Passing an array to function and use it in WHERE IN clause - arrays

Question

I want to use array(which is passed to function) under Where in clause
Here is what i tried
First created the array type
create or replace type p_emp_arr as table of number
Function is
create or replace
FUNCTION getEmployee_func ( empId_arr IN p_emp_arr)
RETURN number IS
total number(2) := 0;
BEGIN
IF(empId_arr is null)
THEN
empIdClause := '';
ELSE
empIdClause := 'AND Employee.empId in (select column_value from table('||empId_arr||'))';
END IF;
....
RETURN total;
END;
But gives error
Error(17,23): PLS-00306: wrong number or types of arguments in call to '||'

Answer 1

The error is because CONCAT (||) operator accepts only scalar variables (string/number), you cannot pass an array to it.
You need to execute this as a dynamic PL/SQL block.
In case you want to bind the array dynamically, try something like this.
Bind the variables using IN and OUT keywords appropriately.
In your Anonymous block string, prefix the to-be-bind variables with colon (:)
EXECUTE IMMEDIATE '
BEGIN
SELECT
COLUM1,COLUMN2..
INTO
:VAR1, :VAR2..
FROM .... WHERE...
AND Employee.empId in (select column_value from table(:empId_arr));
END;
'
USING OUT VAR1, OUT VAR2... IN empId_arr;
It can also be Simply,
OPEN EMP_CURSOR FOR
'SELECT * FROM Employee
where empId in SELECT COLUMN_VALUE FROM TABLE(:empId_arr)'
USING empId_arr ;
If you take the output as a cursor;
AS Wernfried mentioned.. Using MEMBER OF operator.
OPEN EMP_CURSOR FOR
'SELECT * FROM Employee
where empId member of :empId_arr'
USING empId_arr ;