ora-06502

今天使用到動態的sql：
用的方法是：
用if else 拼出sql文，然後用
“open cursor for sql”來執行。
-- 大概代碼如下
create or replace....
is
    var_sql    varchar2(4000);
    TYPE typCur IS REF CURSOR;
    cur typCur;
    rec aType.aRecord%type;       -- aRecord是一個record
begin
    var_sql := '';
    if...then
        var_sql :=var_sql|| 'select a, b, c'..||..||..;
    elsif... then
        var_sql :=var_sql||..||..||..;
    end if;
   
    if...then
        var_sql := var_sql||'..';
    end if;
   
    open cur for var_sql
        loop fetch cur into rec
        exit when cur%notfound;
        ...
    end loop;
    close cur;
exception
    when others then
        close cur;
end;
/*
* 1. 由於拼的東西sql文太長，當我將拼好的var_sql塞給var_sql時，會報06502的錯，如果定義時將var_sql定義爲varchar2(32000)
*     【oracle db裏面varchar2最長爲4000bytes，而plsql在處理時，能處理的最長的是32000bytes】
*2. 1的問題完了之後，程序能執行到“fetch cur into rec”，rec在定義的時候定義的type與select檢索到的不一致，比如是b,a,c
*/




ORA-06502 PL/SQL: numeric or value error string

    Cause: An arithmetic, numeric, string, conversion, or constraint error occurred. For example, this error occurs if an attempt is made to assign the value NULL to a variable declared NOT NULL, or if an attempt is made to assign an integer larger than 99 to a variable declared NUMBER(2).

    Action: Change the data, how it is manipulated, or how it is declared so that values do not violate constraints.