Show multiple colums with MAX in sql - sql

I am trying to write a query that shows the names of people with the highest salary in one of my tables.
Currently I have
SELECT MAX (salaris)
FROM (Technischdirecteur);
But this only shows a number and not the corresponding name to it. How would I go about adding the name of the person that has this salary?

Its Simple You can go with this way
And also you can choose the column you want to display by replacing the *
select *
From Technischdirecteur
Where salaris= (Select Max(salaris) From Technischdirecteur)

SELECT a.*, c.name
FROM Technischdirecteur a, club c
(SELECT MAX(salaris) salaris FROM Technischdirecteur) b
WHERE a.salaris = b.salaris
AND a.cl_id = c.cl_id

If you want all the values, don't think MAX(), think ORDER BY:
SELECT td.*
FROM Technischdirecteur td
ORDER BY salary desc
LIMIT 1;
Depending on the database, the LIMIT 1 could be FETCH FIRST 1 ROWS ONLY, TOP 1 (in the SELECT clause`, or even something else.

Related

How to use LIMIT and IN together to have a default row in SQL?

I am exploring SQL with W3School page and I have this requirements where I need to limit the query to a certain number but also having a default row included with that limit.
Here I want a default row where the customer name is Alfreds, then grab the remaining 29 rows to complete the query regardless of what their name is.
I tried to look on other SO question but they are too complicated to understand and using different syntax.
What you are looking for is a specific order clause.
Try this
SELECT * FROM Customers order by (case when CustomerName in ('Alfreds Futterkiste') then 0 else CustomerId end) limit 30 ;
If you're going to have a default row in SQL you should really have that row in the table with a known primary key, and then UNION it onto your query:
--default row, that is always included as long as the table has a PK 1
SELECT *
FROM Customers
WHERE CustomerId = 1
UNION ALL
--other rows, a variable number of
SELECT *
FROM Customers
WHERE CustomerId <> 1 AND ...
LIMIT 30
The limit presented in this way applies to the result of the Union
If you ever want to do something where you're unioning together limited sets in other combinations you might want to look at eg a form like
(... LIMIT 2)
UNION ALL
(... LIMIT 28)
Use UNION to combine the two queries.
SELECT *
FROM Customers
WHERE CustomerName != 'Alfredo Futterkiste'
LIMIT 9
UNION
SELECT *
FROM Customers
WHERE CustomerName = 'Alfreo Futterkiste'

Grab different column value after grouping by and aggregating a certain column

Let's say I have a table like so
CREATE TABLE Records (Event VARCHAR, Severity INT, Location VARCHAR)
I'd like to be able to grab the Event name and location of the row with the lowest severity. How could I achieve this?
Using top(1), limit(1) etc... you will get only one record with the lowest severity, but in case there are 2 of them you will lose the second.
I suggest you to use a nested query as follows:
from records r
where Severity = (
select min(severity)
from records
)
One simple method:
select top (1) r.*
from records r
order by r.severity;
If you want all rows in the event of ties, then use:
select top (1) with ties r.*

Group by question in SQL Server, migration from MySQL

Failed finding a solution to my problem, would love your help.
~~ Post has been edited to have only one question ~~-
Group by one query while selecting multiple columns.
In MySQL you can simply group by whatever you want, and it will still select all of them, so if for example I wanted to select the newest 100 transactions, grouped by Email (only get the last transaction of a single email)
In MySQL I would do that:
SELECT * FROM db.transactionlog
group by Email
order by TransactionLogId desc
LIMIT 100;
In SQL Server its not possible, googling a bit suggested to specify each column that I want to have with an aggregate as a hack, that couldn't cause a mix of values (mixing columns between the grouped rows)?
For example:
SELECT TOP(100)
Email,
MAX(ResultCode) as 'ResultCode',
MAX(Amount) as 'Amount',
MAX(TransactionLogId) as 'TransactionLogId'
FROM [db].[dbo].[transactionlog]
group by Email
order by TransactionLogId desc
TransactionLogId is the primarykey which is identity , ordering by it to achieve the last inserted.
Just want to know that the ResultCode and Amount that I'll get doing such query will be of the last inserted row, and not the highest of the grouped rows or w/e.
~Edit~
Sample data -
row1:
Email : test#email.com
ResultCode : 100
Amount : 27
TransactionLogId : 1
row2:
Email: test#email.com
ResultCode:50
Amount: 10
TransactionLogId: 2
Using the sample data above, my goal is to get the row details of
TransactionLogId = 2.
but what actual happens is that I get a mixed values of the two, as I do get transactionLogId = 2, but the resultcode and amount of the first row.
How do I avoid that?
Thanks.
You should first find out which is the latest transaction log by each email, then join back against the same table to retrieve the full record:
;WITH MaxTransactionByEmail AS
(
SELECT
Email,
MAX(TransactionLogId) as LatestTransactionLogId
FROM
[db].[dbo].[transactionlog]
group by
Email
)
SELECT
T.*
FROM
[db].[dbo].[transactionlog] AS T
INNER JOIN MaxTransactionByEmail AS M ON T.TransactionLogId = M.LatestTransactionLogId
You are currently getting mixed results because your aggregate functions like MAX() is considering all rows that correspond to a particular value of Email. So the MAX() value for the Amount column between values 10 and 27 is 27, even if the transaction log id is lower.
Another solution is using a ROW_NUMBER() window function to get a row-ranking by each Email, then just picking the first row:
;WITH TransactionsRanking AS
(
SELECT
T.*,
MostRecentTransactionLogRanking = ROW_NUMBER() OVER (
PARTITION BY
T.Email -- Start a different ranking for each different value of Email
ORDER BY
T.TransactionLogId DESC) -- Order the rows by the TransactionLogID descending
FROM
[db].[dbo].[transactionlog] AS T
)
SELECT
T.*
FROM
TransactionsRanking AS T
WHERE
T.MostRecentTransactionLogRanking = 1

how can I calculate the sum of my top n records in crystal report?

I m using report tab -> group sort expert-> top n to get top n record but i m getting sum of value in report footer for all records
I want only sum of value of top n records...
In below image i have select top 3 records but it gives sum of all records.
The group sort expert (and the record sort expert too) intervenes in your final result after the total summary is calculated. It is unable to filter and remove rows, in the same way an ORDER BY clause of SQL cannot effect the SELECT's count result (this is a job for WHERE clause). As a result, your summary will always be computed for all rows of your detail section and, of course, for all your group sums.
If you have in mind a specific way to exlude specific rows in order to appear the appropriate sum the you can use the Select Expert of Crystal Reports to remove rows.
Alternatively (and I believe this is the best way), I would make all the necessary calculations in the SQL command and I would sent to the report only the Top 3 group sums (then you can get what you want with a simple total summary of these 3 records)
Something like that
CREATE TABLE #TEMP
(
DEP_NAME varchar(50),
MINVAL int,
RMAVAL int,
NETVAL int
)
INSERT INTO #TEMP
SELECT TOP 3
T.DEP_NAME ,T.MINVAL,T.RMAVAL,T.NETVAL
FROM
(SELECT DEP_NAME AS DEP_NAME,SUM(MINVAL) AS MINVAL,SUM(RMAVAL) AS
RMAVAL,SUM(NETVAL) AS NETVAL
FROM YOURTABLE
GROUP BY DEP_NAME) AS T
ORDER BY MINVAL DESC
SELECT * FROM #TEMP

How do I check if all posts from a joined table has the same value in a column?

I'm building a BI report for a client where there is a 1-n related join involved.
The joined table has a field for employee ID (EmplId).
The query that I've built for this report is supposed to give a 1 in its field "OneEmployee" if all the related posts have the same employee in the EmplId field, null if it's different employees, i.e:
TaskTrans
TaskTransHours > EmplId: 'John'
TaskTransHours > EmplId: 'John'
This should give a 1 in the said field in the query
TaskTrans
TaskTransHours > EmplId: 'John'
TaskTransHours > EmplId: 'George'
This should leave the said field blank
The idea is to create a field where a case function checks this and returns the correct value. But my problem is whereas there is a way to check for this through SQL.
select not count(*) from your_table
where employee_id = GIVEN_ID
and your_field not in ( select min(your_field)
from your_table
where employee_id = GIVEN_ID);
Note: my first idea was to use LIMIT 1 in the inner query, but MYSQL didn't like it, so min it was - the points to use any, but only one. Min should work, but the field should be indexed, then this query will actually execute rather fast, as only indexes would be used (obviously employee_id should also be indexed).
Note2: Do not get too confused with not in front of count(*), you want 1 when there is none that is different, I count different ones, and then give you the not count(*), which will be one if count is 0, otherwise 0.
Seems a job for a window COUNT():
SELECT
…,
CASE COUNT(DISTINCT TaskTransHours.EmplId) OVER () WHEN 1 THEN 1 END
AS OneEmployee
FROM …