Oracle使用由字串索引的二維陣列

–參考文章：http://www.oracle.com/technetwork/issue-archive/2014/14-sep/o54plsql-2245345.html
–SAMPLE DATA
店名 商品 銷量
A APPLE 3000
A BANANA 2000
B APPLE 5000
B MELON 100

–CONSTRUCT PACKAGE
CREATE OR REPLACE PACKAGE p_nested_array IS
SUBTYPE prod_name IS VARCHAR2(200);
SUBTYPE store_name IS VARCHAR2(200);
c_was_processed CONSTANT BOOLEAN := TRUE;

TYPE t_prod_qty IS TABLE OF NUMBER(10) INDEX BY prod_name;
TYPE t_store_prod_qty IS TABLE OF t_prod_qty INDEX BY store_name;
store_prod_qty_t t_store_prod_qty;

PROCEDURE reset_store_prod_qty;
FUNCTION already_store_prod(store_name_in VARCHAR2,
prod_name_in VARCHAR2) RETURN BOOLEAN;
PROCEDURE add_store_prod_qty(store_name_in VARCHAR2,
prod_name_in VARCHAR2,
qty_in NUMBER);
FUNCTION find_store_prod_qty(store_name_in VARCHAR2,
prod_name_in VARCHAR2) RETURN NUMBER;
PROCEDURE print_store_prod_qty;
END p_nested_array;
/

CREATE OR REPLACE PACKAGE BODY p_nested_array IS
PROCEDURE reset_store_prod_qty IS
BEGIN
store_prod_qty_t.DELETE;
END reset_store_prod_qty;

FUNCTION already_store_prod(store_name_in VARCHAR2,
prod_name_in VARCHAR2) RETURN BOOLEAN IS

BEGIN
IF store_prod_qty_t(store_name_in) (prod_name_in) IS NOT NULL THEN
RETURN TRUE;
ELSE
RETURN FALSE;
END IF;
EXCEPTION
WHEN no_data_found THEN
RETURN FALSE;
END already_store_prod;

PROCEDURE add_store_prod_qty(store_name_in VARCHAR2,
prod_name_in VARCHAR2,
qty_in NUMBER) IS
BEGIN
store_prod_qty_t(store_name_in)(prod_name_in) := qty_in;
END add_store_prod_qty;

FUNCTION find_store_prod_qty(store_name_in VARCHAR2,
prod_name_in VARCHAR2) RETURN NUMBER IS
BEGIN
RETURN store_prod_qty_t(store_name_in)(prod_name_in);
EXCEPTION
WHEN no_data_found THEN
RETURN NULL;
END find_store_prod_qty;

PROCEDURE print_store_prod_qty IS
store_name_idx store_name;
prod_name_idx prod_name;
BEGIN
store_name_idx := store_prod_qty_t.FIRST;
dbms_output.put_line(‘store_name_idx: ’ || store_name_idx);
WHILE store_name_idx IS NOT NULL LOOP
prod_name_idx := store_prod_qty_t(store_name_idx).FIRST;
–(store_prod_qty_t(store_name_idx).FIRST);
WHILE prod_name_idx IS NOT NULL LOOP
dbms_output.put_line(store_name_idx || ‘–’ || prod_name_idx || ‘: ’ ||
store_prod_qty_t(store_name_idx) (prod_name_idx));
prod_name_idx := store_prod_qty_t(store_name_idx).NEXT(prod_name_idx);
–(store_prod_qty_t(store_name_idx).NEXT(prod_name_idx));
END LOOP;

  store_name_idx := store_prod_qty_t.NEXT(store_name_idx);
END LOOP;

/* error raised
  FOR i IN store_prod_qty_t.FIRST .. store_prod_qty_t.LAST LOOP
  FOR j IN store_prod_qty_t(i).FIRST .. store_prod_qty_t(i).LAST LOOP
    dbms_output.put_line('Store ' || i || ' saled ' || store_prod_qty_t(i)
                         (j) || ' ' || j || '.');
  END LOOP;
END LOOP;*/

END print_store_prod_qty;

END p_nested_array;
/

–TEST SCRIPT
DECLARE
BEGIN
P_NESTED_ARRAY.RESET_STORE_PROD_QTY;
P_NESTED_ARRAY.ADD_STORE_PROD_QTY(‘A’,’APPLE’,3000);
P_NESTED_ARRAY.ADD_STORE_PROD_QTY(‘A’,’BANANA’,2000);
P_NESTED_ARRAY.ADD_STORE_PROD_QTY(‘B’,’APPLE’,5000);

IF NOT P_NESTED_ARRAY.ALREADY_STORE_PROD(‘B’,’MELON’) THEN
P_NESTED_ARRAY.ADD_STORE_PROD_QTY(‘B’,’MELON’,100);
ELSE
DBMS_OUTPUT.PUT_LINE(‘Store B”s MELON saled ‘||P_NESTED_ARRAY.FIND_STORE_PROD_QTY(‘B’,’MELON’)||’.’);
END IF;

DBMS_OUTPUT.PUT_LINE(‘Store B”s MELON saled ‘||P_NESTED_ARRAY.FIND_STORE_PROD_QTY(‘B’,’MELON’)||’.’);

P_NESTED_ARRAY.print_store_prod_qty;

END;
/

–OUTPUT:
Store B’s MELON saled 100.
store_name_idx: A
A–APPLE: 3000
A–BANANA: 2000
B–APPLE: 5000
B–MELON: 100

—-Dylan Presents.