Pivot from row to column - Oracle SQL - sql

I have a table:
Table1
row_id var var_val
1 Test 1 123
1 Test 2 456
1 Test 3 789
1 Test 4 1234
2 Test 1 665t
2 Test 2 dsfs
2 Test 3 df
2 Test 4 sfd
3 Test 1 sfs
3 Test 2 sf
3 Test 3 sdfs
3 Test 4 sfsd
Here is the output:
Table2
row_id var1 var2
1 123 456
2 665t dsfs
3 sfs sf
For var1 - get value where var = "Test 1"
For var2 - get value where var = "Test 2"
Is there a way to use pivot or some way of extracting the variable for each row_id from the table1 as per above?

You can use conditional aggregation or a join:
select t11.row_id, t11.var, t12.var
from table1 t11 join
table1 t12
on t11.row_id = t12.row_id and
t11.var = 'Test 1' and
t12.var = 'Test 2'

Is there a way to use pivot...?
Sure:
select *
from table1
pivot (max(var_val) for var in ('Test 1' var1, 'Test 2' var2))
demo

You can use correlated subqueries and row_number() window analytic function together
with table1(row_id, var, var_val) as
(
select 1,'Test 1','123' from dual union all
select 1,'Test 2','456' from dual union all
select 1,'Test 3','789' from dual union all
select 1,'Test 4','1234' from dual union all
select 2,'Test 1','665t' from dual union all
select 2,'Test 2','dsfs' from dual union all
select 2,'Test 3','df' from dual union all
select 2,'Test 4','sfd' from dual union all
select 3,'Test 1','sfs' from dual union all
select 3,'Test 2','sf' from dual union all
select 3,'Test 3','sdfs' from dual union all
select 3,'Test 4','sfsd' from dual
), t2 as
(
select t.*, row_number() over (partition by var order by row_id) as rn
from table1 t
)
select distinct row_id,
(select var_val
from table1 t2
where t2.var = 'Test 1'
and t2.row_id = rn) as var1,
(select var_val
from table1 t2
where t2.var = 'Test 2'
and t2.row_id = rn) as var2
from t2
order by row_id
ROW_ID VAR1 VAR2
------ ---- ----
1 123 456
2 665t dsfs
3 sfs sf
Demo

Related

Find rows with consecutive ones

I've two integer columns and need to display the rows with consecutive one's in the NUM column.
Sample data:
CREATE TABLE table_name ( ID, NUM ) AS
SELECT 1, 1 FROM DUAL UNION ALL
SELECT 2, 1 FROM DUAL UNION ALL
SELECT 3, 1 FROM DUAL UNION ALL
SELECT 4, 2 FROM DUAL UNION ALL
SELECT 5, 1 FROM DUAL UNION ALL
SELECT 6, 2 FROM DUAL UNION ALL
SELECT 7, 2 FROM DUAL;
Expected Output:
ID NUM
-- ---
1 1
2 1
3 1
I have tried using self-joins and achieved the result:
WITH TAB (ID, NUM) AS
(
SELECT 1, 1 FROM DUAL UNION ALL
SELECT 2, 1 FROM DUAL UNION ALL
SELECT 3, 1 FROM DUAL UNION ALL
SELECT 4, 2 FROM DUAL UNION ALL
SELECT 5, 1 FROM DUAL UNION ALL
SELECT 6, 2 FROM DUAL UNION ALL
SELECT 7, 2 FROM DUAL
)
SELECT DISTINCT
T.ID,
T.NUM
FROM
TAB T
JOIN (
SELECT
T1.ID ID1,
T2.ID ID2,
T1.NUM,
COUNT(1) OVER(
PARTITION BY T1.NUM
) RN
FROM
TAB T1
JOIN TAB T2 ON ( T1.NUM = T2.NUM
AND T1.ID = T2.ID + 1 )
) T_IN ON ( ( T.ID = T_IN.ID1
OR T.ID = T_IN.ID2 )
AND T.NUM = T_IN.NUM
AND RN >= 2 ) -- THIS CONDITION IS TO RESTRICT CONSECUTIVES LESS THAN 3
ORDER BY
1
output:
db<>fiddle demo
Use analytic functions LAG or LEAD:
Oracle Setup:
CREATE TABLE table_name ( ID, NUM ) AS
SELECT 1, 1 FROM DUAL UNION ALL
SELECT 2, 1 FROM DUAL UNION ALL
SELECT 3, 1 FROM DUAL UNION ALL
SELECT 4, 2 FROM DUAL UNION ALL
SELECT 5, 1 FROM DUAL UNION ALL
SELECT 6, 2 FROM DUAL UNION ALL
SELECT 7, 2 FROM DUAL;
Query:
SELECT id,num
FROM (
SELECT id,
num,
LAG( num ) OVER ( ORDER BY id ) AS prev_num,
LEAD( num ) OVER ( ORDER BY id ) AS next_num
FROM table_name
)
WHERE num = 1
AND ( num = prev_num
OR num = next_num )
Output:
ID | NUM
-: | --:
1 | 1
2 | 1
3 | 1
db<>fiddle here

Identify only when value matches

I need to return only rows that have the match e.g Value = A, but I only need the rows that have A and with no other values.
T1:
ID Value
1 A
1 B
1 C
2 A
3 A
3 B
4 A
5 B
5 D
5 E
5 F
Desired Output:
2
4
how can I achieve this?
when I try the following, 1&3 are also returned:
select ID from T1 where Value ='A'
With NOT EXISTS:
select t.id
from tablename t
where t.value = 'A'
and not exists (
select 1 from tablename
where id = t.id and value <> 'A'
)
From the sample data you posted there is no need to use:
select distinct t.id
but if you get duplicates then use it.
Another way if there are no null values:
select id
from tablename
group by id
having sum(case when value <> 'A' then 1 else 0 end) = 0
Or if you want the rows where the id has only 1 value = 'A':
select id
from tablename
group by id
having count(*) = 1 and max(value) = 'A'
I think the simplest way is aggregation with having:
select id
from tablename
group by id
having min(value) = max(value) and
min(value) = 'A';
Note that this ignores NULL values so it could return ids with both NULL and A. If you want to avoid that:
select id
from tablename
group by id
having count(value) = count(*) and
min(value) = max(value) and
min(value) = 'A';
Oracle Setup:
CREATE TABLE test_data ( ID, Value ) AS
SELECT 1, 'A' FROM DUAL UNION ALL
SELECT 1, 'B' FROM DUAL UNION ALL
SELECT 1, 'C' FROM DUAL UNION ALL
SELECT 2, 'A' FROM DUAL UNION ALL
SELECT 3, 'A' FROM DUAL UNION ALL
SELECT 3, 'B' FROM DUAL UNION ALL
SELECT 4, 'A' FROM DUAL UNION ALL
SELECT 5, 'B' FROM DUAL UNION ALL
SELECT 5, 'D' FROM DUAL UNION ALL
SELECT 5, 'E' FROM DUAL UNION ALL
SELECT 5, 'F' FROM DUAL
Query:
SELECT ID
FROM test_data
GROUP BY ID
HAVING COUNT( CASE Value WHEN 'A' THEN 1 END ) = 1
AND COUNT( CASE Value WHEN 'A' THEN NULL ELSE 1 END ) = 0
Output:
| ID |
| -: |
| 2 |
| 4 |
db<>fiddle here

Cannot figure out logic to update a table

I have below table.
TABLE: ABCD
B column have value 1 whenever there is a change in A column. Now I have to update the table like below. How can I do that?
You can do this using a correlated subquery:
update t
set b = (select sum(t2.b) from t t2 where t2.A <= t.A);
This is standard SQL and should work in either Oracle or Teradata.
Lets have a slightly more complicated example (where the changes in B are not correlated to the changes in A):
Oracle Setup:
CREATE TABLE ABCD( A, B ) AS
SELECT 1, 0 FROM DUAL UNION ALL
SELECT 1, 0 FROM DUAL UNION ALL
SELECT 1, 1 FROM DUAL UNION ALL
SELECT 2, 1 FROM DUAL UNION ALL
SELECT 2, 0 FROM DUAL UNION ALL
SELECT 3, 0 FROM DUAL UNION ALL
SELECT 3, 1 FROM DUAL UNION ALL
SELECT 3, 0 FROM DUAL;
Update:
UPDATE ABCD t1
SET b = (
SELECT sm
FROM (
SELECT ROWID AS id,
SUM( b ) OVER ( ORDER BY a, ROWNUM ) AS sm
FROM ABCD
) t2
WHERE t1.ROWID = t2.ID
);
Output:
SELECT * FROM ABCD;
A B
- -
1 0
1 0
1 1
2 2
2 2
3 2
3 3
3 3
(Note: This is an Oracle solution; I have no idea if it will or won't work in Teradata.)

How to do select count(*) group by and select * at same time?

For example, I have table:
ID | Value
1 hi
1 yo
2 foo
2 bar
2 hehe
3 ha
6 gaga
I want my query to get ID, Value; meanwhile the returned set should be in the order of frequency count of each ID.
I tried the query below but don't know how to get the ID and Value column at the same time:
SELECT COUNT(*) FROM TABLE group by ID order by COUNT(*) desc;
The count number doesn't matter to me, I just need the data to be in such order.
Desire Result:
ID | Value
2 foo
2 bar
2 hehe
1 hi
1 yo
3 ha
6 gaga
As you can see because ID:2 appears most times(3 times), it's first on the list,
then ID:1(2 times) etc.
you can try this -
select id, value, count(*) over (partition by id) freq_count
from
(
select 2 as ID, 'foo' as value
from dual
union all
select 2, 'bar'
from dual
union all
select 2, 'hehe'
from dual
union all
select 1 , 'hi'
from dual
union all
select 1 , 'yo'
from dual
union all
select 3 , 'ha'
from dual
union all
select 6 , 'gaga'
from dual
)
order by 3 desc;
select t.id, t.value
from TABLE t
inner join
(
SELECT id, count(*) as cnt
FROM TABLE
group by ID
)
x on x.id = t.id
order by x.cnt desc
How about something like
SELECT t.ID,
t.Value,
c.Cnt
FROM TABLE t INNER JOIN
(
SELECT ID,
COUNT(*) Cnt
FROM TABLE
GROUP BY ID
) c ON t.ID = c.ID
ORDER BY c.Cnt DESC
SQL Fiddle DEMO
I see the question is already answered, but since the most obvious and most simple solution is missing, I'm posting it anyway. It doesn't use self joins nor subqueries:
SQL> create table t (id,value)
2 as
3 select 1, 'hi' from dual union all
4 select 1, 'yo' from dual union all
5 select 2, 'foo' from dual union all
6 select 2, 'bar' from dual union all
7 select 2, 'hehe' from dual union all
8 select 3, 'ha' from dual union all
9 select 6, 'gaga' from dual
10 /
Table created.
SQL> select id
2 , value
3 from t
4 order by count(*) over (partition by id) desc
5 /
ID VALU
---------- ----
2 bar
2 hehe
2 foo
1 yo
1 hi
6 gaga
3 ha
7 rows selected.

Oracle passing outer query value to inner query

This might be a simple but I need to apply the logic in other:
WITH t(col) AS (
SELECT 1 FROM dual
UNION SELECT 2 FROM dual
UNION SELECT 3 FROM dual
UNION SELECT 4 FROM dual
UNION SELECT 5 FROM dual
)
SELECT col , --- will works as usual
(SELECT col FROM t WHERE col = outer_q.col) new_col, --working as well
(
SELECT sum (latest_col)
from
(
SELECT col latest_col FROM t WHERE col = outer_q.col
UNION ALL
SELECT col FROM t WHERE col = outer_q.col
)
)newest_col -- need to get an output "4"
from t outer_q where col = 2;
An simple output like:
COL NEW_COL NEWEST_COL
---------- ---------- ----------
2 2 4
I just need to use the outer most value to the inner I used for the third column
EDITING-- sample with more data:
WITH
t(col) AS
( SELECT 1 FROM dual
UNION
SELECT 2 FROM dual
UNION
SELECT 3 FROM dual
UNION
SELECT 4 FROM dual
UNION
SELECT 5 FROM dual
),
t1(amount, col) AS
(SELECT 100 , 2 FROM dual
UNION
SELECT 200, 3 FROM dual
)
SELECT col,
(SELECT col FROM t WHERE col = outer_q.col
) new_col,
(SELECT SUM(x)
FROM
(SELECT col x FROM t
UNION ALL
SELECT amount x FROM t1
)
WHERE col = outer_q.col
) newest_col -- gives 315 as it takes whole `SUM`
FROM t outer_q
WHERE col = 2;
An output is expected like:
COL NEW_COL NEWEST_COL
---------- ---------- ----------
2 2 102
Thanks in advance for any help.
Well, you can if you refactor a but your query:
WITH t(col) AS (
SELECT 1 FROM dual
UNION SELECT 2 FROM dual
UNION SELECT 3 FROM dual
UNION SELECT 4 FROM dual
UNION SELECT 5 FROM dual
)
SELECT col,
(SELECT col FROM t WHERE col = outer_q.col) new_col,
(SELECT sum (latest_col)
from
(
SELECT col latest_col FROM t
UNION ALL
SELECT col FROM t
) x
where x.latest_col = outer_q.col
) newest_col -- need to get an output "4"
from t outer_q where col = 2;
This is possible here because outer_q is now in the where clause of the sub-query. It was used before in the sub-sub-query (the one with the UNION ALL), and this one was hiding it.
To try to make things clearer, now we have something like:
with t as (...)
select col,
(SELECT col FROM t WHERE col = outer_q.col) new_col,
(SELECT col FROM (Something more complex) WHERE ... = outer_q.col) new_col,
from t outer_q where col = 2;
So we now have the same level of "interiority".
EDIT: to answer the updated question, there is a little adaptation needed:
WITH t(col) AS
(
SELECT 1 FROM dual
UNION
SELECT 2 FROM dual
UNION
SELECT 3 FROM dual
UNION
SELECT 4 FROM dual
UNION
SELECT 5 FROM dual
),
t1(amount, col) AS
(
SELECT 100, 2 FROM dual
UNION
SELECT 200, 3 FROM dual
)
SELECT col,
(SELECT col FROM t WHERE col = outer_q.col) new_col,
(SELECT SUM(amount)
FROM
(SELECT col, col amount FROM t -- row is (1, 1), then (2, 2) etc
UNION ALL
SELECT col, amount FROM t1 -- row is (2, 100), then (3, 200) etc
)
WHERE col = outer_q.col
) newest_col -- gives 102 as it takes whole `SUM`
FROM t outer_q
WHERE col = 2;
The part to understand is in the innermost query: you want to sum both the column and the amount value, so you repeat the col value as if it was an amount.
Another way to obtain the same result (with more performance, I guess) would be to sum col and amount on the same row:
WITH t(col) AS
(
SELECT 1 FROM dual
UNION
SELECT 2 FROM dual
UNION
SELECT 3 FROM dual
UNION
SELECT 4 FROM dual
UNION
SELECT 5 FROM dual
),
t1(amount, col) AS
(
SELECT 100, 2 FROM dual
UNION
SELECT 200, 3 FROM dual
)
SELECT col,
(SELECT col FROM t WHERE col = outer_q.col) new_col,
(SELECT SUM(all_amount)
FROM
(SELECT col, col + amount all_amount FROM t1)
WHERE col = outer_q.col
) newest_col -- gives 315 as it takes whole `SUM`
FROM t outer_q
WHERE col = 2;
The inner query fails because you tried to push the outer_q.col reference two levels down. Correlated query goes only 1 level down
Reference: http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:1853075500346799932