223333', '6195551234'));
/* Empty ARRAY instance */
INSERT INTO employee_info VALUES (2, 
/* Update empty ARRAY instance such that element 3 is set to a value;
   Then elements 1 and 2 are set to NULL, the rest are uninitialized */
UPDATE employee_info
SET phonelist[3] = '8584850000'
WHERE id = 2;

The following query returns the highest subscript value with a populated element in the phonelist array.

SELECT eno, phonelist.OLAST()
FROM employee_info;

The following is the result of the query.

ENO         phonelist.OLAST()
---         -----------------
 1           2
 2           3

The following is the same query using function-style syntax.

SELECT eno, OLAST(phonelist)
FROM employee_info;