Have a query that uses double select (with select max) to fetch the row with the latest 'calculation_time' column among multiple rows which can have the same 'patient_set_id'. If there are multiple rows with the same 'patient_set_id', only the row with the latest 'calculation_time' should be retrieved. Calculation time is a date.
So far I've tried this but I'm not really sure if there is any better way for this, maybe using ORDER BY. But I'm very new to sql and need to know which one would be the fastest and more appropriate?
SELECT median from diagnostic_risk_stats WHERE
calculation_time=(SELECT MAX(calculation_time) FROM diagnostic_risk_stats WHERE
patient_set_id = UNHEX(REPLACE('5a9dbfca-74d6-471a-af27-31beb4b53bb2', "-","")));
You can use not exists as follows:
SELECT median
from diagnostic_risk_stats t
WHERE not exists
(Select 1 from diagnostic_risk_stats tt
Where t.patient_set_id = tt.patient_set_id
And tt.calculation_time > t.calculation_time)
And t.patient_set_id = UNHEX(REPLACE('5a9dbfca-74d6-471a-af27-31beb4b53bb2', "-",""));
Related
I am attempting to filter my table and get the item that sold for the most amount of money. In order to do this I am using "AuctionOpen" to determine whether or not the auction is still open. The auction cannot be open and have the item been sold (later I will use this for the most expensive item available).
I am able to use the AND operator to compare AuctionOpen by using the following:
select s.*
from auctionsite.dbo.Auction s
where s.HighestBid = (select max(s2.HighestBid) from auctionsite.dbo.Auction
s2) and s.AuctionOpen = 0;
When I set this equal to zero I get results, but when I set it equal to 1, it only returns the column titles even though there are values set to 1 in the table.
Results when compared to 0:
Results when compared to 1:
Clearly, the highest bid is on a record where AuctionOpen <> 1.
I recommend using order by and fetch (or the equivalent in your database):
select s.*
from auctionsite.dbo.Auction s
where s.AuctionOpen = 0
order by s.HIghestBid desc
fetch first 1 row only
In SQL Server, use either select top (1) or offset 0 rows fetch first 1 row only.
I think you should try the Count aggregate function
here, try this:
**Select count(Item_name) As
[Item with the highest money]
from table_name
Group by Item_name DSEC;**
You can check my page hereSQL/MySQL tips for some SQL/MySQL lessons
I need to figure out how to eliminate older revisions from my query's results, my database stores orders as 'Q000000' and revisions have an appended '-number'. My query currently is as follows:
SELECT DISTINCT Estimate.EstimateNo
FROM Estimate
INNER JOIN EstimateDetails ON EstimateDetails.EstimateID = Estimate.EstimateID
INNER JOIN EstimateDoorList ON EstimateDoorList.ItemSpecID = EstimateDetails.ItemSpecID
WHERE (Estimate.SalesRepID = '67' OR Estimate.SalesRepID = '61') AND Estimate.EntryDate >= '2017-01-01 00:00:00.000' AND EstimateDoorList.SlabSpecies LIKE '%MDF%'
ORDER BY Estimate.EstimateNo
So for instance, the results would include:
Q120455-10
Q120445-11
Q121675-2
Q122361-1
Q123456
Q123456-1
From this, I need to eliminate 'Q120455-10' because of the presence of '-11' for that order, and 'Q123456' because of the presence of the '-1' revision. I'm struggling greatly with figuring out how to do this, my immediate thought was to use case statements but I'm not sure what is the best way to implement them and how to filter. Thank you in advance, let me know if any more information is needed.
First you have to parse your EstimateNo column into sequence number and revision number using CHARINDEX and SUBSTRING (or STRING_SPLIT in newer versions) and CAST/CONVERT the revision to a numeric type
SELECT
SUBSTRING(Estimate.EstimateNo,0,CHARINDEX('-',Estimate.EstimateNo)) as [EstimateNo],
CAST(SUBSTRING(Estimate.EstimateNo,CHARINDEX('-',Estimate.EstimateNo)+1, LEN(Estimate.EstimateNo)-CHARINDEX('-',Estimate.EstimateNo)+1) as INT) as [EstimateRevision]
FROM
...
You can then use
APPLY - to select TOP 1 row that matches the EstimateNo or
Window function such as ROW_NUMBER to select only records with row number of 1
For example, using a ROW_NUMBER would look something like below:
SELECT
ROW_NUMBER() OVER(PARTITION BY EstimateNo ORDER BY EstimateRevision DESC) AS "LastRevisionForEstimate",
-- rest of the needed columns
FROM
(
-- query above goes here
)
You can then wrap the query above in a simple select with a where predicate filtering out a specific value of LastRevisionForEstimate, for instance
SELECT --needed columns
FROM -- result set above
WHERE LastRevisionForEstimate = 1
Please note that this is to a certain extent, pseudocode, as I do not have your schema and cannot test the query
If you dislike the nested selects, check out the Common Table Expressions
I need to write a query in sql and I can't do it correctly. I have a table with 7 columns 1st_num, 2nd_num, 3rd_num, opening_Date, Amount, code, cancel_Flag.
For every 1st_num, 2nd_num, 3rd_num I want to take only the record with the min (cancel_flag), and if there's more then 1 row so take the the newest opening Date.
But when I do group by and choose min and max for the relevant fields, I get a mix of the rows, for example:
1. 12,130,45678,2015-01-01,2005,333,0
2. 12,130,45678,2015-01-09,105,313,0
The result will be
:12,130,45678,2015-01-09,2005,333,0
and that mixes the rows into one
Microsoft sql server 2008 . using ssis by visual studio 2008
my code is :
SELECT
1st_num,
2nd_num,
3rd_num,
MAX(opening_date),
MAX (Amount),
code,
MIN(cancel_flag)
FROM do. tablename
GROUP BY
1st_num,
2nd_num,
3rd_num,
code
HAVING COUNT(*) > 1
How do I take the row with the max date or.min cancel flag as it is without mixing values?
I can't really post my code because of security reasons but I'm sure you can help.
thank you,
Oren
It is very difficult like this to answer, because every DBMS has different syntax.
Anyways, for most dbms this should work. Using row_number() function to rank the rows, and take only the first one by our definition (all your conditions):
SELECT * FROM (
SELECT t.*,
ROW_NUMBER() OVER ( PARTITION BY t.1st_num,t.2nd_num,t.3rd_num order by t.cancel_flag asc,t.opening_date desc) as row_num
FROM YourTable t ) as tableTempName
WHERE row_num = 1
Use NOT EXISTS to return a row as long as no other row with same 1st_num, 2nd_num, 3rd_num has a lower cancel_flag value, or same cancel_flag but a higher opening_Date.
select *
from tablename t1
where not exists (select 1 from tablename t2
where t2.1st_num = t1.1st_num
and t2.2nd_num = t1.2nd_num
and t2.3rd_num = t1.3rd_num
and (t2.cancel_flag < t1.cancel_flag
or (t2.cancel_flag = t1.cancel_flag and
t2.opening_Date > t1.opening_Date)))
Core ANSI SQL-99, expected to work with (almost) any dbms.
I need to compare current row and previous row and based on some comparision need to derive a column value. Currently apporach I m following is making two differnt record sets and then use rank function and then by joining rank functions I m able to achiieve this. However, this seems to be tedious apporach, is there a better way to achieve this. I m currently writing query something like below :-
select
< comparing columns from two record sets and deriving column value>
(
select(<some complex logic>, rank from a) rcdset,
(select <some complex logic>, rank +1 from a) rcdset2 where rcdset.rnk = rcdset1.rnk (+)
Database - Oracle 10g
Use LAG(value_expr) OVER (ORDER BY rank_col) to retrieve the value (value_expr) from previous row (order defined by rank_col), see http://oracle-base.com/articles/misc/lag-lead-analytic-functions.php
I have the below query. The problem is the last column productdesc is returning two records and the query fails because of distinct. Now i need to add one more column in where clause of the select query so that it returns one record. The issue is that the column i need
to add should not be a part of group by clause.
SELECT product_billing_id,
billing_ele,
SUM(round(summary_net_amt_excl_gst/100)) gross,
(SELECT DISTINCT description
FROM RES.tariff_nt
WHERE product_billing_id = aa.product_billing_id
AND billing_ele = aa.billing_ele) productdescr
FROM bil.bill_sum aa
WHERE file_id = 38613 --1=1
AND line_type = 'D'
AND (product_billing_id, billing_ele) IN (SELECT DISTINCT
product_billing_id,
billing_ele
FROM bil.bill_l2 )
AND trans_type_desc <> 'Change'
GROUP BY product_billing_id, billing_ele
I want to modify the select statement to the below way by adding a new filter to the where clause so that it returns one record .
(SELECT DISTINCT description
FROM RRES.tariff_nt
WHERE product_billing_id = aa.product_billing_id
AND billing_ele = aa.billing_ele
AND (rate_structure_start_date <= TO_DATE(aa.p_effective_date,'yyyymmdd')
AND rate_structure_end_date > TO_DATE(aa.p_effective_date,'yyyymmdd'))
) productdescr
The aa.p_effective_date should not be a part of GROUP BY clause. How can I do it? Oracle is the Database.
So there are multiple RES.tariff records for a given product_billing_id/billing_ele, differentiated by the start/end dates
You want the description for the record that encompasses the 'p_effective_date' from bil.bill_sum. The kicker is that you can't (or don't want to) include that in the group by. That suggests you've got multiple rows in bil.bill_sum with different effective dates.
The issue is what do you want to happen if you are summarising up those multiple rows with different dates. Which of those dates do you want to use as the one to get the description.
If it doesn't matter, simply use MIN(aa.p_effective_date), or MAX.
Have you looked into the Oracle analytical functions. This is good link Analytical Functions by Example