Why won't this PL/SQL function compile? - sql

Question

I'm learning about Oracle Apex, Oracle SQL and PL/SQL and I'm currently learning about functions. I have written a function in which a table is created, data is stored and the table is returned to the calling query. The problem is the code won't compile. I can't see where the problem may be and I've compared the code to various online resources including this site. Everything looks fine to me, so the answer is not obvious to me.
This is the code I wrote:
CREATE OR REPLACE TYPE t_table AS OBJECT
(
futureValues NUMBER
);
CREATE OR REPLACE TYPE t_futureValues AS TABLE OF t_table;
/
CREATE OR REPLACE FUNCTION "CALCULATE_VALUE"( lastRowMinus0 IN NUMBER DEFAULT 1,
lastRowMinus1 IN NUMBER DEFAULT 2,
lastRowMinus2 IN NUMBER DEFAULT 3,
lastRowMinus3 IN NUMBER DEFAULT 4,
lastRowMinus4 IN NUMBER DEFAULT 5,
lastRowMinus5 IN NUMBER DEFAULT 6,
lastRowMinus6 IN NUMBER DEFAULT 7 )
RETURN t_futureValues AS
tableObject t_futureValues;
predictedValue NUMBER := 0;
lastRowMinus0Value NUMBER := 0;
lastRowMinus1Value NUMBER := 0;
lastRowMinus2Value NUMBER := 0;
lastRowMinus3Value NUMBER := 0;
lastRowMinus4Value NUMBER := 0;
lastRowMinus5Value NUMBER := 0;
lastRowMinus6Value NUMBER := 0;
avgDiff NUMBER := 0;
BEGIN
tableObject := t_futureValues();
lastRowMinus0Value := 3;
lastRowMinus1Value := 6;
lastRowMinus2Value := 9;
lastRowMinus3Value := 12;
lastRowMinus4Value := 14;
lastRowMinus5Value := 20;
lastRowMinus6Value := 60;
avgDiff := (lastRowMinus5Value - lastRowMinus6Value) + avgDiff;
avgDiff := (lastRowMinus4Value - lastRowMinus5Value) + avgDiff;
avgDiff := (lastRowMinus3Value - lastRowMinus4Value) + avgDiff;
avgDiff := (lastRowMinus2Value - lastRowMinus3Value) + avgDiff;
avgDiff := (lastRowMinus1Value - lastRowMinus2Value) + avgDiff;
avgDiff := (lastRowMinus0Value - lastRowMinus1Value) + avgDiff;
avgDiff := avgDiff / 6;
predictedValue := avgDiff + lastRowMinus0Value;
begin
for i in 2..13 loop
predictedValue := predictedValue + avgDiff;
IF predictedValue < 0 THEN
predictedValue := 0;
END IF;
insert into tableObject(futureValues)
values(predictedValue);
end loop;
end;
RETURN (tableObject);
END;
The error message I get is:
ORA-06545: PL/SQL: compilation error - compilation aborted ORA-06550: line 6, column 1: PLS-00103: Encountered the symbol "CREATE" ORA-06550: line 0, column 0: PLS-00565: T_TABLE must be completed as a potential REF target (object type)
I have no doubt that the problem is something simple, so if anyone knows, then I'd be grateful.

Answer 1

I don't work with types very often, but your insert is trying to insert into an array. A table must be the target of an insert.
Use the following code:
CREATE OR REPLACE TYPE brianl.t_table AS OBJECT
(
futureValues NUMBER
);
CREATE OR REPLACE TYPE brianl.t_futureValues AS TABLE OF t_table;
/
CREATE OR REPLACE FUNCTION brianl."CALCULATE_VALUE"( lastRowMinus0 IN NUMBER DEFAULT 1,
lastRowMinus1 IN NUMBER DEFAULT 2,
lastRowMinus2 IN NUMBER DEFAULT 3,
lastRowMinus3 IN NUMBER DEFAULT 4,
lastRowMinus4 IN NUMBER DEFAULT 5,
lastRowMinus5 IN NUMBER DEFAULT 6,
lastRowMinus6 IN NUMBER DEFAULT 7 )
RETURN t_futureValues AS
tableObject t_futureValues;
predictedValue NUMBER := 0;
lastRowMinus0Value NUMBER := 0;
lastRowMinus1Value NUMBER := 0;
lastRowMinus2Value NUMBER := 0;
lastRowMinus3Value NUMBER := 0;
lastRowMinus4Value NUMBER := 0;
lastRowMinus5Value NUMBER := 0;
lastRowMinus6Value NUMBER := 0;
avgDiff NUMBER := 0;
BEGIN
tableObject := t_futureValues();
lastRowMinus0Value := 3;
lastRowMinus1Value := 6;
lastRowMinus2Value := 9;
lastRowMinus3Value := 12;
lastRowMinus4Value := 14;
lastRowMinus5Value := 20;
lastRowMinus6Value := 60;
avgDiff := (lastRowMinus5Value - lastRowMinus6Value) + avgDiff;
avgDiff := (lastRowMinus4Value - lastRowMinus5Value) + avgDiff;
avgDiff := (lastRowMinus3Value - lastRowMinus4Value) + avgDiff;
avgDiff := (lastRowMinus2Value - lastRowMinus3Value) + avgDiff;
avgDiff := (lastRowMinus1Value - lastRowMinus2Value) + avgDiff;
avgDiff := (lastRowMinus0Value - lastRowMinus1Value) + avgDiff;
avgDiff := avgDiff / 6;
predictedValue := avgDiff + lastRowMinus0Value;
begin
for i in 2..13 loop
predictedValue := predictedValue + avgDiff;
IF predictedValue < 0 THEN
predictedValue := 0;
END IF;
tableobject.extend();
tableobject(tableobject.count).futureValues := predictedValue;
-- insert into tableObject(futureValues)
-- values(predictedValue);
end loop;
end;
RETURN (tableObject);
END;