I have 2 queries, I want to know which is the best query
Model::select('id')->where('status','1')->first();
Model::lists('id')->where('status','1')->first();
Please let me know
The first one is better because it gets only one object. But a better way to get ID of the first row with status = 1 is to use the value() method:
Model::where('status', '1')->value('id');
The second query is bad because it loads all IDs into memory and then filters them.
Related
I'm used to compare 2 data, one data has an id and the other data is the one that needs comparing to get the matching datas. see code below.
DB::table('requests')->where('reqItem',$inventory->invItem)->get();
The code shown above displays all requests information that equals to the compared inventory item.
Now what i want to do now is to compare 2 tables without any id (ex. $inventory->invItem). I don't know how to ask this question but i hope you get what i mean. The figure below shows the way i wanted it to be.
You can run this query. Here, 'inventory' is the name of second table (change it accordingly)
DB::table('requests')
->join('inventory', 'requests.reqItem', '=', 'inventory.invItem')
->select('inventory.reqItem')
->get();
I'm trying to send API with certain number of records
$category->products
I tried to use limit() or take() but it fails
so is there any smart solution than go to pivot and select it with limit ??
Copy data to a new collection.
$collection =$category->products;
you can now send the number of times you want using take ().
for example;
$collection->take(5);
if your question is different please explain it more clearly.
I found the solution I was easy
$category->products()->limit(2)->get()->all()
that's all
I am kind of annoyed at Doctrine for returning primary keys in each and every query even though I don't want it to. Is there anyway to stop this ? coz I don't really want those damn primary keys along with my doctrine query results.
A query for instance that I have is:
$getAllDatesForUserQuery = $this->createQuery('s')
->select('s.datename')
->where('s.userid = ?',3)
->setHydrationMode(Doctrine::HYDRATE_ARRAY) ;
In this situation, it retrieves all the datenames as it should, but also happily returns the primary key column value. I DON"T WANT IT.
Is it me? or is it Doctrine ?
In a case like this where you want a simple array and only have a single field being selected, the answer is the Single Scalar Hydration mode. Use it like this:
$q = $this->createQuery('s')
->select('s.datename')
->where('s.userid = ?',3)
->setHydrationMode(Doctrine::HYDRATE_SINGLE_SCALAR);
You should find that the query will return a simple one-dimensional array containing only the value(s) you wanted.
im trying to run an hql query which aggragets (sum) number of transactions made on a specific account, i dont need a group by since my where clause has a specific account filter (where account = :account)
i do, however, want to return the aggregated value only if it is smaller/bigger than some given value.
when im adding 'having' after the where clause without 'group by' im getting an error -
unexpected token: having
in native sql i succeeded adding 'having' without group by
any ideas on how to make it work with hql?
thanks alot
The reason why databases don't let you mix grouped columns with non-grouped and non-aggregated ones is, that for non-grouped/non-aggregated columns it would have to choose one row's value per group, but doesn't know how to pick one.
If you don't care, then you could just leave it away and if it doesn't matter because they're all the same, you could group by them, too.
It is not hql, but if you have native query, then run it like:
Query query = session.createSQLQuery("select, *** ,... blah blah")
//set If you need
query.setParameter("myparam", "val");
List result = query.list();
In my eyes this is nonsense. 'having' is done for conditions on a 'group by' result. If you don't group, then it does not make much sense.
I would say HQL can't do it. Probably the Hibernate programmers didn't think of this case because they considered it as not important.
And anyway, you don't need it.
If it is a simple query, then you can decide in your java code if you want the result or if you don't need it.
If it is in a subselect, then you can solve the problem with a where condition in the main select.
If you think it is really necessary then your invited to give a more concrete example.
I am trying to solve a problem of deleting only rows matching two criteria, each being a list of ids. Now these Ids are in pairs, if the item to be deleted has one, it must have the second one in the pair, so just using two in clauses will not work. I have come up with two solutions.
1) Use the two in clauses but then loop over the items and check that the two ids in question appear in the correct pairing.
I.E.
for(Object__c obj : [SELECT Id FROM Object__c WHERE Relation1__c in :idlist1 AND Relation2__c in:idlist2]){
if(preConstructedPairingsAsString.contains(''+obj.Relation1__c+obj.Relation2__c)){
listToDelete.add(obj);
}
}
2) Loop over the ids and build an admittedly long query.
I like the second choice because I only get the items I need and can just throw the list into delete but I know that salesforce has hangups with SOQL queries. Is there a penalty to the second option? Is it better to build and query off a long string or to get more objects than necessary and filter?
In general you want to put as much logic as you can into soql queries because that won't use any script statements and they execute faster than your code. However, there is a 10k character limit on soql queries (can be raised to 20k) so based on my back of the envelope calculations you'd only be able to put in 250 id pairs or so before hitting that limit.
I would go with option 1 or if you really care about efficiency you can create a formula field on the object that pairs the ids and filter on that.
formula: relation1__c + '-' + relation2__c
for(list<Object__c> objs : [SELECT Id FROM Object__c WHERE formula__c in :idpairs]){
delete objs;
}