I have a MS Access table with lots of records. I want to create a query to randomly select 10% of records. However, the minimum count of records should be 20. So, if the total count of records is 180, it should ignore the 10% criteria and filter out minimum 20 records.
I have successfully retrieved the 10% data using the Top 10% return setup. I need to apply the minimum 20 records criteria. Can someone please guide me further.
You must count the records and adjust the SQL manually:
Const TopCount As String = "20"
Const TopPercent As String = "10%"
Dim Sql As String
Dim TopValue As String
Dim Records As DAO.Recordset
Sql = "Select Top {0} * From YourTable"
If DCount("*", "YourTable") > 200 Then
TopValue = TopPercent
Else
TopValue = TopCount
End If
Sql = Replace(Sql, "{0}", TopValue)
Set Records = CurrentDb.OpenRecordset(Sql)
Related
I've got a controller that first selects all data with status = 'CREATED' transferType = 'SOME_TYPE' and DATE_TIME between x and y, and then put all the data in the List<TransferEntity>
then i am going through each element in the list and updating status to 'CHECKED'
if (listOfTransfers.isNotEmpty()){
for(element in listOfTransfers){
element.status = "CHECKED"
repos.transfers.save(element)
}
}
entity itself is pretty straight forward with no relations to other tables
#Entity
#Table( name = "TRANSFERS")
class TransferEntity(
#Id
#Column(name = "Identifier", nullable = false)
var Identifier: String? = null,
#Column(name = "TRANS_DATE_TIME")
var transDateTime: LocalDateTime? = null,
#Column(name = "TRANS_TYPE", nullable = true, length = 255)
var transType: String? = null,
#Column(name = "STATUS")
var status: String = ""
)
i tried to experiment with indexes (oracle)
`CREATE INDEX TRANS_INDEX_1 ON TRANSFERS(STATUS)`
`CREATE INDEX TRANS_INDEX_2 ON TRANSFERS(TRANS_DATE_TIME)`
`CREATE INDEX TRANS_INDEX_3 ON TRANSFERS(TRANS_TYPE)`
or created them as one index
CREATE INDEX TRANS_INDEX_4 ON TRANSFERS(STATUS,TRANS_DATE_TIME,TRANS_TYPE)
but it wasnt a big difference
UPDATE
witn TRANS_INDEX_1 2 and 3 - 3192 elements were updateind in 5 minutes 30 sec
with TRANS_INDEX_4 - 3192 elements were updated in 5 minutes 30 sec
maybe there are different approaches to mass update elements inside the list or perhaps indexes are completely wrong and i dont understand them as much as i want it to.
UPDATE 2
technically saveAll() method works much faster but still I think there should be a room for improvement
saveAll() - 3192 elements were saved under 3minutes 21seconds
save() 3192 elements were save under 5minutes 30 seconds
You call save() each time you update an element. 1000 elements will create 1000 query calls to the database, you repeat too many calls to your DB and that's why your function is slow.
Instead, you could use saveAll() after you updated all the elements
as suggested below, we also have to config the batch_size properly to really do the trick
Indexes won't help in this situation since they benefit the select operation more than update or insert
Since you set the same value to all the elements of your list, you can make a batch update query :
Query q = entityManager.createQuery("update TransferEntity t set t.status = :value where t in (:list)");
q.setParameter("value", "CHECKED");
q.setParamter("list", listOfTransfers);
q.execute();
If you use ORACLE as backend be aware that in clause is limited to 1000 elements. Therefore you might have to split your list in buckets of 1000 elements and loop on this query for each bucket.
Hi I am trying to add a AVERAGE column in a matrix, but when I put my metric added the average per column, but I need a total AVERAGE and total at the end just once
What I have:
What I need:
Group
Maria
Pedro
average
total
First
4
6
5
10
Second
5
10
7.5
15
Regards
Following the example detailed in the sample data table, to get the Total you could add the following measure;
Total By Group = CALCULATE( SUM(AverageExample[Maria]) + SUM(AverageExample[Pedro]))
and to average
Average By Group = [Total By Group] / 2
Based on the first three columns, this will provide
You have to build a DAX table (or Power Query) and a designated measure.
Matrix Table =
UNION(
DATATABLE("Detail", STRING, "Detail Order", INTEGER, "Type", STRING, {{"Average", 1000, "Agregate"}, {"Total", 1001, "Agregate"}}),
SUMMARIZE('Your Names Table', 'Your Names Table'[Name], 'Your Names Table'[Name Order], "Type", "Names")
)
This should give you a table with the list of people and 2 more lines for the agregations.
After that, you create a measure using variables and a switch function.
Matrix Measure =
var ft = FIRSTNONBLANK('Matrix Table'[Type], 0)
var fd = FIRSTNONBLANK('Matrix Table'[Detail], 0)
return SWITCH(TRUE,
ft = "Names", CALCULATE([Total], KEEPFILTERS('Your Names Table'[Name] = fd)),
fd = "Total", [Your Total Measure],
fd = "Average", [Your Averagex Measure]
)
The rest is up to you to fiddle with orders, add any agregate measures and whatnot.
Note that the Matrix Table should have no relation with any table from your model.
You can also hide it and the Matrix measure.
I have a database table with a datetime column and I simply want to count how many records per day going back 3 months. I am currently using this query:
var minDate = DateTime.Now.AddMonths(-3);
var stats = from t in TestStats
where t.Date > minDate
group t by EntityFunctions.TruncateTime(t.Date) into g
orderby g.Key
select new
{
date = g.Key,
count = g.Count()
};
That works fine, but the problem is that if there are no records for a day then that day is not in the results at all. For example:
3/21/2008 = 5
3/22/2008 = 2
3/24/2008 = 7
In that short example I want to make 3/23/2008 = 0. In the real query all zeros should show between 3 months ago and today.
Fabricating missing data is not straightforward in SQL. I would recommend getting the data that is in SQL, then joining it to an in-memory list of all relevant dates:
var stats = (from t in TestStats
where t.Date > minDate
group t by EntityFunctions.TruncateTime(t.Date) into g
orderby g.Key
select new
{
date = g.Key,
count = g.Count()
}).ToList(); // hydrate so we only query the DB once
var firstDate = stats.Min(s => s.date);
var lastDate = stats.Max(s => s.date);
var allDates = Enumerable.Range(1,(lastDate - firstDate).Days)
.Select(i => firstDate.AddDays(i-1));
stats = (from d in allDates
join s in stats
on d equals s.date into dates
from ds in dates.DefaultIfEmpty()
select new {
date = d,
count = ds == null ? 0 : ds.count
}).ToList();
You could also get a list of dates not in the data and concatenate them.
I agree with #D Stanley's answer but want to throw an additional consideration into the mix. What are you doing with this data? Is it getting processed by the caller? Is it rendered in a UI? Is it getting transferred over a network?
Consider the size of the data. Why do you need to have the gaps filled in? If it is known to be returning over a network for instance, I'd advise against filling in the gaps. All you're doing is increasing the data size. This has to be serialised, transferred, then deserialised.
If you are going to loop the data to render in a UI, then why do you need the gaps? Why not implement the loop from min date to max date (like D Stanley's join) then place a default when no value is found.
If you ARE transferring over a network and you still NEED a single collection, consider applying D Stanley's resolution on the other side of the wire.
Just things to consider...
DB = Oracle 11g
Apex = 4.2.6
In the form I have various items which all work great. However I now have a set of check boxes(:P14_DAYS) one for each day of the week.
What I need to do is get all records between :P14_START_DATE :P14_END_DATE, but only within the days select that's checked.
Below is also a sample of the DATE_SETS table
http://i.stack.imgur.com/YAckN.png
so for example
dates 01-AUG-14 - 5-AUG-14 But only require Sundays AND Mondays date would bring back 2 refs.
BEGIN
UPDATE MD_TS_DETAIL
SET job_for = :P14_JOBFORTEM,
job_type_id = :P14_JOB_TYPE_VALUE,
account_id = :P14_ACC_VAL,
qty = :P14_HRS,
rio = :P14_RIO,
post_code = :P14_POSTCODE
WHERE id IN (SELECT D.id
FROM MD_TS_MAST M
LEFT JOIN MD_TS_DETAIL D
ON M.mast_id = D.md_id
LEFT JOIN DATE_SETS
ON ms_date = dt
WHERE eng_id = :P14_ENG_VAL
AND ms_date BETWEEN :P14_START_DATE AND :P14_END_DATE
AND DATE_SETS.col_day = ANY instr(':'||:P14_DAYS||':',Return)
END;
Any help would be much appreciated .
I found this example: http://docs.oracle.com/cd/B31036_01/doc/appdev.22/b28839/check_box.htm#CHDBGDJH
As I can understand, when you choose some values in your checkbox list, item :P14_DAYS receives value, that contains return values of chosen elements of the LOV with delimiters. Then you need to replace this string in your query
AND DATE_SETS.col_day = ANY instr(':'||:P14_DAYS||':',Return)
with
AND instr(':'||:P14_DAYS||':', ':'||DATE_SETS.col_day||':') > 0
Here function instr searches substring DATE_SETS.col_day in string :P14_DAYS. It returns position of substring if substring was found or 0, if not found. Then you compare result of function with 0, and if result > 0, it means that DATE_SETS.col_day is among selected values.
I search lot but not getting any help on random records with mysql.I am using random query to get random data from database with not in with some limit. If database contains 100 records and suppose I am giving 30 as limit with random function and some not in id.My problem is that when it hit first time I am giving not in id as empty and it is giving me 30 records randomly.But for second time except last 30 records i.e(it is in not in variable) it should give me another 30 records from 70 records but it is giving me less than 30 i.e(28,29).This because first it applies random function and limit and then filter it with not in.My query is like below:
$subQuery = $this->select()
->from(array('s' => 'shop'), array('s.shop_id','b.shop_name','b.shop_template_id'))
->order('RAND()')
->where('s.shop_id NOT in (?)', $shop_id)
->limit(30);
$query = $this->select()
->from(array('b' => $subQuery), array('*'))
->join(array('p' => 'product'), 's.shop_id = p.shop_id', array('p.product_price'))
->setIntegrityCheck(false);
$resultRows = $this->fetchAll($query);
Update: I got the problem why it is giving (28,29) records sometime because join query contains product for shop and if some shop is having 0 products it does not get that shop.My question is that irrespective of product how can i get that shop from database.
Your problem is that you join instead of left join. Also there's no need for a sub select. This should work:
$objSelect = $this->select()->setIntegrityCheck(false);
$objSelect->from(
array('s' => 'shop'),
array('s.shop_id','b.shop_name','b.shop_template_id')
);
$objSelect->joinLeft(
array('p' => 'product'),
's.shop_id = p.shop_id',
array('p.product_price')
);
$objSelect->order('RAND()');
$objSelect->limit(30);
$objRowSet = $this->fetchAll($objSelect);