select first 10 rows, then decide which rows to include afterwards - sql

Question

I have 2 columns in table. The 1st column represents the name of different companies and the 2nd column displays the count of products.
COL 1 COL 2
CompA 2323
CompB 2320
CompC 1999
CompD 1598
CompE 1400...so on
What i want to do is to display first 10 rows showing first 10 companies name and its count in desc order.
Then I want to compare 10th company count with 11th company count. If they match, then display 11th company name and its count. If 10th company count doesn't match 11th company count, then display first 10 records only.
I have read only access so I can't update or insert new records in table.
How can this be done?

Answer 1

If what you want to do is display the top ten counts, including ties. This is simple to solve with an ANALYTIC function such as RANK() or DENSE_RANK() ...
SQL> select * from
2 ( select
3 ename
4 , sal
5 , rank() over (order by sal desc) sal_rank
6 from emp
7 )
8 where sal_rank <= 10
9 /
ENAME SAL SAL_RANK
---------- ---------- ----------
QUASSNOI 6500 1
SCHNEIDER 5000 2
FEUERSTEIN 4500 3
VERREYNNE 4000 4
LIRA 3750 5
PODER 3750 5
KESTELYN 3500 7
TRICHLER 3500 7
GASPAROTTO 3000 9
ROBERTSON 2990 10
RIGBY 2990 10
11 rows selected.
SQL>
Note that if RIGBY had had the same salary as GASPAROTTO, their SAL_RANK would have been 9, ROBERTSON's would have been 11 and the result set would have comprised ten rows.
DENSE_RANK() differs from RANK() in that it always returns the top ten whatevers, instead of skipping ties...
SQL> select * from
2 ( select
3 ename
4 , sal
5 , dense_rank() over (order by sal desc) sal_rank
6 from emp
7 )
8 where sal_rank <= 10
9 /
ENAME SAL SAL_RANK
---------- ---------- ----------
1
SCHNEIDER 5000 2
FEUERSTEIN 4500 3
VERREYNNE 4000 4
LIRA 3750 5
PODER 3750 5
KESTELYN 3500 6
TRICHLER 3500 6
GASPAROTTO 3000 7
ROBERTSON 2990 8
RIGBY 2990 8
SPENCER 2850 9
BOEHMER 2450 10
13 rows selected.
SQL>

Answer 2

Try this:
SELECT col1, col2
FROM (
SELECT col1, col2
FROM Table
WHERE col2 >= (SELECT col2
FROM (SELECT col2 FROM Table ORDER BY col2 DESC) t1
WHERE t1.ROWNUM = 10)
ORDER BY col2 DESC) t2
WHERE t2.ROWNUM <= 11

Answer 3

With Top10Co As
(
Select Col1 As CompanyName, Col2 As Cnt
, Row_Number() Over ( Order By Col2 Desc ) As Num
From MyTable
)
Select CompanyName, Cnt
From Top10Co
Where Num <= 10
Union All
Select Col1, Col2
From MyTable
Where Exists (
Select 1
From Top10Co As T2
Where T2.Num = 10
And T2.CompanyName <> MyTable.Col1
And T2.Cnt = MyTable.Col2
)

Answer 4

I think that what you are saying can be done by writing a pl/sql block of code of top-n query.
some thing like this would help
decalre
v_col_1 companies.col_1%TYPE;
v_col_2 companies.col_2%TYPE;
count number;
col_2_all number;
CURSOR companies is SELECT *
FROM (select * from companies ORDER BY col_2)
WHERE rownum <= 10
ORDER BY rownum;
begin
loop
fetch companies into v_cal_1,v_col_2;
count++;
if count =10 then
col_2_all=v_col_2
dbms_output.put_line('company name'||v_cal_1||'company count'||v_cal_2);
elsif count =11 then
if col_2_all=v_col_2 then
dbms_output.put_line('company name'||v_cal_1||'company count'||v_cal_2);
end if;
end if;
EXIT WHEN count>11;
end;
i am not sure about the syntax but it has to be something like this :)