I know there has been a lot of discussion around this subject but I cannot find anything that points me in the direction of a definitive answer.
I have the below sql statement within a .net page in Webmatrix:
SELECT vehicle, vehicleDescription, count(vehicleDescription) AS 'Total'
FROM vehicles
WHERE (branchRequirement = 'Manchester')
AND (deliveryBranch = 'Manchester' OR deliveryBranch IS NULL)
AND (dateDeliveredToBranch > GETDATE() OR dateDeliveredToBranch IS NULL)
AND (vgc LIKE 'B_') GROUP BY vehicle,vehicleDescription
The output is obviously GROUPED data for the chosen conditions.
What I am trying to do is provide a link in my Webgrid on the .net page which allows the user to open a child page with details of the GROUPED vehicles.
Where I'm getting stuck is I cannot include the vehicleID in the GROUP BY because they are obviously all UNIQUE.
Has anybody come across this or something similar with any degree of success as I am pulling my hair out with it which I can ill afford to do!
Thanks
M
I have come across similar issues and the solution I came up with was to use the information you already have. When the user clicks on the link, you know the vehicle and the vehicleDescription that the user wants to see. You should not need the vehicleId because you are not going to have one unique result. If they click on a vehicle that has a count of 3, the child page should have details about all 3 results.
In order to find the 3 results the user would want to see, you can alter your existing query and use it for the child page. The altered query should take the vehicle and vehicleDesciption as parameters.
SELECT *
FROM vehicles
WHERE (branchRequirement = 'Manchester')
AND (deliveryBranch = 'Manchester' OR deliveryBranch IS NULL)
AND (dateDeliveredToBranch > GETDATE() OR dateDeliveredToBranch IS NULL)
AND (vgc LIKE 'B_')
AND vehicle = #vehicle
AND vehicleDesciption = #vehicleDescription
Pass the parameters in .Net and you should end up with the same data that you summed in your last query, since this query is essentially the same.
Related
Schema
Question: List all paying customers with users who had 4 or 5 activities during the week of February 15, 2021; also include how many of the activities sent were paid, organic and/or app store. (i.e. include a column for each of the three source types).
My attempt so far:
SELECT source_type, COUNT(*)
FROM activities
WHERE activity_time BETWEEN '02-15-21' AND '02-19-21'
GROUP BY source_type
I would like to get a second opinion on it. I didn't include the accounts table because I don't believe that I need it for this query, but I could be wrong.
Have you tried to run this? It doesn't satisfy the brief on FOUR counts:
List all the ... customers (that match criteria)
There is no customer information included in the results at all, so this is an outright fail.
paying customers
This is the top level criteria, only customers that are not free should be included in the results.
Criteria: users who had 4 or 5 activities
There has been no attempt to evaluate this user criteria in the query, and the results do not provide enough information to deduce it.
there is further ambiguity in this requirement, does it mean that it should only include results if the account has individual users that have 4 or 5 acitvities, or is it simply that the account should have 4 or 5 activities overall.
If this is a test question (clearly this is contrived, if it is not please ask for help on how to design a better schema) then the use of the term User is usually very specific and would suggest that you need to group by or otherwise make specific use of this facet in your query.
Bonus: (i.e. include a column for each of the three source types).
This is the only element that was attempted, as the data is grouped by source_type but the information cannot be correlated back to any specific user or customer.
Next time please include example data and the expected outcome with your post. In preparing the data for this post you would have come across these issues yourself and may have been inspired to ask a different question, or through the process of writing the post up you may have resolved the issue yourself.
without further clarification, we can still start to evolve this query, a good place to start is to exclude the criteria and focus on the format of the output. the requirement mentions the following output requirements:
List Customers
Include a column for each of the source types.
Firstly, even though you don't think you need to, the request clearly states that Customer is an important facet in the output, and in your schema account holds the customer information, so although we do not need to, it makes the data readable by humans if we do include information from the account table.
This is a standard PIVOT style response then, we want a row for each customer, presenting a count that aggregates each of the values for source_type. Most RDBMS will support some variant of a PIVOT operator or function, however we can achieve the same thing with simple CASE expressions to conditionally put a value into projected columns in the result set that match the values we want to aggregate, then we can use GROUP BY to evaluate the aggregation, in this case a COUNT
The following syntax is for MS SQL, however you can achieve something similar easily enough in other RBDMS
OP please tag this question with your preferred database engine...
NOTE: there is NO filtering in this query... yet
SELECT accounts.company_id
, accounts.company_name
, paid = COUNT(st_paid)
, organic = COUNT(st_organic)
, app_store = COUNT(st_app_store)
FROM activities
INNER JOIN accounts ON activities.company_id = accounts.company_id
-- PIVOT the source_type
CROSS APPLY (SELECT st_paid = CASE source_type WHEN 'paid' THEN 1 END
,st_organic = CASE source_type WHEN 'organic' THEN 1 END
,st_app_store = CASE source_type WHEN 'app store' THEN 1 END
) as PVT
GROUP BY accounts.company_id, accounts.company_name
This results in the following shape of result:
company_id
company_name
paid
organic
app_store
apl01
apples
4
8
0
ora01
oranges
6
12
0
Criteria
When you are happy with the shpe of the results and that all the relevant information is available, it is time to apply the criteria to filter this data.
From the requirement, the following criteria can be identified:
paying customers
The spec doesn't mention paying specifically, but it does include a note that (free customers have current_mrr = 0)
Now aren't we glad we did join on the account table :)
users who had 4 or 5 activities
This is very specific about explicitly 4 or 5 activities, no more, no less.
For the sake of simplicity, lets assume that the user facet of this requirement is not important and that is is simply a reference to all users on an account, not just users who have individually logged 4 or 5 activities on their own - this would require more demo data than I care to manufacture right now to prove.
during the week of February 15, 2021.
This one was correctly identified in the original post, but we need to call it out just the same.
OP has used Monday to Friday of that week, there is no mention that weeks start on a Monday or that they end on Friday but we'll go along, it's only the syntax we need to explore today.
In the real world the actual values specified in the criteria should be parameterised, mainly because you don't want to manually re-construct the entire query every time, but also to sanitise input and prevent SQL injection attacks.
Even though it seems overkill for this post, using parameters even in simple queries helps to identify the variable elements, so I will use parameters for the 2nd criteria to demonstrate the concept.
DECLARE #from DateTime = '2021-02-15' -- Date in ISO format
DECLARE #to DateTime = (SELECT DateAdd(d, 5, #from)) -- will match Friday: 2021-02-19
/* NOTE: requirement only mentioned the start date, not the end
so your code should also only rely on the single fixed start date */
SELECT accounts.company_id, accounts.company_name
, paid = COUNT(st_paid), organic = COUNT(st_organic), app_store = COUNT(st_app_store)
FROM activities
INNER JOIN accounts ON activities.company_id = accounts.company_id
-- PIVOT the source_type
CROSS APPLY (SELECT st_paid = CASE source_type WHEN 'paid' THEN 1 END
,st_organic = CASE source_type WHEN 'organic' THEN 1 END
,st_app_store = CASE source_type WHEN 'app store' THEN 1 END
) as PVT
WHERE -- paid accounts = exclude 'free' accounts
accounts.current_mrr > 0
-- Date range filter
AND activity_time BETWEEN #from AND #to
GROUP BY accounts.company_id, accounts.company_name
-- The fun bit, we use HAVING to apply a filter AFTER the grouping is evaluated
-- Wording was explicitly 4 OR 5, not BETWEEN so we use IN for that
HAVING COUNT(source_type) IN (4,5)
I believe you are missing some information there.
without more information on the tables, I can only guess that you also have a customer table. i am going to assume there is a customer_id key that serves as key between both tables
i would take your query and do something like:
SELECT customer_id,
COUNT() AS Total,
MAX(CASE WHEN source_type = "app" THEN "numoperations" END) "app_totals"),
MAX(CASE WHEN source_type = "paid" THEN "numoperations" END) "paid_totals"),
MAX(CASE WHEN source_type = "organic" THEN "numoperations" END) "organic_totals"),
FROM (
SELECT source_type, COUNT() AS num_operations
FROM activities
WHERE activity_time BETWEEN '02-15-21' AND '02-19-21'
GROUP BY source_type
) tb1 GROUP BY customer_id
This is the most generic case i can think of, but does not scale very well. If you get new source types, you need to modify the query, and the structure of the output table also changes. Depending on the sql engine you are using (i.e. mysql vs microsoft sql) you could also use a pivot function.
The previous query is a little bit rough, but it will give you a general idea. You can add "ELSE" statements to the clause, to zero the fields when they have no values, and join with the customer table if you want only active customers, etc.
As part of my course in university I have to make a database in Microsoft Access which is somewhat limiting me on what I'm trying to do. I have a table that has the information of whether a player in a team was present for a fixture or not using the values "P", "R", and "M" (Played, Reserves, Missed). I want to make a query that counts a value of 1 for each value of P or R and a separate one for M, so that when I make a report that prints off a membership card, it shows the amount of fixtures they've played in and the amount of fixtures that they have missed.
Sorry if this isn't clear, I'll try to explain myself further if you ask but I'm not very good with this stuff. Thank you.
Edit: I'll use screenshot links if that's okay, here is the Fixture Attendance entity that shows if a member of a team attended a game or not. I'm making a membership card based off this one. I want to be able to display the No. of fixtures played by the member and the No. of fixtures missed based off the values in the above entity and use that information in a form I'm going to create. That will be a subform inside my Membership Card form.
I'm presumably really bad at explaining this - I understand Access is rarely used in the real world so I'm not sure why I'm doing this in the first place and don't feel like I'm getting any real knowledge of working with databases.
You should use the COUNT function.
http://office.microsoft.com/en-us/access-help/count-data-by-using-a-query-HA010096311.aspx
I am guessing that you want something like this:
select playerid, sum(iif(fixture in ("P", "R"), 1, 0)) as NumPR,
sum(iif(figure = "M", 1, 0)as NumM
from table t
group by playerid;
The key idea here is putting the conditional part (iif()) inside the sum().
CASE WHEN can be used to translate the codes into 1's and 0's. Then use SUM with a GROUP BY to sum them.
SELECT player_id, SUM(Played), SUM(Reserve), SUM(Missed)
FROM
(SELECT player_id,
CASE WHEN present = 'P' THEN 1 ELSE 0 AS Played,
CASE WHEN present = 'R' THEN 1 ELSE 0 AS Reserve,
CASE WHEN present = 'M' THEN 1 ELSE 0 AS Missed
FROM fixtures)
GROUP BY player_id;
I'm running SQL queries in Orion Report Writer for Solarwinds Netflow Traffic Analyzer and am trying to add up data usage for specific conversations coming from the same general sources. In this case it is netflix. I've made some progress with my query.
SELECT TOP 10000 FlowCorrelation_Source_FlowCorrelation.FullHostname AS Full_Hostname_A,
SUM(NetflowConversationSummary.TotalBytes) AS SUM_of_Bytes_Transferred,
SUM(NetflowConversationSummary.TotalBytes) AS Total_Bytes
FROM
((NetflowConversationSummary LEFT OUTER JOIN FlowCorrelation FlowCorrelation_Source_FlowCorrelation ON (NetflowConversationSummary.SourceIPSort = FlowCorrelation_Source_FlowCorrelation.IPAddressSort)) LEFT OUTER JOIN FlowCorrelation FlowCorrelation_Dest_FlowCorrelation ON (NetflowConversationSummary.DestIPSort = FlowCorrelation_Dest_FlowCorrelation.IPAddressSort)) INNER JOIN Nodes ON (NetflowConversationSummary.NodeID = Nodes.NodeID)
WHERE
( DateTime BETWEEN 41539 AND 41570 )
AND
(
(FlowCorrelation_Source_FlowCorrelation.FullHostname LIKE 'ipv4_1.lagg0%')
)
GROUP BY FlowCorrelation_Source_FlowCorrelation.FullHostname, FlowCorrelation_Dest_FlowCorrelation.FullHostname, Nodes.Caption, Nodes.NodeID, FlowCorrelation_Source_FlowCorrelation.IPAddress
So I've got an output that filters everything but netflix sessions (Full_Hostname_A) and their total usage for each session (Sum_Of_Bytes_Transferred)
I want to add up Sum_Of_Bytes_Transferred to get a total usage for all netflix sessions
listed, which will output to Total_Bytes. I created the column Total_Bytes, but don't know how to output a total to it.
For some asked clarification, here is the output from the above query:
I want the Total_Bytes Column to be all added up into one number.
I have no familiarity with the reporting tool you are using.
From reading your post I'm thinking you want the the first 2 columns of data that you've got, plus at a later point in the report, a single figure being the sum of the total_bytes column you're already producing.
Your reporting tool probably has some means of totalling a column, but you may need to get the support people for the reporting tool to tell you how to do that.
Aside from this, if you can find a way of calling a separate query in a latter section of the report, or if you embed a new report inside your existing report, after the detail section, and use that to run a separate query then you should be able to get the data you want with this:
SELECT Sum(Total_Bytes) as [Total Total Bytes]
FROM ( yourExistingQuery ) x
yourExistingQuery means the query you've already got, in full (doesnt have to be put on one line), the paretheses are required, and so is the "x". (The latter provides a syntax-required name for the virtual table which your query defines).
Hope this helps.
Okay, I'm using WordPress, but this pertains to the SQL side.
I have a query in which I need to filter out posts using three different categories, but they're all terms in the post.
For example:
In my three categories, I select the following: (Academia,Webdevelopment) (Fulltime,Parttime) (Earlycareer).
Now what I want to do is make sure when I query that the post has AT LEAST ONE of each of those terms.
CORRECT RESULT: A post with tags Academia, Fulltime, Earlycareer
INCORRECT RESULT: A post with tags Academia, Earlycareer (doesn't have fulltime or parttime)
Currently, my query looks something like this:
SELECT * FROM $wpdb->posts WHERE
(
$wpdb->terms.slug IN (list of selected from category 1) AND
$wpdb->terms.slug IN (list of selected from category 2) AND
$wpdb->terms.slug IN (list of selected from category 3)
)
AND $wpdb->term_taxonomy.taxonomy = 'jobtype' AND .......
When using this query, it returns no results when I select across the different categories (that is, I can choose 4 things from category 1 and it has results, but I can't choose anything from category 2 or 3. And vice versa)
I'm not sure if this is something to do with using IN more than once on the same column.
Thanks in advance for any help!
Your query seems to be correct. There is no any limitations in SQL about using IN for the same column miltimple times.
But ensure that you don't have any NULL values in your list of selected from category 1/2/3 queries. Even single NULL value in these lists will give NULL as a result of whole 'WHERE' condition and you will get nothing as a result.
If this won't help then it must be WordPress issue.
I'm developing an online gallery with voting and have a separate table for pictures and votes (for every vote I'm storing the ID of the picture and the ID of the voter). The tables related like this: PICTURE <--(1:n, using VOTE.picture_id)-- VOTE. I would like to query the pictures table and sort the output by votes number. This is what I do:
SELECT
picture.votes_number,
picture.creation_date,
picture.author_id,
picture.author_nickname,
picture.id,
picture.url,
picture.name,
picture.width,
picture.height,
coalesce(anon_1."totalVotes", 0)
FROM picture
LEFT OUTER JOIN
(SELECT
vote.picture_id as pid,
count(*) AS "totalVotes"
FROM vote
WHERE vote.device_id = <this is the query parameter> GROUP BY pid) AS anon_1
ON picture.id = anon_1.pid
ORDER BY picture.votes_number DESC
LIMIT 10
OFFSET 0
OFFSET is different for different pages, of course.
However, there are pictures with the same ID that are displayed on the different pages. I guess the reason is the sorting, but can't construct any better query, which will not allow duplicates. Could anybody give me a hint?
Thanks in advance!
Do you execute one query per page to display? If yes, I suspect that the database doesn't guarantee a consitent order for items with the same number of votes. So first query may return { item 1, item 2 } and a 2nd query may return { item 2, item 1} if both items have same number of votes. If the items are actually items 10 and 11, then the same item may appear on page 1 and then on page 2.
I had such a problem once. If that's also your case, append an extra clause to the order by to ensure a consistent ordering of items with same vote number, e.g.:
ORDER BY picture.vote, picture.ID
The simples explanation is that you had some data added or some votes occured when you was looking at different pages.
I am sure if you would sorte by ID or creation_date this issue would go away.
I.e. there is no issue with your code
in my case this problem was due to the Null value in the Order By clause, i solved this by adding another Unique ID field in Order By Clause along with other field.