PL sql to find a string in a list - sql

Question

I have a problem because in this code I don't know how I can to test if a string is in a list which isn't initialized .
The code is this :
TYPE t1 IS TABLE OF VARCHAR2(32767) index by PLS_INTEGER;
v_t1 t1;
WOUT varchar2(80) :='bbbb';
v_t1(1):='bbbb';
if (WOUT member of v_t1 ) then
....
end if;
I don't know how i can write in plsql the condition that wout is inside v_t1 because member is accepted only with lists initialized.
Thanks for the help

Answer 1

With the collection declared as you have it there's no simple way to do what you're trying to do except to iterate through the collection to find the element you want:
declare
TYPE t1 IS TABLE OF VARCHAR2(32767)
index by PLS_INTEGER;
v_t1 t1;
WOUT VARCHAR2(80) := 'zzzz';
i NUMBER;
bFound BOOLEAN := FALSE;
BEGIN
v_t1(0) := 'aaaa';
v_t1(1) := 'bbbb';
v_t1(2) := 'cccc';
v_t1(26) := 'zzzz';
i := v_t1.FIRST;
LOOP
DBMS_OUTPUT.PUT_LINE('i=' || i);
IF v_t1(i) = WOUT THEN
bFound := TRUE;
EXIT;
END IF;
i := v_t1.NEXT(i);
IF i IS NULL THEN
EXIT;
END IF;
END LOOP;
DBMS_OUTPUT.PUT_LINE('bFound=' || CASE WHEN bFOUND THEN 'TRUE' ELSE 'FALSE' END);
end;
HOWEVER - if you change the collection so that it's indexed by the string it contains you can accomplish this task a bit easier by using the EXISTS collection method:
declare
TYPE T2 IS TABLE OF VARCHAR2(32767)
INDEX BY VARCHAR2(32767);
v_t2 t2;
WOUT VARCHAR2(80) := 'zzzz';
i NUMBER;
bFound BOOLEAN;
BEGIN
v_t2('aaaa') := 'aaaa';
v_t2('bbbb') := 'bbbb';
v_t2('cccc') := 'cccc';
v_t2('zzzz') := 'zzzz';
bFound := v_t2.EXISTS(WOUT);
DBMS_OUTPUT.PUT_LINE('bFound=' || CASE WHEN bFOUND THEN 'TRUE' ELSE 'FALSE' END);
END;
The documentation on collection methods can be found here.
Share and enjoy.

Answer 2

You can create special function that checks if such value is inside collection. Something like that:
FUNCTION exist_in_collection( p_table t1, p_text VARCHAR2) RETURN boolean
IS
BEGIN
IF p_table.LAST IS NULL THEN
RETURN FALSE;
ELSE
FOR i IN p_table.FIRST.. p_table.LAST
LOOP
IF p_table(i) = p_text THEN
RETURN TRUE;
END IF;
END LOOP;
RETURN FALSE;
END IF;
END exist_in_collection;
if p_table is not initialized LAST is NULL you will get FALSE. And then you can use this function to check whether the string is inside collection:
IF exist_in_collection(p_table, WOUT) THEN ... END IF;