今天在網上看到了oracle cast的一個用法，做一記錄

【轉自：http://hi.baidu.com/wenwenxiaoxing/blog/item/419cd6ca91b01e43f21fe794.html】

今天在網上看了split函式及測試方法。split函式我以前就有了，但在測試此函式的方法中看到了cast，這個函式我從未用過。

CREATE OR REPLACE TYPE ty_str_split IS TABLE OF VARCHAR2 (4000); /

CREATE OR REPLACE FUNCTION fn_split (p_str IN VARCHAR2, p_delimiter IN VARCHAR2)
RETURN ty_str_split
IS
j INT := 0;
i INT := 1;
len INT := 0;
len1 INT := 0;
str VARCHAR2 (4000);
str_split ty_str_split := ty_str_split ();
BEGIN
len := LENGTH (p_str);
len1 := LENGTH (p_delimiter);

WHILE j < len
LOOP
j := INSTR (p_str, p_delimiter, i);

IF j = 0
THEN
j := len;
str := SUBSTR (p_str, i);
str_split.EXTEND;
str_split (str_split.COUNT) := str;

IF i >= len
THEN
EXIT;
END IF;
ELSE
str := SUBSTR (p_str, i, j - i);
i := j + len1;
str_split.EXTEND;
str_split (str_split.COUNT) := str;
END IF;
END LOOP;

RETURN str_split;
END fn_split;
/

--測試方法

DECLARE
CURSOR c
IS
SELECT *
FROM TABLE (CAST (fn_split ('123,,d', ',') AS ty_str_split
)
);

r c%ROWTYPE;
i integer :=0;
BEGIN
OPEN c;

LOOP
FETCH c INTO r;

EXIT WHEN c%NOTFOUND;
DBMS_OUTPUT.put_line (r.column_value);
i := i+1;

END LOOP;

CLOSE c;
DBMS_OUTPUT.put_line (i);
END;
/

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