Selecting conditions dynamically In oracle - oracle

Question

Hi What I would like to do is take the search criterias as parameters to my function and search through the table depending on the input parameters.. for example: IF ALL the parameters are NULL then the function will return evey field in the table, if a parameter is not NULL that parameter will be a search criteria. I could do an If statement but it would be too long and assuming that I would have had a bigger table it would be very painful, Is there any way I could accomplish this Task? Thanks
My Code:
create or replace type ordersinf as object(orderDate DATE, orderName VARCHAR2(20), orderPrice NUMBER)
create or replace type orders_tab IS TABLE OF ordersinf
and My Code is:
create or replace function execImmFunc(orderDate DATE, orderName in
VARCHAR2, orderPrice in NUMBER) return orders_tab is
Result orders_tab := orders_tab();
begin
SELECT ordersinf(orderDate => orders_Orderdate, orderName => orderName,orderPrice => orders_price)
BULK COLLECT INTO RESULT
FROM orders_table
WHERE orders_Orderdate >= orderDate OR orders_name = orderName OR orders_price = orderPrice ;
return(Result);
end execImmFunc;

Answer 1

Something like this:
CREATE OR REPLACE FUNCTION execImmFunc(
orderDate IN DATE,
orderName IN VARCHAR2,
orderPrice IN NUMBER
) RETURN orders_tab
IS
Result orders_tab;
BEGIN
SELECT ordersinf(
orderDate => orders_OrderDate,
orderName => orders_Name,
orderPrice => orders_price
)
BULK COLLECT INTO Result
FROM orders_table
WHERE ( orderDate IS NULL OR orders_OrderDate >= orderDate )
AND ( orderName IS NULL OR orders_name = orderName )
AND ( orderPrice IS NULL OR orders_price = orderPrice );
RETURN Result;
END execImmFunc;

Answer 2

Is this what you mean
WHERE (orderDate is null OR orders_Orderdate >= orderDate) AND (orderName is null OR orders_name = orderName) AND (orderPrice is null OR orders_price = orderPrice );
If a parameter orderDate is null - the clause passes and is effectively ignored?

Answer 3

Hey I dont have workspace with me but below is a very simple snippet
which can be used for dynamic sql formation as per the input provided.
Hope this helps
SET SERVEROUTPUT ON;
DECLARE
lv_col1 VARCHAR2(100):=123;
lv_col2 VARCHAR2(100):=1;
lv_col3 VARCHAR2(100):=NULL;
lv_col4 VARCHAR2(100):=45;
lv_col5 VARCHAR2(100):=8;
lv_sql LONG;
lv_where LONG;
BEGIN
lv_sql:='SELECT * FROM TABLE WHERE 1 = 1 ';
SELECT DECODE(lv_col1,NULL,'',' AND col1 = '''
||lv_col1
||'''')
|| DECODE(lv_col2,NULL,'',' AND col2 = '''
||lv_col2
||'''')
|| DECODE(lv_col3,NULL,'',' AND col3 = '''
||lv_col3
||'''')
|| DECODE(lv_col4,NULL,'',' AND col4 = '''
||lv_col4
||'''')
|| DECODE(lv_col5,NULL,'',' AND col5 = '''
||lv_col5
||'''')
INTO lv_where
FROM dual;
dbms_output.put_line(lv_sql||lv_where);
END;

Answer 4

Are you trying to set up so a parameter is either returned in the resultset or used in the where-clause? It does not look like you do, but rather you want to return all columns and use parameters in where only when they are not null.
If so, why not just a classic nvl-setup?
SELECT ordersinf(orderDate => orders_Orderdate
,orderName => orderName
,orderPrice => orders_price)
BULK COLLECT INTO RESULT
FROM orders_table
WHERE orders_Orderdate >= nvl(orderDate, orders_Orderdate)
OR orders_name = nvl(orderName, orders_name)
OR orders_price = nvl(orderPrice, orders_price);
I imagine those ORs ought to be AND as you probably want all conditions sent in to be true, but that is purely a desugn/requirement issue.