Help with code

[Semei770]

I have this code in oracle
if (Income == "NULL") {0}
else if (Emplid == Prior(Emplid) && Income != Prior(Income)) {1}
else if (Emplid != Prior(Emplid) && Income != "Unreported") {1}
else {0}

I did this

 SELECT

    *,

  case

      WHEN Income = 'NULL' THEN 0

        WHEN LAG(Emplid) OVER (ORDER BY Emplid ASC, Term ASC) = Emplid AND LAG(Income) OVER (ORDER BY Emplid ASC, Term ASC) != IncomeYY THEN 1

        WHEN ROW_NUMBER() OVER (PARTITION BY  Emplid, Income ORDER BY Term ASC) = 1 THEN 1

        WHEN LAG(Emplid) OVER (ORDER BY Emplid ASC, Term ASC) != Emplid AND Income != 'Unreported' THEN 1

        ELSE 0

    END AS PREVIUOS_INCOME

    FROM

   Table
It does not work; I appreciate any advice.

[#2]

"Does not work" means what in detail? That's really to less on information.
Please post table design as DDL, some sample data as DML statement and the expected result.

[#3]

Thank you @olafhelper  

Here is an image about what result I need it

Emplid	Term	IncomeYY	Count_Income
1	2213	Unreported	0
1	2237	$35,000 or More	1
1	2237	$35,000 or More	0
1	2243	Unreported	0
1	2243	$35,000 or More	1
1	2245	Unreported	0

[#4]

---

Here is an image about what result I need it

 Fine,m and what is the source data?

Again, please post table design as DDL, some sample data as DML statement and the expected result.