I guess that is an easy question to solve, but I'm researching for an hour for it's answer.
I have a table with three columns: "id","id_x" and "name". But it's populated with repeated values, like this:
id id_x name
1 100 Name_aaa
2 100 Name_aaa
3 100 Name_aaa
4 100 Name_aaa*
5 101 Name_bbb
6 101 Name_bbb*
Ok, ok, I didn't create this table, and I can't modify them... I just wanna know what query I can execute to return only the values "100 - Name_aaa" and "101 - name_bbb"... Note that has an "*" after some names. I'd like to group only by the "id_x".
Is there any way to do it without using subqueries or joins?
Thanks in advance!
Somewhat untested, but this should do it
select id_x, min(name) as name
from table
group by id_x
Try this,
select distinct id_x , name from tablename
select distinct
id_x,
case when name ~ E'\\*$' then substring(name, 1, length(name)-1)
else name end
from t;
Or:
SELECT DISTINCT ON (id_x) id_x, name FROM table ORDER BY id_x, name;
Related
I've been looking for an answer to this but couldn't find anything the same as this particular situation.
So I have a one table that I want to remove duplicates from.
__________________
| JobNumber-String |
| JobOp - Number |
------------------
So there are multiples of these two values, together they make the key for the row. I want keep all distinct job numbers with the lowest job op. How can I do this? I've tried a bunch of things, mainly trying the min function, but that only seems to work on the entire table not just the JobNumber sets. Thanks!
Original Table Values:
JobNumber Jobop
123 100
123 101
456 200
456 201
780 300
Code Ran:
DELETE FROM table
WHERE CONCAT(JobNumber,JobOp) NOT IN
(
SELECT CONCAT(JobNumber,MIN(JobOp))
FROM table
GROUP BY JobNumber
)
Ending Table Values:
JobNumber Jobop
123 100
456 200
780 300
With SQL Server 2008 or higher you can enhance the MIN function with an OVER clause specifying a PARTITION BY section.
Please have a look at https://msdn.microsoft.com/en-us/library/ms189461.aspx
You can simply select the values you want to keep:
select jobOp, min(number) from table group by jobOp
Then you can delete the records you don't want:
DELETE t FROM table t
left JOIN (select jobOp, min(number) as minnumber from table group by jobOp ) e
ON t.jobob = e.jobob and t.number = e.minnumber
Where e.jobob is null
I like to do this with window functions:
with todelete as (
select t.*, min(jobop) over (partition by numbers) as minjop
from table t
)
delete from todelete
where jobop > minjop;
It sounds like you are not using the correct GROUP BY clause when using the MIN function. This sql should give you the minimum JobOp value for each JobNumber:
SELECT JobNumber, MIN(JobOp) FROM test.so_test GROUP BY JobNumber;
Using this in a subquery, along with CONCAT (this is from MySQL, SQL Server might use different function) because both fields form your key, gives you this sql:
SELECT * FROM so_test WHERE CONCAT(JobNumber,JobOp)
NOT IN (SELECT CONCAT(JobNumber,MIN(JobOp)) FROM test.so_test GROUP BY JobNumber);
My Table: table1
ID Name Family
1 A AA
2 B BB
3 A AB
4 D DD
5 E EE
6 A AC
SQL command on Access:
select count(*) from table1
Output: ------------> True
6 row(s)
I tried to count unique names:
Expected output: 4 row(s)
select count(distinct Name) from table1
Output on Access: ------------> Error
What changes do I need to make to my query?
Try this
SELECT Count(*) AS N
FROM
(SELECT DISTINCT Name FROM table1) AS T;
Read this for more info.
Access-Engine does not support
SELECT count(DISTINCT....) FROM ...
You have to do it like this:
SELECT count(*)
FROM
(SELECT DISTINCT Name FROM table1)
Its a little workaround... you're counting a DISTINCT selection.
A quick trick to use for me is using the find duplicates query SQL and changing 1 to 0 in Having expression. Like this:
SELECT COUNT([UniqueField]) AS DistinctCNT FROM
(
SELECT First([FieldName]) AS [UniqueField]
FROM TableName
GROUP BY [FieldName]
HAVING (((Count([FieldName]))>0))
);
Hope this helps, not the best way I am sure, and Access should have had this built in.
i have a table where termid,termversion are two primary key.
column present in table - termid,termversion,name
I want to select all term whose name ilike '%AB%' and the result should contain each matching term with maximum version number.
Example:
id name ver
1 ABBBB 1
1 ABBBB 2
1 ABBBB 3
2 ABC 1
2 ABC 2
output should come
1 ABBBB 3
2 ABC 2
I want to write this query in hibernate using
Criteria...if any one can suggest me in hibernate then its really good else at least help me in writing the sql query.
PS I am using postgresql
I think that is what you are looking for:
SELECT id, name, MAX(ver)
FROM table
WHERE name ILIKE '%AB%'
GROUP BY name, id -- I assume: id == id' <==> name == name'
is it?
select id, name, max(ver) from mytable where name like '%AB%' group by id, name
can you try this sql command.
select id,name,max(ver) from table_name group by id, name having name like '%AB%'
I am selecting all badge numbers from a database where category is equal to 1.
category | badge number
0 | 1
1 | 1
2 | 5
1 | 1
Sometimes the category is duplicated, is there a way to only get unique badge numbers from the database?
So above there is two 1's in category, each with badge number 1. How can I make sure the result only gives '1' rather than '1,1'
Use DISTINCT key word in the SELECT statement.
SELECT DISTINCT badge_number FROM Your_Table WHERE category = 1
Use the distinct keyword in your select.
select distinct badge_number from table_name where category = 1
Have you tried Select Distinct :
SELECT DISTINCT [badge number] from table
where Category=1
http://www.w3schools.com/sql/sql_distinct.asp
Select Distinct Badgenumber from table where Category = 1
SELECT DISTINCT BadgeNumber FROM dbo.TableName
Where Category = 1
Edited:
Ohh, there are so many posts already .... !!
I have one table named GUYS(ID,NAME,PHONE) and i need to add a count of how many guys have the same name and at the same time show all of them so i can't group them.
example:
ID NAME PHONE
1 John 335
2 Harry 444
3 James 367
4 John 742
5 John 654
the wanted output should be
ID NAME PHONE COUNT
1 John 335 3
2 Harry 444 1
3 James 367 1
4 John 742 3
5 John 654 3
how could i do that? i only manage to get lot of guys with different counts.
thanks
Update for 8.0+: This answer was written well before MySQL version 8, which introduced window functions with mostly the same syntax as the existing ones in Oracle.
In this new syntax, the solution would be
SELECT
t.name,
t.phone,
COUNT('x') OVER (PARTITION BY t.name) AS namecounter
FROM
Guys t
The answer below still works on newer versions as well, and in this particular case is just as simple, but depending on the circumstances, these window functions are way easier to use.
Older versions: Since MySQL, until version 8, didn't have analytical functions like Oracle, you'd have to resort to a sub-query.
Don't use GROUP BY, use a sub-select to count the number of guys with the same name:
SELECT
t.name,
t.phone,
(SELECT COUNT('x') FROM Guys ct
WHERE ct.name = t.name) as namecounter
FROM
Guys t
You'd think that running a sub-select for every row would be slow, but if you've got proper indexes, MySQL will optimize this query and you'll see that it runs just fine.
In this example, you should have an index on Guys.name. If you have multiple columns in the where clause of the subquery, the query would probably benefit from a single combined index on all of those columns.
Use an aggregate Query:
select g.ID, g.Name, g.Phone, count(*) over ( partition by g.name ) as Count
from
Guys g;
You can still use a GROUP BY for the count, you just need to JOIN it back to your original table to get all the records, like this:
select g.ID, g.Name, g.Phone, gc.Count
from Guys g
inner join (
select Name, count(*) as Count
from Guys
group by Name
) gc on g.Name = gc.Name
In Oracle DB you can use
SELECT ID,NAME,PHONE,(Select COUNT(ID)From GUYS GROUP BY Name)
FROM GUYS ;
DECLARE #tbl table
(ID int,NAME varchar(20), PHONE int)
insert into #tbl
select
1 ,'John', 335
union all
select
2 ,'Harry', 444
union all
select
3 ,'James', 367
union all
select
4 ,'John', 742
union all
select
5 ,'John', 654
SELECT
ID
, Name
, Phone
, count(*) over(partition by Name)
FROM #tbl
ORDER BY ID
select id, name, phone,(select count(name) from users u1 where u1.name=u2.name) count from users u2
try
select column1, count(1) over ()
it should help