There is a table where user_id is for each test taker, and choice is the answer for all the three questions. I would like to get all the different sequence of choices that test taker made and count the sequence. Is there a way to write sql query to achieve this? Thanks
----------------------------------
| user_id | Choice |
----------------------------------
| 1 | a |
----------------------------------
| 1 | b |
----------------------------------
| 1 | c |
----------------------------------
| 2 | b |
----------------------------------
| 2 | c |
----------------------------------
| 2 | a |
----------------------------------
Desire answer:
----------------------------------
| choice | count |
----------------------------------
| a,b,c | 1 |
----------------------------------
| b,c,a | 1 |
-----------------------------------
In BigQuery, you can use aggregation functions:
select choices, count(*)
from (select string_agg(choice order by ?) as choices, user_id
from t
group by user_id
) t
group by choices;
The ? is for the column that specifies the ordering of the table. Remember: tables represent unordered sets, so without such a column the choices can be in any order.
You can do something similar in SQL Server 2017+ using string_agg(). In earlier versions, you have to use an XML method, which is rather unpleasant.
Related
I have a table with the following structure and data in it:
| ID | Date | Result |
|---- |------------ |-------- |
| 1 | 30/04/2020 | + |
| 1 | 01/05/2020 | - |
| 1 | 05/05/2020 | - |
| 2 | 03/05/2020 | - |
| 2 | 04/05/2020 | + |
| 2 | 05/05/2020 | - |
| 2 | 06/05/2020 | - |
| 3 | 01/05/2020 | - |
| 3 | 02/05/2020 | - |
| 3 | 03/05/2020 | - |
| 3 | 04/05/2020 | - |
I'm trying to write an SQL query (I'm using SQL Server) which returns the date of the first two consecutive negative results for a given ID.
For example, for ID no. 1, the first two consecutive negative results are on 01/05 and 05/05.
The first two consecutive results for ID No. 2 are on 05/05 and 06/05.
The first two consecutive negative results for ID No. 3 are on on 01/05 and 02/05 .
So the query should produce the following result:
| ID | FirstNegativeDate |
|---- |------------------- |
| 1 | 01/05 |
| 2 | 05/05 |
| 3 | 01/05 |
Please note that the dates aren't necessarily one day apart. Sometimes, two consecutive negative tests may be several days apart. But they should still be considered as "consecutive negative tests". In other words, two negative tests are not 'consecutive' only if there is a positive test result in between them.
How can this be done in SQL? I've done some reading and it looks like maybe the PARTITION BY statement is required but I'm not sure how it works.
This is a gaps-and-island problem, where you want the start of the first island of '-'s that contains at least two rows.
I would recommend lead() and aggregation:
select id, min(date) first_negative_date
from (
select t.*, lead(result) over(partition by id order by date) lead_result
from mytable t
) t
where result = '-' and lead_result = '-'
group by id
Use LEAD or LAG functions over ID partition ordered by your Date column.
Then simple check where LEAD/LAG column is equal to Result.
You'll need also to filter the top ones.
The image attached just shows what LEAD/LAG would return
I have a Production Table and a Standing Data table. The relationship of Production to Standing Data is actually Many-To-Many which is different to how this relationship is usually represented (Many-to-One).
The standing data table holds a list of tasks and the score each task is worth. Tasks can appear multiple times with different "ValidFrom" dates for changing the score at different points in time. What I am trying to do is query the Production Table so that the TaskID is looked up in the table and uses the date it was logged to check what score it should return.
Here's an example of how I want the data to look:
Production Table:
+----------+------------+-------+-----------+--------+-------+
| RecordID | Date | EmpID | Reference | TaskID | Score |
+----------+------------+-------+-----------+--------+-------+
| 1 | 27/02/2020 | 1 | 123 | 1 | 1.5 |
| 2 | 27/02/2020 | 1 | 123 | 1 | 1.5 |
| 3 | 30/02/2020 | 1 | 123 | 1 | 2 |
| 4 | 31/02/2020 | 1 | 123 | 1 | 2 |
+----------+------------+-------+-----------+--------+-------+
Standing Data
+----------+--------+----------------+-------+
| RecordID | TaskID | DateActiveFrom | Score |
+----------+--------+----------------+-------+
| 1 | 1 | 01/02/2020 | 1.5 |
| 2 | 1 | 28/02/2020 | 2 |
+----------+--------+----------------+-------+
I have tried the below code but unfortunately due to multiple records meeting the criteria, the production data duplicates with two different scores per record:
SELECT p.[RecordID],
p.[Date],
p.[EmpID],
p.[Reference],
p.[TaskID],
s.[Score]
FROM ProductionTable as p
LEFT JOIN StandingDataTable as s
ON s.[TaskID] = p.[TaskID]
AND s.[DateActiveFrom] <= p.[Date];
What is the correct way to return the correct and singular/scalar Score value for this record based on the date?
You can use apply :
SELECT p.[RecordID], p.[Date], p.[EmpID], p.[Reference], p.[TaskID], s.[Score]
FROM ProductionTable as p OUTER APPLY
( SELECT TOP (1) s.[Score]
FROM StandingDataTable AS s
WHERE s.[TaskID] = p.[TaskID] AND
s.[DateActiveFrom] <= p.[Date]
ORDER BY S.DateActiveFrom DESC
) s;
You might want score basis on Record Level if so, change the where clause in apply.
I was looking to provide an answer to this question in which the OP has two tables:
Table1
+--------+--------+
| testID | Status |
+--------+--------+
| 1 | |
| 2 | |
| 3 | |
+--------+--------+
Table2
+----+--------+--------+--------+
| ID | testID | stepID | status |
+----+--------+--------+--------+
| 1 | 1 | 1 | pass |
| 2 | 1 | 2 | fail |
| 3 | 1 | 3 | pass |
| 4 | 2 | 1 | pass |
| 5 | 2 | 2 | pass |
| 6 | 3 | 1 | fail |
+----+--------+--------+--------+
Here, the OP is looking to update the status field for each testID in Table1 with pass if the status of all stepID records associated with the testID in Table2 have a status of pass, else Table1 should be updated with fail for that testID.
In this example, the result should be:
+--------+--------+
| testID | Status |
+--------+--------+
| 1 | fail |
| 2 | pass |
| 3 | fail |
+--------+--------+
I wrote the following SQL code in an effort to accomplish this:
update Table1 a inner join
(
select
b.testID,
iif(min(b.status)=max(b.status) and min(b.status)='pass','pass','fail') as v
from Table2 b
group by b.testID
) c on a.testID = c.testID
set a.testStatus = c.v
However, MS Access reports the all-too-familiar, 'operation must use an updateable query' response.
I know that a query is not updateable if there is a one-to-many relationship between the record being updated and the set of values, but in this case, the aggregated subquery would yield a one-to-one relationship between the two testID fields.
Which left me asking, why is this query not updateable?
You're joining in a query with an aggregate (Max).
Aggregates are not updateable. In Access, in an update query, every part of the query has to be updateable (with the exception of simple expressions, and subqueries in WHERE part of your query), which means your query is not updateable.
You can work around this by using domain aggregates (DMin and DMax) instead of real ones, but this query will take a large performance hit if you do.
You can also work around it by rewriting your aggregates to take place in an EXISTS or NOT EXISTS clause, since that's part of the WHERE clause thus doesn't need to be updateable. That would likely minimally affect performance, but means you have to split this query in two: 1 query to set all the fields to "pass" that meet your condition, another to set them to "fail" if they don't.
I have data on approx 1000 individuals, where each individual can have multiple rows, with multiple dates and where the columns indicate the program admitted to and a code number.
I need each row to contain a distinct date, so I need to delete the rows of duplicate dates from my table. Where there are multiple rows with the same date, I need to keep the row that has the lowest code number. In the case of more than one row having both the same date and the same lowest code, then I need to keep the row that also has been in program (prog) B. For example;
| ID | DATE | CODE | PROG|
--------------------------------
| 1 | 1996-08-16 | 24 | A |
| 1 | 1997-06-02 | 123 | A |
| 1 | 1997-06-02 | 123 | B |
| 1 | 1997-06-02 | 211 | B |
| 1 | 1997-08-19 | 67 | A |
| 1 | 1997-08-19 | 23 | A |
So my desired output would look like this;
| ID | DATE | CODE | PROG|
--------------------------------
| 1 | 1996-08-16 | 24 | A |
| 1 | 1997-06-02 | 123 | B |
| 1 | 1997-08-19 | 23 | A |
I'm struggling to come up with a solution to this, so any help greatly appreciated!
Microsoft SQL Server 2012 (X64)
The following works with your test data
SELECT ID, date, MIN(code), MAX(prog) FROM table
GROUP BY date
You can then use the results of this query to create a new table or populate a new table. Or to delete all records not returned by this query.
SQLFiddle http://sqlfiddle.com/#!9/0ebb5/5
You can use min() function: (See the details here)
select ID, DATE, min(CODE), max(PROG)
from table
group by DATE
I assume that your table has a valid primary key. However i would recommend you to take IDas Primary key. Hope this would help you.
I'm sure this has been asked but I can't quite find the right search terms.
Given a schema like this:
| CarMakeID | CarMake
------------------------
| 1 | SuperCars
| 2 | MehCars
| CarMakeID | CarModelID | CarModel
-----------------------------------------
| 1 | 1 | Zoom
| 2 | 1 | Wow
| 3 | 1 | Awesome
| 4 | 2 | Mediocrity
| 5 | 2 | YoureSettling
I want to produce a dataset like this:
| CarMakeID | CarMake | CarModels
---------------------------------------------
| 1 | SuperCars | Zoom, Wow, Awesome
| 2 | MehCars | Mediocrity, YoureSettling
What do I do in place of 'AGG' for strings in SQL Server in the following style query?
SELECT *,
(SELECT AGG(CarModel)
FROM CarModels model
WHERE model.CarMakeID = make.CarMakeID
GROUP BY make.CarMakeID) as CarMakes
FROM CarMakes make
http://www.simple-talk.com/sql/t-sql-programming/concatenating-row-values-in-transact-sql/
It is an interesting problem in Transact SQL, for which there are a number of solutions and considerable debate. How do you go about producing a summary result in which a distinguishing column from each row in each particular category is listed in a 'aggregate' column? A simple, and intuitive way of displaying data is surprisingly difficult to achieve. Anith Sen gives a summary of different ways, and offers words of caution over the one you choose...
If it is SQL Server 2017 or SQL Server VNext, Azure SQL database you can use String_agg as below:
SELECT make.CarMakeId, make.CarMake,
CarModels = string_agg(model.CarModel, ', ')
FROM CarModels model
INNER JOIN CarMakes make
ON model.CarMakeId = make.CarMakeId
GROUP BY make.CarMakeId, make.CarMake
Output:
+-----------+-----------+---------------------------+
| CarMakeId | CarMake | CarModels |
+-----------+-----------+---------------------------+
| 1 | SuperCars | Zoom, Wow, Awesome |
| 2 | MehCars | Mediocrity, YoureSettling |
+-----------+-----------+---------------------------+