I am trying to count the number records based on the text in the table
Am having Table Structure Like this
SN_ID NUMBER
PERSON_ID NUMBER
NOTICE_TYPE VARCHAR2
and the contents of the table like this
SN_ID PERSON_ID NOTICE_TYPE
-------+-----------+--------------
1 5 Appreciation
2 5 Warning
3 1 Warning
4 5 Incident
5 2 Warning
6 5 Warning
I want to count the number Appreciation, Warning and Incident records for the person with an Id = 5
select Notice_type, count(*) from [Table]
where person_id=5
group by notice_type
SELECT NOTICE_TYPE, count(SN_ID)
FROM [Table]
WHERE PERSON_ID = 5
GROUP BY NOTICE_TYPE
This is slightly different from MikkaRin answer.
Difference is count(SN_ID). I took only one column here. Because it is more optimized method than taking whole column into the count() function. This will affected to large queries.
p.s. actually we should get the primary key into the count() function. Here SN_ID look like the PK.
Related
I have a table like this:
Id
Date
Steps
Distance
1
2016-06-01
1000
1
There are over 1000 records and 50 Ids in this table, most ids have about 20 records, and some ids only have 1, or 2 records which I think are useless.
I want to create a table that excludes those ids with less than 5 records.
I wrote this code to find the ids that I want to exclude:
SELECT
Id,
COUNT(Id) AS num_id
FROM `table`
GROUP BY
Id
ORDER BY
num_id
Since there are only two ids I need to exclude, I use WHERE clause:
CREATE TABLE `` AS
SELECT
*
FROM ``
WHERE
Id <> 2320127002
AND Id <> 7007744171
Although I can get the result I want, I think there are better ways to solve this kind of problem. For example, if there are over 20 ids with less than 5 records in this table, what shall I do? Thank you.
Consider this:
CREATE TABLE `filtered_table` AS
SELECT *
FROM `table`
WHERE TRUE QUALIFY COUNT(*) OVER (PARTITION BY Id) >= 5
Note: You can remove WHERE TRUE if it runs successfully without it.
I need a little help. I have this (simplified) table:
ID
Title
Subtype
RelatedUniqueID
1
My Title 1
1
NULL
2
My Title 2
1
NULL
3
My Title 3
2
NULL
4
My Title 4
2
NULL
5
My Title 5
2
NULL
6
My Title 6
3
NULL
What I am trying to accomplish is generating the same uniqueidentifier for all rows having the same subtype.
So result would be this:
ID
Title
Subtype
RelatedUniqueID
1
My Title 1
1
439753d3-9103-4d0e-9dd0-569dc71fd6a3
2
My Title 2
1
439753d3-9103-4d0e-9dd0-569dc71fd6a3
3
My Title 3
2
d0f08203-1197-4cc7-91bb-c4ca34d7cb0a
4
My Title 4
2
d0f08203-1197-4cc7-91bb-c4ca34d7cb0a
5
My Title 5
2
d0f08203-1197-4cc7-91bb-c4ca34d7cb0a
6
My Title 6
3
055838c6-a814-4bd1-a859-63d4544bb449
Requirements
One query to update all rows at once
The actual table has many more rows with hundreds of subtypes, so manually building a query for each subtype is not an option
Using SQL Server 2017
Thanks for any assist.
Because newid() is applied per-row, you have to generate the values first, so this has to involve the use of a temporary or permanent table to store the correlated ID>Subtype value.
So first you need to generate the GUID values per Subtype :
with subtypes as (
select distinct subtype
from t
)
select Subtype, NewId() RelatedId into #Id
from subtypes
And then you can use an updatable CTE to apply these to your base table:
with r as (
select t.*, id.RelatedId
from #id id
join t on t.subtype=id.Subtype
)
update r
set relatedUniqueId=RelatedId
See example DB<>Fiddle
You can use an updatable CTE with a window function to get this data:
with r as (
select t.*,
RelatedId = first_value(newid()) over (partition by t.Subtype order by ID rows unbounded preceding)
from t
)
update r
set relatedUniqueId = RelatedId;
db<>fiddle
I warn though, that newid() is somewhat unpredictable in when it is calculated, so don't try messing about with a joined update (unless you pre-save the IDs like #Stu has done).
For example, see this fiddle, the IDs were calculated differently for every row.
I have found the single query solution.
Pre-requirement for this to work is that RelatedUniqueID must already contain random values. (e.g. set default field value to newid)
UPDATE TestTable SET ForeignUniqueID = TG.ForeignUniqueID FROM TestTable TG INNER JOIN TestTable ON TestTable.SubType = TG.SubType
Update
As Stu mentions in the comments, this solution might affect performance on large datasets. Please keep that in mind.
Can anyone help? My trouble is that people might have the same id or different and have different name spellings. If I group by id (which is not the primary key) I get a different amount of rows than if I group by ID and name. How do I just group by ID, while still having the ID and Name in the select?
Create Table Client(ID Int, Name Varchar(15))
Insert Into Client VALUES(11,'Batman'),(22,'Batman'),(33,'Robin'),(44,'Joker'),(44,'The Joker'),(33,'Robin')
Select Count(ID) From Client
Select * From Client
--This returns 4 rows as it should
Select Count (ID)
From Client
Group By ID
--This returns 5 rows because Joker and The Joker have different names, but the same ID. I want to count by ID and not the name, since so many have typos.
Select Count (ID), [Name] , ID
From Client
Group By ID, [Name]
How do I do this and have it work?
Select Count (ID), [Name] , ID
From Client
Group By ID --<< Always throws and error unless I include Name, which
--returns too many rows.
It should return
Count Name ID
1 Batman 11
1 Batman 22
2 Joker 44 --<< Correct
2 Robin 33
And not
Count Name ID
1 Batman 11
1 Batman 22
2 Robin 33
1 Joker 44 --Wrong
1 The Joker 44 --Wrong
using select count(*) from ClientLog will tell you exactly how many records there are in your table. If your ID field is the primary key, then select count(ID) from ClientLog should return the same number.
Your first query is a little confusing, because you're grouping by ID but not displaying the ID. So you're likely getting a row for each record, where the row value is 1.
Your 2nd query is also a bit confusing, because there's no aggregation happening (since your ID field is unique).
What specifically are you trying to obtain in your query (if anything besides just how many records you have in your table)?
I have an SQL Server 2012 table with ID, First Name and Last name. The ID is unique per person but due to an error in the historical feed, different people were assigned the same id.
------------------------------
ID FirstName LastName
------------------------------
1 ABC M
1 ABC M
1 ABC M
1 ABC N
2 BCD S
3 CDE T
4 DEF T
4 DEG T
In this case, the people with ID’s 1 are different (their last name is clearly different) but they have the same ID. How do I query and get the result? The table in this case has millions of rows. If it was a smaller table, I would probably have queried all ID’s with a count > 1 and filtered them in an excel.
What I am trying to do is, get a list of all such ID's which have been assigned to two different users.
Any ideas or help would be very appreciated.
Edit: I dont think I framed the question very well.
There are two ID's which are present multiple time. 1 and 4. The rows with id 4 are identical. I dont want this in my result. The rows with ID 1, although the first name is same, the last name is different for 1 row. I want only those ID's whose ID is same but one of the first or last names is different.
I tried loading ID's which have multiple occurrences into a temp table and tried to compare it against the parent table albeit unsuccessfully. Any other ideas that I can try and implement?
SELECT
ID
FROM
<<Table>>
GROUP BY
ID
HAVING
COUNT(*) > 1;
SELECT *
FROM myTable
WHERE ID IN (
SELECT ID
FROM myTable
GROUP BY ID
HAVING MAX(LastName) <> MIN(LastName) OR MAX(FirstName) <> MIN(FirstName)
)
ORDER BY ID, LASTNAME
I have a table as below.
OId CustId CustSeq
1 A 10
1 A 20
2 A 10
2 A 20
I'm trying to extract unique records as below.
OId CustId CustSeq (Different OIds with different CustSeqs)
1 A 10
2 A 20
May I know how I could come out the query to extract like above?
Just use DISTINCT. That's what it was desgined for although group by will work.
http://www.techonthenet.com/oracle/distinct.php
SELECT DISTINCT OID, CUSTID, CUSTSEQ
FROM TABLE_NAME
Use DISTINCT, and also use Group By for the 2 columns CustId & CustSeq
Check here for example Is it possible to GROUP BY multiple columns using MySQL?