Using TABLE as array in PL/SQL - plsql

Question

I am using this anonymous function to test a programming construct for inclusion in a larger script:
DECLARE
TYPE array IS TABLE OF VARCHAR2(255);
g_to array DEFAULT array ();
BEGIN
INSERT INTO g_to VALUES ('myaddy#internet.com');
END;
But, when I run it, I get:
*Error starting at line : 1 in command -
DECLARE
TYPE array IS TABLE OF VARCHAR2(255);
g_to array DEFAULT array ();
BEGIN
INSERT INTO g_to VALUES ('myaddy#internet.com');
END;
Error report -
ORA-06550: line 10, column 17:
PL/SQL: ORA-00942: table or view does not exist
ORA-06550: line 10, column 5:
PL/SQL: SQL Statement ignored
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action:*
Now, the array is clearly defined, so why is the INSERT failing?

Answer 1

When you place the array into a place where it needs to be interpreted by the SQL interpreter (as opposed to the PL/SQL interpreter), then the array must be a database object, rather than locally defined. This is the case when you want to select from an array, for instance.
However, in this case you're trying to do something that would be invalid even if the array were a database object. You simply can't specify a variable as the target of an INSERT statement no matter what its declaration is. To do this correctly you need to use SELECT... BULK COLLECT INTO...:
DECLARE
TYPE array IS TABLE OF VARCHAR2(255);
g_to array DEFAULT array ();
BEGIN
SELECT 'myaddy#internet.com' BULK COLLECT INTO g_to FROM dual;
END;
However, if you're just adding a static value into the array, you'd be better off skipping the context switch incurred by using SQL and insert the value directly:
DECLARE
TYPE array IS TABLE OF VARCHAR2(255);
g_to array DEFAULT array ();
BEGIN
g_to.extend
g_to(g_to.last) := 'myaddy#internet.com';
END;