Example: Query 1-D ARRAY Data Type and Table Using OPRIOR - Teradata Vantage

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, 
   phonenumbers());
/* 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 subscript of the element before element 2 in the phonelist array.

SELECT eno, phonelist.OPRIOR(2)
FROM employee_info;

The following is the result of the query.

ENO         phonelist.OPRIOR(2)
---         -------------------
 1           1
 2           1

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

SELECT eno, OPRIOR(phonelist, 2)
FROM employee_info;