oracle定义了两个自定义类型，一个split函数，array只能自定义，几百个包依赖这个自定义array，所以屏蔽了达梦的array关键字。

自定义类型：

CREATE OR REPLACE  TYPE "TY_STR_SPLIT"  is table of varchar2 (4000);

CREATE OR REPLACE  TYPE "ARRAY"  is VARRAY(4000) OF VARCHAR2(8000);
-- 跟ARRAY结构一样，就是名称不同
CREATE OR REPLACE  TYPE "ARR"  is VARRAY(4000) OF VARCHAR2(8000);

分词函数

Create or Replace 
function "SPLIT" (p_str in varchar2, 
                         p_delimiter in varchar2)
    return ty_str_split
is
    j      int := 0;
    i      int := 0;
    getLen int :=0;
    len    int := 0;
    len1   int := 0;
    str    varchar2 (4000);
    str_split ty_str_split := ty_str_split ();
    v_isFound number       :=0;
begin
    if p_delimiter is not null then
        select instr(p_str,p_delimiter) into v_isFound from dual;
         
        if v_isFound=0 then--没找到
            str_split.extend;
            str_split (str_split.count) := p_str;
        else
            len  := length (p_str);
            len1 := length (p_delimiter);
            while j <= len
            loop
                i     :=i+1;
                j     := instr (p_str, p_delimiter,i);
                getLen:=j-i;
                if j = 0 then
                    str := substr (p_str, i);
                    str_split.extend;
                    str_split (str_split.count) := str;
                    exit;
                else
                    str := substr (p_str, i, getLen);
                    str_split.extend;
                    str_split (str_split.count) := str;
                    i                           := j-1 + len1;
                end if;
            end loop;
        end if ;
    else
        str_split.extend;
        str_split (str_split.count) := p_str;
    end if ;
    return str_split;
end split;

TY_STR_SPLIT转arr函数

CREATE OR REPLACE  FUNCTION "TY_STR_SPLIT_TO_ARR" (srcType TY_STR_SPLIT)
RETURN ARR
AS
	/*变量说明部分*/
	newType ARR;
BEGIN
	newType:= NEW ARR();
	/*执行体*/
	for i in 1..srcType.count LOOP
		newType.EXTEND;
		newType(i) := srcType(i);
	end loop;
	return newType;
END;

测试：

SELECT TY_STR_SPLIT_TO_ARR(SPLIT('a,b,c',','))

能够让达梦支持说cast(TY_STR_SPLIT as ARR),底层逻辑自动调用的是上面的TY_STR_SPLIT_TO_ARR函数么？

上面的TY_STR_SPLIT_TO_ARR函数，返回值是ARR，编译成功。但是一旦类型改成ARRAY就编译失败了，这个即使屏蔽了关键词ARRAY，也没办法让编译通过么？