Tricky count function query

Question

Hi All.
I was trying to write a query for below result set but can not figure out if i can achieve below result set through T-SQL.
Emplid FunctionId Count
1 2
1 3 1
1 4 2
1 4
1 5 3
1 6 4
1 3
2 3
2 3
2 1 1
2 2 2
Description
When an Employee is changing from job/function, am struggling to get incremental number / count for that employ based on no. of funtionid changed.
I need a count only when an employee is going to do something else (another function).
The example above is showing how the count output should be.
am not sure it i need to use any analytical function, any help would be appreciated.
and many thanks in advance for reading my question

Answer 1

Something like
SQL> ed
Wrote file afiedt.buf
  1  with x as (
  2    select 1 empid, 2 functionid, sysdate dt from dual union all
  3    select 1, 3, sysdate+1 from dual union all
  4    select 1, 4, sysdate+2 from dual union all
  5    select 1, 4, sysdate+3 from dual union all
  6    select 2, 3, sysdate+4 from dual union all
  7    select 2, 3, sysdate+5 from dual union all
  8    select 2, 1, sysdate+6 from dual
  9  )
10  select empid,
11         functionid,
12         sum(case when functionid = prior_functionid
13                  then 0
14                  else 1
15               end) over (partition by empid
16                              order by dt)-1 cnt
17    from (
18  select empid,
19         functionid,
20         lag(functionid) over (partition by empid
21                                   order by dt) prior_functionid,
22         dt
23    from x
24* )
SQL> /
     EMPID FUNCTIONID        CNT
         1          2          0
         1          3          1
         1          4          2
         1          4          2
         2          3          0
         2          3          0
         2          1          1
7 rows selected.appears to work
Justin