Is there any way to limit the number of records returned from a query using CloudKit framework? E.g. only return the latest value by sorting it by date (already figured that out) but then limit the returned records to 1?
Yes, use a CKQueryOperation and it's resultsLimit property.
resultsLimit
The maximum number of records to return at one time.
Discussion
For most queries, leave the value of this property as the
default value, which is the maximumResults constant. When using that
value, CloudKit returns as many records as possible while minimizing
delays in receiving those records. If you want to process a fixed
number of results, change the value of this property accordingly.
Related
I want the no of records available in the database for the current query but without considering the LIMIT.
$this->Orders->find('all')
->where(['order_quantity']=>5)
->LIMIT(5);
Let's consider, I have 50 no of records for this above query. So just want the no of records available for the current query. I can't use 'count()' because of the limit it will always return total no of records available is less than or equal to 5. Is there any solution in cakePHP.
This page in the CakePHP 3 book, explains EXACTLY the answer to your question including how and why it works:
Returning the Total Count of Records
Using a single query object, it is possible to obtain the total number
of rows found for a set of conditions:
$total = $articles->find()->where(['is_active' => true])->count();
The count() method will ignore the limit, offset and page clauses,
thus the following will return the same result:
$total = $articles->find()->where(['is_active' => true])->limit(10)->count();
This is useful when you need to know the total result set size in
advance, without having to construct another Query object. Likewise,
all result formatting and map-reduce routines are ignored when using
the count() method.
Notice the bit about "... will ignore the limit, offset, and page clauses"
So try something like this:
$data = $articles->find()->where(['is_active' => true])->limit(10);
$count = $data->count();
I don't think you are familiar with the use of limit in find. So, I suggest you to study the docs.
The limit in your query means that the query will only display first 5 data even if the query actually has 50 data.
So, in order to get the actual data, you just need to remove the limit and make some changes in your code as follows:
$this->Orders->find('count')->where(['order_quantity' => 5]);
Given the following code:
var dbRecords = _context.Alerts.AsNoTracking()
.Where(a => a.OrganizationId == _authorization.OrganizationId)
.ToList();
var dbRecords2 = _context.Alerts
.Where(a => a.OrganizationId == _authorization.OrganizationId)
.ToList();
foreach (var untrackedRecord in dbRecords) {
var trackedRecord = dbRecords2.First(a => a.Id == untrackedRecord.Id);
Assert.AreEqual(untrackedRecord.TimeStamp.Ticks, trackedRecord.TimeStamp.Ticks);
}
Where the TimeStamp data is stored in SQL Server 2012 in a column defined as datetime2(0).
The Assert fails, and the debugger demonstrates that the two Ticks values are always different.
Expected: 636179928520000000 But was: 636179928523681935
The untracked value will always be rounded off to the nearest second (which is expected, based on what SQL is storing). When creating the record, the value I'm saving comes from DateTime.Now.
Testing some more, this doesn't appear to be true (the inconsistent ticks) for every object I'm testing, only for records I've inserted recently. Looking at the code and given the way the column is defined, it's not obvious to my why that would matter.
For now, to get my tests to pass, I'm just comparing the DateTime values down to the second, which is all that's required. However, I'm just wanting to understand why this is happening: Why can I not reliably compare two DateTime values depending on whether or not the entities are being tracked?
I figured this out, so answering my own question; I found I left off what turns out to be a key piece of information here. I mentioned that this issue came up in testing. What I didn't mention is that we're inserting the records and then testing all within a single transaction, and within a single DbContext.
Because I use the same DbContext for all work, the Alert objects that are inserted for testing are cached. When I query the objects using AsNoTracking, the DbContext has to refresh the objects before giving them back to me (since their current state isn't being tracked, and therefore is unknown to EF), apparently without updating what's in the cache (since we told EF we don't want to track the objects).
Querying for the same objects without AsNoTracking results in a cache hit; those objects that were inserted are still in the cache, so the cached versions are returned.
Given that, it's clear why the Ticks aren't matching up. The non-cached objects are pulling the DateTime values from the database, where the precision is defined to only store the time down the nearest second. The cached objects have the original DateTime.Now values, which stores the time down to ms. This explains why the Ticks don't match between the two DateTimes, even though both objects represent the same underlying database record.
Apparently the default query limit on the number of returned documents is currently 20. Changing it is possible by using QueryOptions.Builder.setLimit(). Java dev docs don't seem to indicate the allowed maximum.
I have thousands of records indexed in my application and searches might potentially return a large number of objects. Instead of hardcoding something like MAX_QUERY_RESULTS = 1000 in the app, is there a way to programmatically access this search quota?
The class com.google.appengine.api.search.checkers.SearchApiLimits has a long list of constants of this ilk, including SEARCH_MAXIMUM_LIMIT with the value 1000.
Using the PHP library for salesforce I am running:
SELECT ... FROM Account LIMIT 100
But the LIMIT is always capped at 25 records. I am selecting many fields (60 fields). Is this a concrete limit?
The skeleton code:
$client = new SforceEnterpriseClient();
$client->createConnection("EnterpriseSandboxWSDL.xml");
$client->login(USERNAME, PASSWORD.SECURITY_TOKEN);
$query = "SELECT ... FROM Account LIMIT 100";
$response = $client->query($query);
foreach ($response->records as $record) {
// ... there's only 25 records
}
Here is my check list
1) Make sure you have more than 25 records
2) after your first loop do queryMore to check if there are more records
3) make sure batchSize is not set to 25
I don't use PHP library for Salesforce. But I can assume that before doing
SELECT ... FROM Account LIMIT 100
some more select queries have been performed. If you don't code them that maybe PHP library does it for you ;-)
The Salesforce soap API query method will only return a finite number of rows. There are a couple of reasons why it may be returning less than your defined limit.
The QueryOptions header batchSize has been set to 25. If this is the case, you could try adjusting it. If it hasn't been explicitly set, you could try setting it to a larger value.
When the SOQL statement selects a number of large fields (such as two or more custom fields of type long text) then Salesforce may return fewer records than defined in the batchSize. The reduction in batch size also occurs when dealing with base64 encoded fields, such as the Attachment.Body. If this is the case they you can just use queryMore with the QueryLocator from the first response.
In both cases, check the done and size properties of the done and size properties of the QueryResult to determine if you need to use queryMore and the total number of rows that match the SOQL query.
To avoid governor limits it might be better to add all the records to a list then do everything you need to do to the records in the list. After you done just update your database using: update listName;
I want to retrieve the last row from the data store so how can i do that??
I know the long method i.e
for(Table_name e: resultset)
{
cnt++;
}
results.get(cnt).getvalue();
I have String with (number) as primary key.can i use it to get descending order???
Is there any method through which i can get the last row???
You should probably sort in the opposite order (if possible for your query, the data store has some restrictions here) and get the first result of that.
Also, if you store numbers in String fields the order may not be what you want it to be (you might need padding here).