为什么这个 PL/SQL 函数不能编译？

Question

我正在学习 Oracle Apex、Oracle SQL 和 PL/SQL，我目前正在学习函数。我编写了一个函数，其中创建了一个表，存储了数据并将表返回给调用查询。问题是代码无法编译。我看不出问题出在哪里，我已经将代码与包括该站点在内的各种在线资源进行了比较。在我看来一切都很好，所以答案对我来说并不明显。

这是我写的代码：

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;

我得到的错误信息是：

ORA-06545：PL/SQL：编译错误 - 编译中止 ORA-06550：第 6 行，第 1 列：PLS-00103：遇到符号“CREATE” ORA-06550：第 0 行，第 0 列：PLS -00565: T_TABLE 必须作为潜在的 REF 目标（对象类型）完成

我毫不怀疑问题很简单，所以如果有人知道，我将不胜感激。

Answer 1

我不经常使用类型，但您的插入尝试插入到数组中。表必须是插入的目标。

使用以下代码：

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;