Write query which run on array by considring sub query in Parse - parse-platform

I need to write a query in such way that the array(collection) is contain only sub query objects.
Suppose we have the two tables as follows:
TableA:
objectId, name
TableB:
objectId, names[array of name: parse pointer collection]
Here is my code which I tried:
// sub query
var subQuery = new Parse.Query('TableA');
subQuery.doesNotExist('name');
// main query
var query = new Parse.Query('TableB');
query.exists("names");
//query.containsAll("names", subQuery); // this means names should contain all subQuery, so this is not use full for me.
query.matchesQuery("names", subQuery);
This code is running fine, but this is not working as I want and also not showing the any error.

It seems that you don't need a subquery per se, but rather to first query your list of names, and then use that in your main query. What you seem to be looking for is: containedIn( key, values ) , as in:
query.containedIn("name", namesFromFirstQuery)

Related

For table cmdb_rel_ci, I want to retrieve unique parent.sys_class_name with count for "type=In Rack::Rack contains"

For table cmdb_rel_ci, I want to retrieve unique parent.sys_class_name with count for "type=In Rack::Rack contains". I am doing practice in out of the box instance.
At table level URL is as below:
URL
I want to retrieve result from above URL with my below script.
var count = new GlideAggregate('cmdb_rel_ci');
count.addQuery('type','e76b8c7b0a0a0aa70082c9f7c2f9dc64');// sys_id of type In Rack::Rack contains e76b8c7b0a0a0aa70082c9f7c2f9dc64
count.addAggregate('COUNT', 'parent.sys_class_name');
count.query();
while(count.next()){
var parentClassName = count.parent.sys_class_name.toString();
var parentClassNameCount = count.getAggregate('COUNT','parent.sys_class_name');
gs.log(parentClassName + " : " + parentClassNameCount );
}
The issue is I am getting parentClassName empty.
Try this instead:
var parentClassName = count.getValue("parent.sys_class_name")
Since it's a GlideAggregate query (instead of GlideRecord), the query being issued isn't returning all of the fields on the target table. With GlideRecord, dot-walking through a reference field (e.g. parent.sys_class_name) automatically resolves that referenced record to provide access to its field values. This is made possible by the fact that the driving/original query brought back the value of the parent field. This is not happening with GlideAggregate. The query in this case basically looks like:
SELECT cmdb1.`sys_class_name` AS `parent_sys_class_name`, count(*)
FROM (cmdb_rel_ci cmdb_rel_ci0 LEFT JOIN cmdb cmdb1 ON cmdb_rel_ci0.`parent` = cmdb1.`sys_id` )
WHERE cmdb_rel_ci0.`type` = 'e76b8c7b0a0a0aa70082c9f7c2f9dc64'
GROUP BY cmdb1.`sys_class_name`
ORDER BY cmdb1.`sys_class_name`
So, you actually have access specifically to that dot-walked sys_class_name that's being grouped, but not through the dot-walk. The call to getValue("parent.sys_class_name") is expectedly resolved to the returned column aliased as parent_sys_class_name.
That being said, what you're doing probably should also work, based on user expectations, so you've not done anything incorrect here.

Laravel query builder - Select elements unique or null on specific column

I have a model Form for table forms. There is a column called guid which can be null, or contain some sort of grouping random hash.
I need to select all forms that have column guid either null or unique in current search. In other words, for repeating guid values in current search I select only first occurence of every guid hash.
I tried:
$results = App\Form::where(... some where clauses .. ).groupBy('guid')
and it's almost ok, but for all rows, where guid == NULL it groups them and selects only one (and I need all of them).
How can I get the unique or null rows either by building proper SQL query or filtering the results in PHP?
Note: I need my $results to be an Illuminate\Database\Eloquent\Builder instance
EDIT:
I fount out that SQL version of query I need is:
SELECT * FROM `forms` WHERE .... GROUP BY IFNULL(guid, id)
What would be equivallent query for Laravel's database query builder?
UPDATE: Using DB::raw
App\Form::where(... conditions ...)
->groupBy(DB::raw("IFNULL('guid', 'id')"));
Or the another way could be:
You can also use whereNotNull, whereNull & at last merge both the collections using merge() like this:
First get the results where guid is grouped by (excluding null guid's here):
$unique_guid_without_null = App\Form::whereNotNull('guid')->groupBy('guid')->get();
Now, get the results where guid is null:
$all_guid_with_null = App\Form::whereNull('guid')->get();
and at last merge both the collections using merge() method:
$filtered_collection = $unique_guid_without_null->merge($all_guid_with_null);
Hope this helps!
For your edited question, you can use raw() as;
->groupBy(DB::raw("IFNULL('guid', 'id')"))
So your final query will be as:
$results = App\Form::where(... some where clauses .. )
->groupBy(DB::raw("IFNULL('guid', 'id')"));
By above query, your $results will be an instance of Illuminate\Database\Eloquent\Builder.

.Where in LinQ not working correctly

I have Documents table and Signs table. Document record can be related with many records in Signs table.
Now, I want to get all records of Documents table when document ID appears in Signs table.
Here I get all documents:
var documents = (from c in context.documents select c);
Here I get all my signs and save into List:
var myDocuments = (from s in context.signs where s.UserId== id select s.ID).ToList();
This list contains collection on document ID.
And here, I'm trying to get all documents that exists in myDocuments list:
documents.Where(item => myDocuments.Contains(item.ID));
But, when I do .ToList() allways return all records (in database only exists one compatible record)
What is wrong in LinQ statement?
The problem is that this statement doesn't modify the contents of documents, it merely returns the results (which you're not doing anything with):
documents.Where(item => myDocuments.Contains(item.ID));
documents is still the full list.
Change this line to something like:
var matchingIDDocs = documents.Where(item => myDocuments.Contains(item.ID));
And then use matchingIDDocs in place of "documents" later in your code.

How to query a field in a related object in a ParseQuery

I'm using Parse.com and I am running a query that obtains objects in a many-to-many relational table (call this table 'RelationTable'). Obviously this table has links to objects in another table (let's call this SubObject). Now, from this query, I need to filter results by searching on a field contained within the SubObject (call this SearchField).
Any ideas on how to do this? I already have the includeKey and am trying the '.' operator in SQL to access a field in the subclass, but it's not working. Below is the code I have so far:
ParseQuery<ParseObject> query = ParseQuery.getQuery("RelationTable);
query.include("subObject"); //subObject is field name where SubObject is stored. Note CAPS difference
query.whereContains("SubObject.SearchField", searchString);
You can create a subquery on the user object, and use whereMatchesQuery on your RelationTable query :
ParseQuery<ParseObject> query = ParseQuery.getQuery("RelationTable);
query.include("subObject");
ParseQuery<ParseObject> innerQuery = ParseQuery.getQuery("SubObject");
innerQuery.whereContains("SearchField", searchString);
query.whereMatchesQuery("subObject", innerQuery);

Linq Contains issue: cannot formulate the equivalent of 'WHERE IN' query

In the table ReservationWorkerPeriods there are records of all workers that are planned to work on a given period on any possible machine.
The additional table WorkerOnMachineOnConstructionSite contains columns workerId, MachineId and ConstructionSiteId.
From the table ReservationWorkerPeriods I would like to retrieve just workers who work on selected machine.
In order to retrieve just relevant records from WorkerOnMachineOnConstructionSite table I have written the following code:
var relevantWorkerOnMachineOnConstructionSite = (from cswm in currentConstructionSiteSchedule.ContrustionSiteWorkerOnMachine
where cswm.MachineId == machineId
select cswm).ToList();
workerOnMachineOnConstructionSite = relevantWorkerOnMachineOnConstructionSite as List<ContrustionSiteWorkerOnMachine>;
These records are also used in the application so I don't want to bypass the above code even if is possible to directly retrieve just workerPeriods for workers who work on selected machine. Anyway I haven't figured out how it is possible to retrieve the relevant workerPeriods once we know which userIDs are relevant.
I have tried the following code:
var userIDs = from w in workerOnMachineOnConstructionSite select new {w.WorkerId};
List<ReservationWorkerPeriods> workerPeriods = currentConstructionSiteSchedule.ReservationWorkerPeriods.ToList();
allocatedWorkers = workerPeriods.Where(wp => userIDs.Contains(wp.WorkerId));
but it seems to be incorrect and don't know how to fix it. Does anyone know what is the problem and how it is possible to retrieve just records which contain userIDs from the list?
Currently, you are constructing an anonymous object on the fly, with one property. You'll want to grab the id directly with (note the missing curly braces):
var userIDs = from w in workerOnMachineOnConstructionSite select w.WorkerId;
Also, in such cases, don't call ToList on it - the variable userIDs just contains the query, not the result. If you use that variable in a further query, the provider can translate it to a single sql query.

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