I've got a table A with 3 columns that contains the same data, for exemple:
TABLE A
KEY COL1 COL2 COL3
1 A B C
2 B C null
3 A null null
4 D E F
5 null C B
6 B C A
7 D E F
As a result I expect the distinct values of this table and the order doesn't matter. So key 1 and 6 are the same and 2 and 5 also and 4 and 7. The rest is different.
Ofcourse, I can't use a distinct in my select that will only filter 4 and 7.
I could use a very complex case statement, or a select in a select with an order by. But this needs to be used in a conversion, so performance is an issue here.
Does anyone have a good performant way to do this?
The result I expect
COL1 COL2 COL3
A B C
B C null
A null null
D E F
If you can have many columns then you can UNPIVOT then order the values and then PIVOT and take the DISTINCT rows:
Oracle Setup:
CREATE TABLE table_name ( KEY, COL1, COL2, COL3 ) AS
SELECT 1, 'A', 'B', 'C' FROM DUAL UNION ALL
SELECT 2, 'B', 'C', null FROM DUAL UNION ALL
SELECT 3, 'A', null, null FROM DUAL UNION ALL
SELECT 4, 'D', 'E', 'F' FROM DUAL UNION ALL
SELECT 5, null, 'C', 'B' FROM DUAL UNION ALL
SELECT 6, 'B', 'C', 'A' FROM DUAL UNION ALL
SELECT 7, 'D', 'E', 'F' FROM DUAL
Query:
SELECT DISTINCT
COL1, COL2, COL3
FROM (
SELECT key,
value,
ROW_NUMBER() OVER ( PARTITION BY key ORDER BY value ) AS rn
FROM table_name
UNPIVOT ( value FOR name IN ( COL1, COL2, COL3 ) ) u
)
PIVOT ( MAX( value ) FOR rn IN (
1 AS COL1,
2 AS COL2,
3 AS COL3
) )
Output:
COL1 | COL2 | COL3
:--- | :--- | :---
A | B | C
B | C | null
D | E | F
A | null | null
db<>fiddle here
The complicated case expression is going to have the best performance. But the simplest method is going to be conditional aggregation:
select key,
max(case when seqnum = 1 then col end) as col1,
max(case when seqnum = 2 then col end) as col2,
max(case when seqnum = 3 then col end) as col3
from (select key,col,
row_number() over (partition by key order by col asc) as seqnum
from ((select key, col1 as col from t) union all
(select key, col2 as col from t) union all
(select key, col3 as col from t)
) kc
where col is not null
) kc
group by key;
Related
I have this table
COL1 COL2
---------
A 1
B 5
C 12
D 14
And I would like to obtain this other one. This is, until the next col2 for each col1 is reached, a row with the COL1 and incremental values.
COL1 COL2
---------
A 1
A 2
A 3
A 4
B 5
B 6
B 7
B 8
B 9
B 10
B 11
C 12
C 13
D 14
EDIT: this is what I've tried so far. It seems I'm not far away from the solution but struggling to progress further than this.
WITH aux (
col1,
col2
) AS (
SELECT
'A',
1
FROM
dual
UNION ALL
SELECT
'B',
5
FROM
dual
UNION ALL
SELECT
'C',
12
FROM
dual
UNION ALL
SELECT
'D',
14
FROM
dual
), aux1 AS (
SELECT
a.*,
nvl(LEAD(a.col2) OVER(
ORDER BY
a.col2
), a.col2) h
FROM
aux a
)
SELECT
*
FROM
aux1
CONNECT BY level >= col2
AND level <= h;
testseq is the table containing your initial 4 rows. Use lead to find the stop value for col2 for each col1, and recursion to iterate and create the additional rows.
WITH xrows (col1, col2, lastcol2) AS (
SELECT t.*, LEAD(col2) OVER (ORDER BY col1) - 1
FROM testseq t
UNION ALL
SELECT col1, col2+1, lastcol2
FROM xrows t
WHERE col2 < lastcol2
)
SELECT col1, col2
FROM xrows
ORDER BY col1, col2
;
First you need to find the "next" number (whatever ordering you prefer) and then generate such number of rows with recursive subquery:
with a(code, num) as(
select 'A', 1 from dual union all
select 'B', 5 from dual union all
select 'C', 12 from dual union all
select 'D', 14 from dual
)
, b as (
select
a.*
, lead(num - 1, 1, num) over(order by code asc) as next_num
from a
)
select
b.code
, gen.val
from b
cross join lateral(
select num + level - 1 as val
from dual
connect by num + level - 1 <= next_num
) gen
order by 2 asc
Or if you prefer recursive CTE:
with a(code, num) as(
select 'A', 1 from dual union all
select 'B', 5 from dual union all
select 'C', 12 from dual union all
select 'D', 14 from dual
)
, b(code, next_num, val) as (
select
a.code
, lead(num - 1, 1, num) over(order by code asc) as next_num
, num
from a
union all
select
code
, next_num
, val + 1
from b
where val < next_num
)
select
b.code
, val
from b
order by 2 asc
CODE
VAL
A
1
A
2
A
3
A
4
B
5
B
6
B
7
B
8
B
9
B
10
B
11
C
12
C
13
D
14
livesql demo
How to achieve the below??
Anyone help me out
col_1 col_2
A 1
B 1
C 1
B 2
C 4
A 2
A 6
Output:
A B C
1 1 1
2 2 4
6
This will do the job, but it seems like quite an odd thing to want to do, so I am probably missing something?
CREATE TABLE #table (col1 CHAR(1), col2 INT);
INSERT INTO #table SELECT 'A', 1;
INSERT INTO #table SELECT 'B', 1;
INSERT INTO #table SELECT 'C', 1;
INSERT INTO #table SELECT 'B', 2;
INSERT INTO #table SELECT 'C', 4;
INSERT INTO #table SELECT 'A', 2;
INSERT INTO #table SELECT 'A', 6;
WITH Ranked AS (
SELECT
*,
ROW_NUMBER() OVER (PARTITION BY col1 ORDER BY col2) AS rank_id
FROM
#table),
Numbers AS (
SELECT 1 AS number
UNION ALL
SELECT number + 1 FROM Numbers WHERE number < 50)
SELECT
MAX(CASE WHEN col1 = 'A' THEN col2 END) AS [A],
MAX(CASE WHEN col1 = 'B' THEN col2 END) AS [B],
MAX(CASE WHEN col1 = 'C' THEN col2 END) AS [C]
FROM
Numbers n
INNER JOIN Ranked r ON r.rank_id = n.number
GROUP BY
n.number;
Results are:
A B C
1 1 1
2 2 4
6 NULL NULL
Looks like you are trying to pivot without aggregation? Here is another option:
select A, B, C from
( select col1, col2, dense_rank() over (partition by col1 order by col2) dr from #table) t
pivot
( max(t.col2) for t.col1 in (A, B, C)) pvt;
Also check this out for more examples/discussion: TSQL Pivot without aggregate function
According to some weird requirement, i need to select the record where all the output values in both the columns should be unique.
Input looks like this:
col1 col2
1 x
1 y
2 x
2 y
3 x
3 y
3 z
Expected Output is:
col1 col2
1 x
2 y
3 z
or
col1 col2
1 y
2 x
3 z
I tried applying the distinct on 2 fields but that returns all the records as overall they are distinct on both the fields. What we want to do is that if any value is present in the col1, then it cannot be repeated in the col2.
Please let me know if this is even possible and if yes, how to go about it.
Great problem! Armunin has picked up on the deeper structural issue here, this is a recursive enumerable problem description and can only be resolved with a recursive solution - base relational operators (join/union/etc) are not going to get you there. As Armunin cited, one approach is to bring out the PL/SQL, and though I haven't checked it in detail, I'd assume the PL/SQL code will work just fine. However, Oracle is kind enough to support recursive SQL, through which we can build the solution in just SQL:
-- Note - this SQL will generate every solution - you will need to filter for SOLUTION_NUMBER=1 at the end
with t as (
select 1 col1, 'x' col2 from dual union all
select 1 col1, 'y' col2 from dual union all
select 2 col1, 'x' col2 from dual union all
select 2 col1, 'y' col2 from dual union all
select 3 col1, 'x' col2 from dual union all
select 3 col1, 'y' col2 from dual union all
select 3 col1, 'z' col2 from dual
),
t0 as
(select t.*,
row_number() over (order by col1) id,
dense_rank() over (order by col2) c2_rnk
from t),
-- recursive step...
t1 (c2_rnk,ids, str) as
(-- base row
select c2_rnk, '('||id||')' ids, '('||col1||')' str
from t0
where c2_rnk=1
union all
-- induction
select t0.c2_rnk, ids||'('||t0.id||')' ids, str||','||'('||t0.col1||')'
from t1, t0
where t0.c2_rnk = t1.c2_rnk+1
and instr(t1.str,'('||t0.col1||')') =0
),
t2 as
(select t1.*,
rownum solution_number
from t1
where c2_rnk = (select max(c2_rnk) from t1)
)
select solution_number, col1, col2
from t0, t2
where instr(t2.ids,'('||t0.id||')') <> 0
order by 1,2,3
SOLUTION_NUMBER COL1 COL2
1 1 x
1 2 y
1 3 z
2 1 y
2 2 x
2 3 z
You can use a full outer join to merge two numbered lists together:
SELECT col1, col2
FROM ( SELECT col1, ROW_NUMBER() OVER ( ORDER BY col1 ) col1_num
FROM your_table
GROUP BY col1 )
FULL JOIN
( SELECT col2, ROW_NUMBER() OVER ( ORDER BY col2 ) col2_num
FROM your_table
GROUP BY col2 )
ON col1_num = col2_num
Change ORDER BY if you require a different order and use ORDER BY NULL if you're happy to let Oracle decide.
What would be the result if another row of
col1 value as 1 and col2 value as xx ?
A single row is better in this case:
SELECT DISTINCT TO_CHAR(col1) FROM your_table
UNION ALL
SELECT DISTINCT col2 FROM your_table;
My suggestion is something like this:
begin
EXECUTE IMMEDIATE 'CREATE global TEMPORARY TABLE tmp(col1 NUMBER, col2 VARCHAR2(50))';
end;
/
DECLARE
cur_print sys_refcursor;
col1 NUMBER;
col2 VARCHAR(50);
CURSOR cur_dist
IS
SELECT DISTINCT
col1
FROM
ttable;
filtered sys_refcursor;
BEGIN
FOR rec IN cur_dist
LOOP
INSERT INTO tmp
SELECT
col1,
col2
FROM
ttable t1
WHERE
t1.col1 = rec.col1
AND t1.col2 NOT IN
(
SELECT
tmp.col2
FROM
tmp
)
AND t1.col1 NOT IN
(
SELECT
tmp.col1
FROM
tmp
)
AND ROWNUM = 1;
END LOOP;
FOR rec in (select col1, col2 from tmp) LOOP
DBMS_OUTPUT.PUT_LINE('col1: ' || rec.col1 || '|| col2: ' || rec.col2);
END LOOP;
EXECUTE IMMEDIATE 'DROP TABLE tmp';
END;
/
May still need some refining, I am especially not happy with the ROWNUM = 1 part.
SQL Fiddle
Oracle 11g R2 Schema Setup:
CREATE TABLE tbl ( col1, col2 ) AS
SELECT 1, 'x' FROM DUAL
UNION ALL SELECT 1, 'y' FROM DUAL
UNION ALL SELECT 2, 'x' FROM DUAL
UNION ALL SELECT 2, 'y' FROM DUAL
UNION ALL SELECT 3, 'x' FROM DUAL
UNION ALL SELECT 3, 'y' FROM DUAL
UNION ALL SELECT 4, 'z' FROM DUAL;
Query 1:
WITH c1 AS (
SELECT DISTINCT
col1,
DENSE_RANK() OVER (ORDER BY col1) AS rank
FROM tbl
),
c2 AS (
SELECT DISTINCT
col2,
DENSE_RANK() OVER (ORDER BY col2) AS rank
FROM tbl
)
SELECT c1.col1,
c2.col2
FROM c1
FULL OUTER JOIN c2
ON ( c1.rank = c2.rank)
ORDER BY COALESCE( c1.rank, c2.rank)
Results:
| COL1 | COL2 |
|------|--------|
| 1 | x |
| 2 | y |
| 3 | z |
| 4 | (null) |
And to address the additional requirement:
What we want to do is that if any value is present in the col1, then it cannot be repeated in the col2.
Query 2:
WITH c1 AS (
SELECT DISTINCT
col1,
DENSE_RANK() OVER (ORDER BY col1) AS rank
FROM tbl
),
c2 AS (
SELECT DISTINCT
col2,
DENSE_RANK() OVER (ORDER BY col2) AS rank
FROM tbl
WHERE col2 NOT IN ( SELECT TO_CHAR( col1 ) FROM c1 )
)
SELECT c1.col1,
c2.col2
FROM c1
FULL OUTER JOIN c2
ON ( c1.rank = c2.rank)
ORDER BY COALESCE( c1.rank, c2.rank)
Here is my sample table
Col1 Col2
A 1
B 1
A 1
B 2
C 3
I want to be able to select distinct records where all rows have the same value in Col1 and Col2. So my answer should be
Col1 Col2
A 1
C 3
I tried
SELECT Col1, Col2 FROM Table GROUP BY Col1, Col2
This gives me
Col1 Col2
A 1
B 1
B 2
C 3
which is not the result I am looking for. Any tips would be appreciated.
Try this out:
SELECT col1, MAX(col2) aCol2 FROM t
GROUP BY col1
HAVING COUNT(DISTINCT col2) = 1
Output:
| COL1 | ACOL2 |
|------|-------|
| A | 1 |
| C | 3 |
Fiddle here.
Basically, this makes sure that amount the different values for col2 are unique for a given col1.
Try this:
SELECT * FROM MYTABLE
GROUP BY Col1, Col2
HAVING COUNT(*)>1
For example SQLFiddle here
you can try either of the below -
select col1, col2 from
(
select 'A' Col1 , 1 Col2
from dual
union all
select 'B' , 1
from dual
union all
select 'A' ,1
from dual
union all
select 'B' ,2
from dual
)
group by col1, col2
having count(*) >1;
OR
select col1, col2
from
(
select col1, col2, row_number() over (partition by col1, col2 order by col1, col2) cnt
from
(
select 'A' Col1 , 1 Col2
from dual
union all
select 'B' , 1
from dual
union all
select 'A' ,1
from dual
union all
select 'B' ,2
from dual
)
)
where cnt>1;
I have two rows from a table that has many columns. How do I return only those columns where the value for row1 does not equal the value for row2?
I'm using Oracle 11.1.0.07
~~ Edit: clarification ~~
Example:
So I've got a table with rows:
1 a b c d e f g h i j k l
2 a x c d e x g h y j k l
3 a b x d e x g h x y k z
I want to return rows where id (first column) is 1 or 3, only those columns that are different. So:
1 c f i j l
3 x x x y z
with column names.
In reality, the table I'm pulling from has 223007 rows, and 40 columns. The above is a simplified example. There are two rows (one each for primary key values) that I'm wanting to compare.
First, the SQL language was not designed for dynamic column generation. For that, you need to write dynamic SQL which should be done in a middle-tier or reporting component.
Second, if what you seek is to compare two specific rows, then the simplest solution would probably be to return those rows and analyze them in a middle-tier component. However, if you accept that we must return all columns and you insist on doing this in SQL, this is one solution:
With Inputs As
(
Select 1 As Col1,'a' As Col2,'b' As Col3,'c' As Col4,'d' As Col5,'e' As Col6,'f' As Col7,'g' As Col8,'h' As Col9,'i' As Col10,'j' As Col11,'k' As Col12,'l' As Col13
Union All Select 2,'a','x','c','d','e','x','g','h','y','j','k','l'
Union All Select 3,'a','b','x','d','e','x','g','h','x','y','k','z'
)
, TransposedInputs As
(
Select Col1, 2 As ColNum, Col2 As Value From Inputs
Union All Select Col1, 3, Col3 From Inputs
Union All Select Col1, 4, Col4 From Inputs
Union All Select Col1, 5, Col5 From Inputs
Union All Select Col1, 6, Col6 From Inputs
Union All Select Col1, 7, Col7 From Inputs
Union All Select Col1, 8, Col8 From Inputs
Union All Select Col1, 9, Col9 From Inputs
Union All Select Col1, 10, Col10 From Inputs
Union All Select Col1, 11, Col11 From Inputs
Union All Select Col1, 12, Col12 From Inputs
Union All Select Col1, 13, Col13 From Inputs
)
, UniqueValues As
(
Select Min(Col1) As Col1, ColNum, Value
From TransposedInputs
Where Col1 In(1,3)
Group By ColNum, Value
Having Count(*) = 1
)
Select Col1
, Min( Case When ColNum = 2 Then Value End ) As Col2
, Min( Case When ColNum = 3 Then Value End ) As Col3
, Min( Case When ColNum = 4 Then Value End ) As Col4
, Min( Case When ColNum = 5 Then Value End ) As Col5
, Min( Case When ColNum = 6 Then Value End ) As Col6
, Min( Case When ColNum = 7 Then Value End ) As Col7
, Min( Case When ColNum = 8 Then Value End ) As Col8
, Min( Case When ColNum = 9 Then Value End ) As Col9
, Min( Case When ColNum = 10 Then Value End ) As Col10
, Min( Case When ColNum = 11 Then Value End ) As Col11
, Min( Case When ColNum = 12 Then Value End ) As Col12
, Min( Case When ColNum = 13 Then Value End ) As Col13
From UniqueValues
Group By Col1
Results:
Col1 | Col2 | Col3 | Col4 | Col5 | Col6 | Col7 | Col8 | Col9 | Col10 | Col11 | Col12 | Col13
1 | NULL | NULL | c | NULL | NULL | f | NULL | NULL | i | j | NULL | l
3 | NULL | NULL | x | NULL | NULL | x | NULL | NULL | x | y | NULL | z
If you're trying to transpose or pivot your row1 and row2 into columns, then these questions might help you:
Oracle PIVOT, twice?
Oracle SQL pivot query
etc (Google for Oracle PIVOT Query)
After pivoting, you can select only those tuples that have row1_pivoted <> row2_pivoted
Hmm. first stab at an answer was wrong when I re-read the question. So... for clarification, you've got some rows/values
a b c
d e f
a b c
and you'd like only the 'd e f' row returned, because it doesn't have a duplicate row elsewhere?
The number of columns in the result set can't be dynamic (without resorting to dynamic SQL).
You might be interested in the Unpivot operator. That would let you return the columns as rows.
I haven't experiemented with it myself yet, so unfortunately I'm unable to help you with it :/
Edit
I wanted to give manual pivoting a shot :)
select *
from inputs;
ID C1 C2 C3 C4 C5 C6
--- -- -- -- -- -- --
1 a b c d e f
2 a x c d e x
3 a b x d e x
with unpivoted as(
select id, 'c1' as cn, c1 as cv from inputs union all
select id, 'c2' as cn, c2 as cv from inputs union all
select id, 'c3' as cn, c3 as cv from inputs union all
select id, 'c4' as cn, c4 as cv from inputs union all
select id, 'c5' as cn, c5 as cv from inputs union all
select id, 'c6' as cn, c6 as cv from inputs
)
select cn
,max(case when id = 1 then cv end) as id1
,max(case when id = 3 then cv end) as id3
from unpivoted
where id in(1,3)
group
by cn
having count(distinct cv) = 2;
CN ID1 ID3
-- --- ---
c3 c x
c6 f x
The above works by creating one row for each column and ID (2 * 6 = 12 rows).
Then I group by the column name (assigned as a literal).
I will always get 6 groups (one for each column). In each group I will have exactly two rows (one for each selected ID).
In the having clause, I count the number of unique values for the column. If the rows have the same value, then the numner of unique values = 1. Else we have a mismatch.
Note 1. id in(x,y) is pushed into the view, so we are not selecting the entire table.
Note 2. This cannot be extended into comparing more than 2 rows.
Note 3. This does not deal with NULLS in either column