I have a table like this and need to add column which will show info only in distinct rows:
ID Name
1 1001
2 1001
3 1001
4 1001
5 1002
6 1002
7 1002
8 1003
9 1004
10 1004
I need such result:
ID Name Result
1 1001 1
2 1001 NULL
3 1001 NULL
4 1001 NULL
5 1002 1
6 1002 NULL
7 1002 NULL
8 1003 1
9 1004 1
10 1004 NULL
The result column basically selects 1 only for distinct Name values.
This should be some basic query, but I cannot figure it.
Since ordering will wreak havoc with your concept, I'll assume that you'll always sort by ID.
You can do something like this:
select ID, Name,
case (select count(*) from table t2 where t2.Name=t1.Name and t1.ID > t2.ID)
when 0 then 1
else null
end as Result
from table t1
This will count all the rows with the same name, and with a lower ID than the row processed. If there are no such rows, then it's a new name, so it'll get the 1, otherwise, it will get a null value.
You can use row_number to get the first instance of a group, in this case Name:
select ID, Name,
case row_number() over(partition by Name order by ID)
when 1 then 1 end Result
from YourTable
Try that
SELECT ID,
NAME,
Case When x.minId Is Not Null Then 1 Else Null End As Result
FROM Table
left JOIN (
SELECT Name, min(id) minId
FROM Table ) x
on x.minId = Table.Id
and x.Name = Table.Name
Related
I have a table
Table name - commands
id
name
status
group_id
id - number
name - string
status - 0 or 1
group_id - number
I need to sort as follows: for all elements with the same group_id I have to check if at least one has a status of 1, if so, then leave, if not, then remove such a group and so on for all group_id
I tried to do it through GROUP BY, and then using HAVING to remove unnecessary groups, but this way I don't get the whole table to be displayed or a query that does not work.
I think it should look like:
SELECT COUNT(*) FROM commands GROUP BY group_id HAVING *condition*
Please let me know if there are any other commands to use.
id
name
status
group_id
1
name1
0
1
2
name2
0
1
3
name3
0
2
4
name4
1
2
5
name5
1
2
6
name6
0
3
7
name7
1
4
Result:
id
name
status
group_id
3
name3
0
2
4
name4
1
2
5
name5
1
2
7
name7
1
4
In Postgres, that's a good spot to use a boolean window function:
select *
from (
select t.*, bool_or(status = 1) over(partition by group_id) has_status_1
from mytable t
) t
where has_status_1
bool_or checks if any row in the group satisfies its predicate ; we can use this information for filtering.
The upside is that the table is scanned only once, as opposed to the correlated subquery solution.
You may use EXISTS operator with a correlated subquery as the following:
SELECT id, name, status, group_id
FROM table_name T
WHERE EXISTS(SELECT 1 FROM table_name D WHERE D.group_id = T.group_id AND D.status=1)
ORDER BY id
See a demo.
I'd appreciate some help on the following SQL problem:
I have a table of 3 columns:
ID Group Value
1 1 5
1 1 5
1 2 10
1 2 10
1 3 20
2 1 5
2 1 5
2 1 5
2 2 10
2 2 10
3 1 5
3 2 10
3 2 10
3 2 10
3 4 50
I need to group by ID, and I would like to SUM the values based on DISTINCT values in Group. So the value for a group is only accounted for once even though it may appear multiple for times for a particular ID.
So for IDs 1, 2 and 3, it should return 35, 15 and 65, respectively.
ID SUM
1 35
2 15
3 65
Note that each Group doesn't necessarily have a unique value
Thanks
the CTE will remove all duplicates, so if there a sdiffrenet values for ID and Group, it will be counted.
The next SELECT wil "GROUP By" ID
For Pstgres you would get
WITH CTE as
(SELECT DISTINCT "ID", "Group", "Value" FROM tablA
)
SELECT "ID", SUM("Value") FROM CTE GROUP BY "ID"
ORDER BY "ID"
ID | sum
-: | --:
1 | 35
2 | 15
3 | 65
db<>fiddle here
Given what we know at the moment this is what I'm thinking...
The CTE/Inline view eliminate duplicates before the sum occurs.
WITH CTE AS (SELECT DISTINCT ID, Group, Value FROM TableName)
SELECT ID, Sum(Value)
FROM CTE
GROUP BY ID
or
SELECT ID, Sum(Value)
FROM (SELECT DISTINCT * FROM TableName) CTE
GROUP BY ID
I want to achieve these two requirements using a single query. Currently I'm using 2 queries in the program and use C# to do the process part something like this.
Pseudocode
select top 1 id from table where type=b
if result.row.count > 0 {var typeBid = row["id"]}
select * from table where id >= {typeBid}
else
select * from table
Req1: If there is records exist with type=b, Result should be latest row with type=b and all other rows added after.
Table
--------------------
id type date
--------------------
1 b 2021-10-15
2 a 2021-11-16
3 b 2021-11-19
4 a 2021-12-02
5 c 2021-12-12
6 a 2021-12-16
Result
--------------------
id type date
--------------------
3 b 2021-11-19
4 a 2021-12-02
5 c 2021-12-12
6 a 2021-12-16
Req2: There is NO record exist with type=b. Query should select all the records in the table
Table
---------------------
id type date
---------------------
1 a 2021-10-15
2 a 2021-11-16
3 a 2021-11-19
4 a 2021-12-02
5 c 2021-12-12
6 a 2021-12-16
Result
--------------------
id type date
--------------------
1 a 2021-10-15
2 a 2021-11-16
3 a 2021-11-19
4 a 2021-12-02
5 c 2021-12-12
6 a 2021-12-16
with max_b_date as (select max(date) as date
from table1 where type = 'b')
select t1.*
from table1 t1
cross join max_b_date
where t1.date >= max_b_date.date
or max_b_date.date is null
(table is a SQL reserved word, https://en.wikipedia.org/wiki/SQL_reserved_words, so I used table1 as table name instead.)
https://dbfiddle.uk/?rdbms=sqlserver_2019&fiddle=bd05543a9712e27f01528708f10b209f
Please try this(It's somewhat deep but might you exact looking for)
select ab.* from
((select top 1 id, type, date from test where type = 'b' order by id desc)
union
select * from test where type != 'b') as ab
where ab.id >= (select COALESCE((select top 1 id from test where type = 'b' order by id desc), 0))
order by ab.id;
https://dbfiddle.uk/?rdbms=sqlserver_2019&fiddle=739eb6bfee787e5079e616bbf4e933b1
Looks Like you can use an OR condition here
SELECT
*
FROM
(
SELECT
*,
BCount = COUNT(CASE type WHEN 'B' THEN 1 ELSE NULL END)-- to get the Count of Records with Type b.
FROM Table
)Q
WHERE
(
BCount > 0 AND id >= (select top 1 id from table where type=b)-- if there are Row's with Type b then select Req#1
)
OR
(
BCount = 0 -- if THere are no rows with Type B select All
)
I am trying to create a flag column called "Related" to use in reporting to highlight specific rows that are related based on the ID column (1 = related, NULL = not related). The original table "table1" looks like below:
Name ID Related
--------------------------------
Jack 101 NULL
John 101 NULL
Pat 105 NULL
Ben 106 NULL
Jordan 106 NULL
George 300 NULL
Alan 500 NULL
Bill 200 NULL
Bob 200 NULL
I then used this UPDATE statement below:
UPDATE a
SET Related = 1
FROM table1 a
JOIN (SELECT ID FROM table1 GROUP BY ID HAVING COUNT(*) > 1) b
ON a.ID = b.ID
Below is the result of this update statement:
Name ID Related
--------------------------------
Jack 101 1
John 101 1
Pat 105 NULL
Ben 106 1
Jordan 106 1
George 300 NULL
Alan 500 NULL
Bill 200 1
Bob 200 1
This gets me close but I need for it to instead of assigning the number 1 to each related row, to increment the number for each set of related rows based on their different ID column values.
Desired result:
Name ID Related
--------------------------------
Jack 101 1
John 101 1
Pat 105 NULL
Ben 106 2
Jordan 106 2
George 300 NULL
Alan 500 NULL
Bill 200 3
Bob 200 3
This is a possible solution using dense_rank to number your related values and an updateable CTE
with r as (
select id
from t
group by id having Count(*) > 1
),
n as (
select t.id, t.related, Dense_Rank() over (order by r.id) r
from r
join t on t.id = r.id
)
update n set related = r
You can do this without a self-join, just using window functions in a CTE, and updating the CTE directly:
WITH tCounted AS (
SELECT
t.id,
t.related,
c = COUNT(*) OVER (PARTITION BY r.id)
FROM t
),
tWithRelated as (
SELECT
t.id,
t.related,
rn = DENSE_RANK() OVER (ORDER BY r.id)
FROM tCounted
WHERE c > 1
)
UPDATE tWithRelated
SET related = rn;
Use an updateable CTE - comments explain the logic.
with cte1 as (
select [Name], ID, Related
-- Get the count within the id partition, less 1 as specified
, count(*) over (partition by id) - 1 cnt
-- Get the row number within the id partition
, row_number() over (partition by id order by id) rn
from #Test
), cte2 as (
select [Name], ID, Related, cnt, rn
-- Add 1 *only* if the count is > 0 *and* its the first row in the id partition
, case when cnt > 0 then sum(case when cnt > 0 and rn = 1 then 1 else 0 end) over (order by id) else null end NewRelated
from cte1
)
update cte2 set Related = NewRelated;
This doesn't assume Related is already null and works for more than 2 rows for any given ID.
It does assume that one can order by the ID column - even though the data provided doesn't do that.
Goal:
If a person has two candy number, number 1 should always display first. No need to display candy number 2.
If a person does not have number 1, it should display number 2 instead.
Display all data
(int)(int) (nvarchar) (int)
Id fId Name Candy Number
---------------------------------
1 12 Kimn 1
2 12 Kimn 2
3 19 Lisa 1
4 15 John 2
5 16 Maria 2
6 16 Maria 1
7 17 Mao 2
Requested result:
Id fId Name Candy Number
---------------------------------
1 12 Kimn 1
3 19 Lisa 1
4 15 John 2
6 16 Maria 1
7 17 Mao 2
Problem:
It doesn't work so well for me to display it.
Tried using case and end in where statement but the code didn't fit to the purpose.
Any idea?
select *
from
table
where
candynumber =
CASE WHEN b.MatchType = 1
THEN 1
ELSE 2
END
Thank you!
This can be using row_number() window function:
select Id, fId, Name, Candy_Number from (
select your_table.*, row_number() over(partition by fId order by Candy_Number) as rn from your_table
) t
where rn = 1
order by id
This gives one row per fId, with lower Candy_Number.
You can try this :
SELECT candyWrapper.ID,
candyWrapper.FID,
outerHardCandy.Name,
outerHardCandy.Number
FROM (SELECT innerSoftCandy.Name,
CASE
WHEN (SUM(innerSoftCandy.Number) = 3) OR (SUM(innerSoftCandy.Number) = 1) THEN 1
WHEN (SUM(innerSoftCandy.Number) = 2) THEN 2
END AS Number
FROM Candy innerSoftCandy
GROUP BY innerSoftCandy.Name
) outerHardCandy
INNER JOIN Candy candyWrapper ON (outerHardCandy.Name = candyWrapper.Name AND outerHardCandy.Number = candyWrapper.Number)
ORDER BY candyWrapper.ID
You can see this here -> http://rextester.com/BBD89608