I have a table like this:
1 | Madrid | 45000
2 | Berlin | 35000
3 | Berlin | 65000
Now I want to show a result like this:
1 | Madrid | 45000
2 | Berlin | "Different Values"
So basically I want to use a "Group By" and if it is grouped, then change the value of some columns to a manual string.
I thought about using a view, update all values in this view to the string where i have duplications of the grouped column and then use the real query.
I even thought about implementing an assembly into the sql server that does this, but I don't find any good tutorials on this, only that you can do it.
Or has someone an even better idea? (The real tables used here are huge and the sql query does take sometimes up to 3 minutes to perform, so I made this example simple and I didn't wanted to work here with counts on every column to group, because that could take more than just a few minutes.
Something like this should work
select min(id) as id,
name,
case when count(*) = 1
then cast(sum(value) as varchar)
else 'Different values'
end as value
from your_table
group by name
I would do this as:
select min(id) as id, city,
(case when min(value) = max(value)
then cast(max(value) as varchar(255))
else 'Different Values'
end) as result
from t
group by city;
In fact, I might use something more informative than "different values", such as the range:
select min(id) as id, city,
(case when min(value) = max(value)
then cast(max(value) as varchar(255))
else cast(min(value) as varchar(255)) + '-' + cast(max(value) as varchar(255))
end) as result
from t
group by city;
Related
I am writing a query which fetches details from different tables. In one column I want to print count value of a column. If the count value of the column is greater than 1, I want to print the count of the column else I want to print value in the field.
I want to build a query which will give me count of user_id from table 1 & 2. if the count user_id is greater than 1, then print count (user_id) else print value of user_id
Table:1
| user_id |
| John |
| Bob |
| Kris |
| Tom |
Table:2
| user_id |
| Rob |
query result should list count of table1 as it greater than 1. Table2 should list Rob as it is lesser than 2
You want to select user IDs (names actually) from a table. If it's just one row then show that name, otherwise show the number of entries instead. So, just use a CASE expression to check whether count is 1 or greater than 1.
You probably need CAST or CONVERT to turn the count number into a string, so the CASE expression always returns the same type (this is how CASE works).
select
case when count(*) > 1
then cast(count(*) as varchar(100))
else max(user_id)
end as name_or_count
from mytable
Window Functions come to mind but since your user_ids are not numbers, you'll run into an issue where you can't have two different data types in the same column. See how this works for you. Make sure to cast the varchar numbers back to integer if this script is part of a larger process.
with cte as
(select 'John' as user_id union all
select 'Bob' as user_id union all
select 'Kris' as user_id union all
select 'Tom' as user_id)
select distinct case when count(*) over() > 1
then cast(count(*) over() as varchar) else user_id end
from cte
with cte as
(select 'Rob' as user_id)
select distinct case when count(*) over() > 1
then cast(count(*) over() as varchar) else user_id end
from cte
I'm trying to figure out the SQL to aggregate the data in my Vehicles table:
Id | Name | Make
---+-------+------
1 Car Ford
1 Car Volvo
1 Car BMW
2 Bike Honda
3 Truck Tata
3 Truck abc
4 Train bullet
in order to return the following:
Id | Name | Result
---+-------+------
1 Car 3 items selected
2 Bike Honda
3 Truck 2 items selected
4 Train bullet
So if an Id,Name combination has more than one make then output 'X items selected' where X is the number of makes for that combination. Otherwise output the Make as-is. Note that the make will be unique for each Id,Name combination.
Can this be achieved using a GROUP BY expression? If so what aggregate function do I need in place of ??? below? Or can it be achieved some other way?
select Id,
Name,
case when count(Make) > 1 then convert(varchar(10), count(Make)) + ' items selected'
else ??? end Result
from Vehicles
group by Id, Name
I'm using SQL Server 2008.
Use MIN() or MAX():
select Id, Name,
(case when count(Make) > 1
then convert(varchar(10), count(Make)) + ' items selected'
else min(Make)
end) as Result
from Vehicles
group by Id, Name;
If there is only one row, then the MIN() and MAX() are the values on that row.
Use CTE (Common Table Expression) because that increase your query performance.especially in your query. check the Query
WITH Vehicles_CTE (Id, Name, Result,Make)
AS (
SELECT Id, Name, COUNT(1) Result, MAX(Make) Make FROM Vehicles
Group By Id, Name
)
SELECT Id, Name, CASE WHEN Result>1
THEN Cast(Result AS varchar(10)) + ' items selected'
ELSE Make End Result FROM Vehicles_CTE
I'm strugling with what on the first sight appeared to be simple SQL query :)
So I have following table which has three columns: PlayerId, Gender, Result (all of type integer).
What I'm trying to do, is to select distinct players of gender 2 (male) with number of each results.
There are about 50 possible results, so new table should have 51 columns:
|PlayerId | 1 | 2 | 3 | ... | 50 |
So I would like to see how many times each individual male (gender 2) player got specific result.
*** In case question is still not entirely clear to you: After each game I insert a row with a player ID, gender and result (from 1 - 50) player achieved in that game. Now I'd like to see how many times each player achieved specfic results.
If there are 50 results and you want them in columns, then you are talking about a pivot. I tend to do these with conditional aggregation:
select player,
sum(case when result = 0 then 1 else 0 end) as result_00,
sum(case when result = 1 then 1 else 0 end) as result_01,
. . .
sum(case when result = 50 then 1 else 0 end) as result_50
from t
group by player;
You can choose a particular gender if you like, with where gender = 2. But why not calculate all at the same time?
try
select player, result, count(*)
from your_table
where Gender = 2
group by player, result;
select PleyerId from tablename where result = 'specific result you want' and gender = 2 group by PleyerId
The easiest way is to use pivoting:
;with cte as(Select * from t
Where gender = 2)
Select * from cte
Pivot(count(gender) for result in([1],[2],[3],....,[50]))p
Fiddle http://sqlfiddle.com/#!3/8dad5/3
One note: keeping gender in scores table is a bad idea. Better make a separate table for players and keep gender there.
Let's say I want to find mentions of names listed in one table within another. So for instance I have this table:
ID | Name
----+-----------------------
1 | PersonA
2 | PersonB
3 | PersonC
4 | PersonD
Now I want to search a field in another table for these persons' names and produce a count for each. Here's what I've tried, to no avail:
select
Name,
sum(
select
count(*)
from Posts
where Posts.Body like '%[^N]' + [Name] + '%'
) as [Count]
from NamesTable
order by Name;
I am using Data Explorer here on SE, so whatever syntax will work there is what I need. I'm not sure how to get this working or if this is even the best approach.
Your query is very close. You just don't need the sum() in the outer query:
select Name,
(select count(*)
from Posts
where Posts.Body like '%[^N]' + [Name] + '%'
) as [Count]
from NamesTable
order by Name;
What I am looking for is to group by and count the total of different data in the same table and have them show in two different columns. Like below.
Data in table A
Fields:
Name Type
Bob 1
John 2
Bob 1
Steve 1
John 1
Bob 2
Desired result from query:
Name Type 1 Type 2
Bob 2 1
John 1 1
Steve 1 0
This will do the trick in SQL Server:
SELECT
name,
SUM( CASE type WHEN 1 THEN 1 ELSE 0 END) AS type1,
SUM( CASE type WHEN 2 THEN 1 ELSE 0 END) AS type2
FROM
myTable
GROUP BY
name
No time to write the code, but the Case statement is what you want here. SImply havea value of 1 if it meets the case and zero if it deosn't. Then you can sum the columns.
Use two separate GROUP BY subqueries.
SELECT Name, a.Count1, b.Count2
from myTable
JOIN
(SELECT Name, SUM(Type) AS Count1 FROM myTable GROUP BY Name WHERE Type=1) AS a ON a.Name = myTable.Name
(SELECT Name, SUM(Type) FROM myTable GROUP BY Name WHERE Type=2) AS b ON b.Name = myTable.Name
You're looking for a CrossTab solution. The above solutions will work, but you'll come unstuck if you want a general solution and have N types.
A CrossTab solution will solve this for you. If this is for quickly crunching some numbers then dump your data into Excel and use the native Pivot Table feature.
If it's for a RDBMS in an app, then it depends upon the RDBMS. MS SQL 2005 and above has a crosstab syntax. See:
http://www.databasejournal.com/features/mssql/article.php/3521101/Cross-Tab-reports-in-SQL-Server-2005.htm
#Seb has a good solution, but it's server-dependent. Here's an alternate using subselects that should be portable:
select
name,
(select count(type) from myTable where type=1 and name=a.name) as type1,
(select count(type) from myTable where type=2 and name=a.name) as type2
from
myTable as a
group by
name