I want to create a new table based on this one:
that filters for Warehouse=2 and "drops" the columns "Price" and "Cost" like this:
I have managed to apply the filter in the first step using:
FILTER(oldtable;oldtable[Warehouse]=2)
and then in the next step cold create another table that only selects the required columns using:
newtable2=SELECTCOLUMNS("newtable1";"Articlename";...)
But I want to be able to combine these two functions and create the table straight away.
This is very simple, because in your first step, a table is returned which you can use directly in your second statement.
newTabel = SELECTCOLUMNS(FILTER(warehouse;warehouse[Warehouse]=2);"ArticleName";warehouse[Articlename];"AmountSold";warehouse[AmountSold];"WareHouse";warehouse[Warehouse])
If you want to keep the overview, you can also use variables and return:
newTabel =
var filteredTable = FILTER(warehouse;warehouse[Warehouse]=2)
return SELECTCOLUMNS(filteredTable;"ArticleName";warehouse[Articlename];"AmountSold";warehouse[AmountSold];"WareHouse";warehouse[Warehouse])
Related
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)
In our RethinkDB database, we have a table for orders, and a separate table that stores all the order items. Each entry in the OrderItems table has the orderId of the corresponding order.
I want to write a query that gets all SHIPPED order items (just the items from the OrderItems table ... I don't want the whole order). But whether the order is "shipped" is stored in the Order table.
So, is it possible to write a query that filters the OrderItems table based on the "shipped" value for the corresponding order in the Orders table?
If you're wondering, we're using the JS version of Rethinkdb.
UPDATE:
OK, I figured it out on my own! Here is my solution. I'm not positive that it is the best way (and certainly isn't super efficient), so if anyone else has ideas I'd still love to hear them.
I did it by running a .merge() to create a new field based on the Order table, then did a filter based on that value.
A semi-generalized query with filter from another table for my problem looks like this:
r.table('orderItems')
.merge(function(orderItem){
return {
orderShipped: r.table('orders').get(orderItem('orderId')).pluck('shipped') // I am plucking just the "shipped" value, since I don't want the entire order
}
})
.filter(function(orderItem){
return orderItem('orderShipped')('shipped').gt(0) // Filtering based on that new "shipped" value
})
it will be much easier.
r.table('orderItems').filter(function(orderItem){
return r.table('orders').get(orderItem('orderId'))('shipped').default(0).gt(0)
})
And it should be better to avoid result NULL, add '.default(0)'
It's probably better to create proper index before any finding. Without index, you cannot find document in a table with more than 100,000 element.
Also, filter is limit for only primary index.
A propery way is to using getAll and map
First, create index:
r.table("orderItems").indexCreate("orderId")
r.table("orders").indexCreate("shipStatus", r.row("shipped").default(0).gt(0))
With that index, we can find all of shipper order
r.table("orders").getAll(true, {index: "shipStatus"})
Now, we will use concatMap to transform the order into its equivalent orderItem
r.table("orders")
.getAll(true, {index: "shipStatus"})
.concatMap(function(order) {
return r.table("orderItems").getAll(order("id"), {index: "orderId"}).coerceTo("array")
})
I am using codeigniter and grocerycrud, I want to set a table with grocerycrud in this way:
SELECT * FROM `dashboard`.`medidas_ludlum`
where FK_ludlum='190.26.88.131'
and date>= '2014-03-04 09:40:00'
and date<= '2014-03-05 09:40:00'
and (error_code=1 or audio_status=1);
I tried to do that in this way:
$uno='1';
$crud2 = new grocery_CRUD();
$crud2->set_theme('datatables');
$crud2->where('FK_ludlum',$ludlum_id);
$crud2->where('date>=',$fechainicio);$crud2->where('date<=',$fechafin);
$crud2->where('error_code =',$uno);
$crud2->or_where('audio_status =',$uno);
$crud2->set_table('medidas_ludlum');
$crud2->columns('measurement', 'fecha', 'audio_status', 'high_alarm_status', 'low_alarm_status','over_range_status','monitor_status','error_code');
$crud2->set_language("spanish");
$crud2->unset_add();$crud2->unset_delete();$crud2->unset_edit();$crud2->unset_read();
$data['crud2'] = $crud2->render();
However it's not giving the right results, for example I am getting rows that have a date out of the range, is there a way to get that CRUD set up?
Grocery curd is also using codeigniter's active record so you can write your where() with grouped conditions as below,no need to use or_where() function
$crud2->where('(error_code ='.$uno.' OR audio_status ='.$uno.')',null,FALSE);
or
$crud2->where('(error_code =1 OR audio_status =1)',null,FALSE);
The problem in your query is when you use or_where() function it produces where clause as and error_code=1 or audio_status=1 and using approach that i have provide will give you the where clause as and (error_code=1 or audio_status=1) a grouped condition
API and Functions list
I wonder how I can build a query expression which understands the given item being selected is the first or not. Say I'm selecting 10 items from DB:
var query = db.Table.Take(10).Select(t => IsFirst ? t.Value1 : t.Value2);
There is an indexed variant of Select but that is not supported in LINQ-to-SQL. If it was supported my problems would be solved. Is there any other trick?
I could have used ROW_NUMBER() on T-SQL for instance, which LINQ-to-SQL uses but does not give access to.
I know I can Concat two queries and use the first expression in the first and so forth but I don't want to manipulate the rest of the query, just the select statement itself because the query is built at multiple places and this is where I want to behave differently on first row. I'll consider other options if that is not possible.
You can use the indexed overload, but you need to use the LINQ to Objects version:
var query =
db.Table.Take(10).AsEnumreable()
.Select((t, index) => index == 0 ? t.Value1 : t.Value2);
If Table have a primary key. You could do this:
var result= (
from t in db.Table.Take(10)
let first=db.Table.Take(10).Select (ta =>ta.PrimayKey).First()
select new
{
Value=(t.PrimaryKey=first?t.Value1 : t.Value2)
}
);
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.