Example: Query a 2-D ARRAY Data Type and Table using OTRIM - Advanced SQL Engine - Teradata Database

Consider the following 2-D ARRAY data type and table.

CREATE TYPE shot_ary AS VARRAY(1:50)(1:50) OF INTEGER;
CREATE TABLE seismic_table (
   id INTEGER,
   shots shot_ary);

The table is populated with the following values:

/* The first 2 elements are populated; the rest are uninitialized. */
INSERT INTO seismic_table VALUES (1, shot_ary(11, 12));
/* Empty ARRAY instance */
INSERT INTO seismic_table VALUES (2, shot_ary());
/* Update empty ARRAY instance such that element [1][3] is set to a value; Then elements [1][1] and [1][2] are set to NULL, the rest are uninitialized */
UPDATE seismic_table
SET shots[1][3] = 1133
WHERE id = 2;

The following query removes the last populated element from the shots array.

SELECT id, shots.OTRIM()
FROM seismic_table
WHERE id = 1;

The following is the result of the query.

ID          shots.OTRIM()
--          -------------
 1           (11)

The following query removes the last two populated elements from the shots array.

SELECT id, shots.OTRIM(2)
FROM seismic_table;

The following is the result of the query.

ID          shots.OTRIM(2)
--          --------------
 1           ()   (the only 2 populated elements were removed so we now
                   have an empty array value)
 2           (NULL)

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

SELECT id, OTRIM(shots, 2)
FROM seismic_table;