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?
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 am new to SQL Server, used to work with MYSQL and trying to get the records from a table using Group By.
The table structure is given below:
SELECT S1.ID,S1.Template_ID,S1.Assigned_By,S1.Assignees,S1.Active FROM "Schedule" AS S1;
Output:
ID Template_ID Assigned_By Assignees Active
2 25 1 3 1
3 25 5 6 1
6 26 5 6 1
I need to get the values of all columns using the Group By statement below
SELECT Template_ID FROM "Schedule" WHERE "Assignees" IN(6, 3) GROUP BY "Template_ID";
Output:
Template_ID
25
26
I tried the following code to fetch the table using Group By, but it's fetching all the rows.
SELECT S1.ID,S1.Template_ID,S1.Assigned_By,S1.Assignees,S1.Active FROM "Schedule" AS S1 INNER JOIN(SELECT Template_ID FROM "Schedule" WHERE "Assignees" IN(6, 3) GROUP BY "Template_ID") AS S2 ON S2.Template_ID=S1.Template_ID
My Output Should be like,
ID Template_ID Assigned_By Assignees Active
2 25 1 3 1
6 26 5 6 1
I was wondering whether I can get ID of the column as well? I use the ID for editing the records in the web.
The query doesn't work as expected in MySQL either, except by accident.
Nonaggregated columns in MySQL aren't part of the SQL standard and not even allowed in MySQL 5.7 and later unless the default value of the ONLY_FULL_GROUP_BY mode is changed.
In earlier versions the result is non-deterministic.
The server is free to choose any value from each group, so unless they are the same, the values chosen are nondeterministic. Furthermore, the selection of values from each group cannot be influenced by adding an ORDER BY clause.
This means there's was no way to know what rows will be returned this query :
SELECT S1.ID,S1.Template_ID,S1.Assigned_By,S1.Assignees,S1.Active
FROM "Schedule" AS S1
GROUP BY Template_ID;
To get deterministic results you'd need a way to rank rows with the ranking functions introduced in MySQL 8, like ROW_NUMBER(). These are already available in SQL Server since SQL Server 2012 at least. The syntax is the same for both databases :
WITH ranked as AS
(
SELECT
ID,Template_ID,Assigned_By,Assignees Active,
ROW_NUMBER(PARTITION BY Template_ID Order BY ID)
FROM Scheduled
WHERE Assignees IN(6, 3)
)
SELECT ID,Template_ID,Assigned_By,Assignees Active
FROM ranked
Where RN=1
PARTITION BY Template_ID splits the result rows based on their Template_ID value into separate partitions. Within that partition, the rows are ordered based on the ORDER BY clause. Finally, ROW_NUMBER calculates a row number for each ordered partition row.
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.
Imagine you've got a table with 2 columns: ID and NAME. ID is simply a number, incrementing for each row (as you'd expect). NAME is some random varchar string. NAME can be same for different rows. Now, imagine you want to get the 3 latest occurences in this table, where NAME only may occur once.
For example, if you've got this data:
ID NAME
1 HELLO
2 TEST
3 HELLO
4 HELLO
5 QWERTY
6 HELLO
Then the result of the question should be:
6 HELLO
5 QWERTY
2 TEST
Is it possible achieve this on SQL level?
SELECT
MAX(ID),
Name
FROM
table
GROUP BY
Name
ORDER BY
MAX(ID) desc
LIMIT 3
SELECT MAX(ID), NAME
FROM THAT_TABLE
GROUP BY NAME
See: GROUP BY (Aggregate) Functions
I suppose, you need to use "DISTINCT" for the "name" column:
SELECT DISTINCT name, id FROM table_name ORDER BY id DESC LIMIT 3;
Another way to achieve this is to use "GROUP BY" for "name" (see another answer)
This is staight forward I believe:
I have a table with 30,000 rows. When I SELECT DISTINCT 'location' FROM myTable it returns 21,000 rows, about what I'd expect, but it only returns that one column.
What I want is to move those to a new table, but the whole row for each match.
My best guess is something like SELECT * from (SELECT DISTINCT 'location' FROM myTable) or something like that, but it says I have a vague syntax error.
Is there a good way to grab the rest of each DISTINCT row and move it to a new table all in one go?
SELECT * FROM myTable GROUP BY `location`
or if you want to move to another table
CREATE TABLE foo AS SELECT * FROM myTable GROUP BY `location`
Distinct means for the entire row returned. So you can simply use
SELECT DISTINCT * FROM myTable GROUP BY 'location'
Using Distinct on a single column doesn't make a lot of sense. Let's say I have the following simple set
-id- -location-
1 store
2 store
3 home
if there were some sort of query that returned all columns, but just distinct on location, which row would be returned? 1 or 2? Should it just pick one at random? Because of this, DISTINCT works for all columns in the result set returned.
Well, first you need to decide what you really want returned.
The problem is that, presumably, for some of the location values in your table there are different values in the other columns even when the location value is the same:
Location OtherCol StillOtherCol
Place1 1 Fred
Place1 89 Fred
Place1 1 Joe
In that case, which of the three rows do you want to select? When you talk about a DISTINCT Location, you're condensing those three rows of different data into a single row, there's no meaning to moving the original rows from the original table into a new table since those original rows no longer exist in your DISTINCT result set. (If all the other columns are always the same for a given Location, your problem is easier: Just SELECT DISTINCT * FROM YourTable).
If you don't care which values come from the other columns you can use a (bad, IMHO) MySQL extension to SQL and do:
SELECT * FROM YourTable GROUP BY Location
which will give a result set with one row per location and values for the other columns derived from the original data in an undefined fashion.
Multiple rows with identical values in all columns don't have any sense. OK - the question might be a way to correct exactly that situation.
Considering this table, with id being the PK:
kram=# select * from foba;
id | no | name
----+----+---------------
2 | 1 | a
3 | 1 | b
4 | 2 | c
5 | 2 | a,b,c,d,e,f,g
you may extract a sample for every single no (:=location) by grouping over that column, and selecting the row with minimum PK (for example):
SELECT * FROM foba WHERE id IN (SELECT min (id) FROM foba GROUP BY no);
id | no | name
----+----+------
2 | 1 | a
4 | 2 | c