I got table like this:
num |type|value
--------------
1 | a | 5
1 | b | 7
3 | c | 9
2 | a | 6
2 | b | 9
and want this kind of result:
num| value (a) | value (b)
-------------------------
1 | 5 | 7
2 | 6 | 9
You can use a self-join which will also remove the rows with just one value (num = 3 in your sample data)
select t1.num, t1.value as value_a, t2.value as value_b
from the_table t1
join the_table t2 on t1.num = t2.num and t2.type = 'b'
where t1.type = 'a'
You can use GROUP BY and CASE, as in:
select
num,
max(case when type = 'a' then value end) as value_a,
max(case when type = 'b' then value end) as value_b
from t
group by num
I'd join the table on itself, once for a and once for b
SELECT a.num, a.value, b.value
FROM mytable a
JOIN mytable b ON a.num = b.num AND a.type = 'a' AND b.type = 'b'
Related
ID|Class | Number
--+------+---------
1 | 1 | 58.2
2 | 1 | 85.4
3 | 2 | 28.2
4 | 2 | 55.4
The desired result would be:
Column1 |Number | Column2 | Number
--------+-------+---------+---------
1 | 58.2 | 2 |28.2
1 | 85.4 | 2 |55.4
What would be the required SQL?
You can user row_number() and aggregate:
select 1, max(case when seqnum % 2 = 1 then number end),
2, max(case when seqnum % 2 = 0 then number end)
from (select t.*,
row_number() over (partition by class order by id) as seqnum
from t
) t
group by ceiling(seqnum / 2.0);
The aggregation uses arithmetic to put pairs of rows for each class into one row.
try this
SELECT 1 AS Column1,t2.Number,2 AS Column2,t1.Number
FROM
(
SELECT *
FROM test11
) t2
INNER JOIN
(
SELECT *
FROM test11
) t1
ON t1.Class = t2.Class
WHERE t1.ID < t2.ID
ORDER BY t1.ID DESC
Demo in db<>fiddle
|id|last|
|2 |NULL|
|2 |2018|
|3 |NULL|
|3 |NULL|
|4 |2011|
|4 |2013|
This is what my current table looks like. A new 'status' column is to be created for each 'id' that must have the below 3 values.
1 - If Similar id and only one NULL value
2 - If Similar id and no NULL value
0 - If Similar id and both NULL value
EXAMPLE: Id 2 will get 1, id 3 will be assigned 0 and id 4 will get 2. There can be only 2 similar ids in the id table (there are no 3 values of 2 or 4)
I could find the similar id, but having difficulties writing the cases
select id
from table
group by id
having count(id) = 2
We can determine the status values by using aggregation:
WITH cte AS (
SELECT id,
CASE WHEN COUNT(*) > 1 AND COUNT(CASE WHEN last IS NULL THEN 1 END) = 1
THEN 1
WHEN COUNT(*) > 1 AND COUNT(CASE WHEN last IS NULL THEN 1 END) = 0
THEN 2
WHEN COUNT(*) > 1 AND COUNT(CASE WHEN last IS NULL THEN 1 END) = COUNT(*)
THEN 0 ELSE -1 END AS status
FROM yourTable
GROUP BY id
)
SELECT t1.*, t2.status
FROM yourTable t1
INNER JOIN cte t2
ON t1.id = t2.id;
Note that I assign a status value of -1 to any id which does not meet one of the three criteria. This would include any id which only appears once, among other edge cases.
You can do it this way
select a.id, last,
case
when exists(select 1 from _table b where a.id = b.id and coalesce(b.last,0) <> coalesce(a.last,0) and (a.last is null or b.last is null))
then 1
when exists(select 1 from _table b where a.id = b.id
and coalesce(b.last,0) <> coalesce(a.last,0))
and not exists(select 1 from _table b where a.id = b.id
and b.last is null)
then 2
when exists(select 1 from _table b where a.id = b.id )
and exists(select 1 from _table b where a.id = b.id and b.last is null and a.last is null having count(*) =
(select count(*) from _table b where a.id = b.id))
then 0
end as status
from _table a
Output:
id last status
2 NULL 1
2 2018 1
3 NULL 0
3 NULL 0
4 2011 2
4 2013 2
If you want one row per id:
select id,
(case count(*) filter (value is null)
when 1 then 1
when 0 then 2
when 2 then 3
end) as status
from t
group by id;
If you want this as a column on the original data, use window functions:
select t.*,
(case count(*) filter (value is null) over (partition by id)
when 1 then 1
when 0 then 2
when 2 then 3
end) as status
from t;
I have following table with data
id | COL1
=========
1 | b
2 | z
3 | b
4 | c
5 | b
6 | a
7 | b
8 | c
9 | a
So i know ID of 'z' (ID = 2) in the table and i will call it Z_ID.
I need to retrieve rows between 'a' and 'c' (including 'a' and 'c').
It must be first 'a' that comes after Z_ID.
'c' must come after Z_ID and after 'a' that i found previously.
Result that i am seeking is:
id | COL1
=========
6 | a
7 | b
8 | c
My SELECT looks like this
SELECT *
FROM table
WHERE id >= (
SELECT MIN(ID)
FROM table
WHERE COL1 = 'a' AND ID > 2
)
AND id <= (
SELECT MIN(ID)
FROM table
WHERE COL1 = 'c'AND ID > 2 and ID > (
SELECT MIN(ID)
FROM table
WHERE COL1 = 'a' AND ID > 2
)
)
I am getting the result that i want. But i am concerned about performance because i am using same subquery two times. Is there a way to reuse a result from first subquery?
Maybe there is cleaner way to get the result that i need?
Use a CTE which will return only once the result of the subquery that you use twice:
WITH cte AS (
SELECT MIN(ID) minid
FROM tablename
WHERE COL1 = 'a' AND ID > 2
)
SELECT t.*
FROM tablename t CROSS JOIN cte c
WHERE t.id >= c.minid
AND t.id <= (
SELECT MIN(ID)
FROM tablename
WHERE COL1 = 'c' and ID > c.minid
)
In your 2nd query's WHERE clause:
WHERE COL1 = 'c'AND ID > 2 and ID > (...
the condition AND ID > 2 is not needed because the next condition and ID > (... makes sure that ID will be greater than 2 so I don't use it either in my code.
See the demo.
Results:
| id | COL1 |
| --- | ---- |
| 6 | a |
| 7 | b |
| 8 | c |
You can use window functions for this:
select t.*
from (select t.*,
min(case when id > min_a_id and col1 = 'c' then id end) over () as min_c_id
from (select t.*,
min(case when col1 = 'a' then id end) over () as min_a_id
from (select t.*,
min(case when col1 = 'z' then id end) over () as z_id
from t
) t
where id > z_id
) t
) t
where id >= min_a_id and id < min_c_id;
I am trying to count matches between columns resulting from an INNER JOIN of two tables on unique values of a single column in one of the two tables. An example may make things more clear:
If I had the following two tables:
Table A
-------
id_A: info_A
1 'a'
2 'b'
3 'c'
3 'd'
Table B
-------
id_B: info_B
1 'a'
3 'c'
5 'b'
I want to find the unique id_A: [1,2,3] and the info_A associated with them: ['a','b','c','d'].
I want to create a table that looks like the following:
Table join of A+B
-----------------
id_A: info_A id_B info_B match_cnt
1 'a' 1 'a' 1
3 'c','d' 3 'c' 0.5
where match_cnt is the number of matches between info_A and info_B for a given id_A. FYI, the actual tables I'm working with have billions of rows.
A code chunk demonstrates what I've tried, plus variations (not shown below):
SELECT z.id_A, z.info_A, z.id_B, z.info_B
FROM(
SELECT u.id_A AS id_A, u.info_A AS info_A, y.id_B AS true_id_B, y.info_B AS true_info_B
FROM db.table_A u
WHERE EXISTS
( SELECT id_B, info_B
FROM table_B l
where l.id_B= u.id_A)
INNER JOIN table_B y
ON u.id_A = y.id_B
) z
You may use some thing like below :-
WITH T1 AS ( select ID_A ,count(1) as cnt from tableA inner join tableB on tableA.ID_A=tableB.ID_B and tableA.INFO_A=tableB.INFO_B group by ID_A,INFO_A)
select distinct tmp.ID_A,tmp.a,tmp.ID_B,tmp.b, (cnt/size(a)) from
(select ID_A ,collect_set(INFO_A) as a,ID_B,collect_set(INFO_B) as b from tableA inner join tableB on tableA.a=tableB.a group by tableA.a,tableB.a)
tmp join T1 on T1.ID_A=tmp.ID_A
select id
,collect_list (case when a=1 then info end) as info_a
,collect_list (case when b=1 then info end) as info_b
,count (case when a=1 and b=1 then 1 end) / count(*) as match_cnt
from (select id
,info
,min (case when tab = 'A' then 1 end) as a
,min (case when tab = 'B' then 1 end) as b
from ( select 'A' as tab ,id_A as id ,info_A as info from A
union all select 'B' as tab ,id_B as id ,info_B as info from B
) t
group by id
,info
) t
group by id
having min(a) = 1
and min(b) = 1
;
+----+-----------+--------+-----------+
| id | info_a | info_b | match_cnt |
+----+-----------+--------+-----------+
| 1 | ["a"] | ["a"] | 1.0 |
| 3 | ["c","d"] | ["c"] | 0.5 |
+----+-----------+--------+-----------+
i've really bad problem with this sql query.
base on my tables i need some thing like this result:
table1
Id | Type | Size |Count | OwnerId
___________________________________
1 A 1 12 1
2 A 2 12 1
3 B 1 14 1
4 B 1 20 1
5 A 1 12 2
6 A 1 17 2
table2
Id | name
_________
1 A
2 B
The Result
______________________
Name | Size1Type1 Count | Size2Type1 Count | Size1Type2 Count
thanks indeeeeed .
You did not specify what RDBMS you are using but you should be able to get the result by implementing an aggregate function with a CASE statement. This process is similar to a PIVOT:
select t2.name,
sum(case when t1.size = 1 and t1.type = 'a' then 1 else 0 end) Size1Type1Count,
sum(case when t1.size = 2 and t1.type = 'a' then 1 else 0 end) Size2Type1Count,
sum(case when t1.size = 1 and t1.type = 'b' then 1 else 0 end) Size1Type2Count,
sum(case when t1.size = 2 and t1.type = 'b' then 1 else 0 end) Size2Type2Count
from table1 t1
inner join table2 t2
on t1.ownerid = t2.id
group by t2.name
See SQL Fiddle with Demo
Result:
| NAME | SIZE1TYPE1COUNT | SIZE2TYPE1COUNT | SIZE1TYPE2COUNT | SIZE2TYPE2COUNT |
--------------------------------------------------------------------------------
| A | 1 | 1 | 2 | 0 |
| B | 2 | 0 | 0 | 0 |
If you want to include your count field, then you would use something like this:
select t2.name,
sum(case when t1.size = 1 and t1.type = 'a' then "Count" end) Size1Type1Count,
sum(case when t1.size = 2 and t1.type = 'a' then "Count" end) Size2Type1Count,
sum(case when t1.size = 1 and t1.type = 'b' then "Count" end) Size1Type2Count,
sum(case when t1.size = 2 and t1.type = 'b' then "Count" end) Size2Type2Count
from table1 t1
inner join table2 t2
on t1.ownerid = t2.id
group by t2.name;
See SQL Fiddle with Demo
Result:
| NAME | SIZE1TYPE1COUNT | SIZE2TYPE1COUNT | SIZE1TYPE2COUNT | SIZE2TYPE2COUNT |
--------------------------------------------------------------------------------
| A | 12 | 12 | 34 | (null) |
| B | 29 | (null) | (null) | (null) |
Or you could even perform multiple joins on the tables to get the result that you want:
select t2.name,
sum(t1_a1."count") Size1Type1Count,
sum(t1_a2."count") Size2Type1Count,
sum(t1_b1."count") Size1Type2Count,
sum(t1_b2."count") Size2Type2Count
from table2 t2
left join table1 t1_a1
on t1_a1.ownerid = t2.id
and t1_a1.size = 1
and t1_a1.type = 'a'
left join table1 t1_a2
on t1_a2.ownerid = t2.id
and t1_a2.size = 2
and t1_a2.type = 'a'
left join table1 t1_b1
on t1_b1.ownerid = t2.id
and t1_b1.size = 1
and t1_b1.type = 'b'
left join table1 t1_b2
on t1_b2.ownerid = t2.id
and t1_b2.size = 2
and t1_b2.type = 'b'
group by t2.name
See SQL Fiddle with Demo
SELECT Name, Type, Size, SUM(Count) AS 'Count' FROM Table1, Table2
WHERE Table1.OwnerID = Tabel2.Id
GROUP BY Name, Type, Size