I have 3 entities.
VehicleType has a many vehicles and each vehicle has a many rents. Each rent has TotalKm.
I want to know the sum of TotalKm for all rents for each vehicle type.
I try this:
public async Task<IEnumerable<VehicleTypeDto>> GetAllAsync()
{
return await _unitOfWork.
VehicleTypesRepository.
GetEntityAsNoTracking().
Include(entity => entity.Vehicles).ThenInclude(entity => entity.Rents).ThenInclude(entity => entity.Damages).
Select(entity => new VehicleTypeDto
{
Id = entity.Id,
Code = entity.Code,
Description = entity.Description,
TotalKm = entity.Vehicles.Sum(v => v.Rents.Sum(r => r.TotalKm )) ?? 0,
}).
OrderBy(entity => entity.Description).
ToListAsync();
}
But I have this error:
Cannot perform an aggregate function on an expression containing an
aggregate or a subquery.
Someone can help me pls?
Related
At this moment I do query like this :
static async getAllAppointmentSerivce () {
// Get all appointment with detail
const query = {
name: 'getAllAppointment',
text: 'SELECT app.id, cus.name as name, cus.email as email, app.date, app.status, app.link FROM appointments app INNER JOIN admins adm ON app.admin_id = adm.id INNER JOIN customers cus ON app.customer_id = cus.id ORDER BY id ASC'
}
return pool.query(query)
.then(async res => {
for (let i = 0; i < res.rows.length; i++) {
const admin = await AdminService.getAdminDetailByAppointmentId(res.rows[i].id)
res.rows[i].admin = admin
}
return res.rows
})
.catch(err => console.log(err.stack))
}
And the result is like this :
Query result
My question is, is that possible to do that in a single query?
I have the following tables:
users:
------
id
first_name
current_property_id
property_users:
---------------
id
user_id
property_id
chat_user_id
nickname
chat_users:
-----------
id
identity
chat_groups:
------------
id
name
type ['Single' means the group a user is having permutation without repetition for all property users that will serve as their 1:1 conversation (in short everyone is paired with everyone once), 'Group' means more than 2 people can be in the group]
last_messaged_at
chat_group_members:
-------------------
id
chat_group_id
user_id
chat_user_id
I need to make a query to fetch all users (except me) in the property I am in and get the chat_groups I have with them (Type == Single).
I tried doing it PHP way but it takes too long (for 125 users it takes +30s of response)
This is how I am doing it in PHP
$this->currentUser = auth()->user();
//this is Fluent using DB::table and joining property_users, chat_users, and users
$propertyUsers = $this->run(GetPropertyUsersJob::class, [
'property' => $this->property
]);
//this is using simple eloquent getting groups
$chatGroups = $this->run(GetGroupsJob::class, [
'property' => $this->property,
'type' => ChatGroup::TYPE_SINGLE
]);
$chatGroups->load('members.user');
//first level of loop
foreach($propertyUsers as $propertyUser) {
if($this->currentUser->id == $propertyUser->user_id) {
return [];
}
$chatGroupId = '';
$chatGroupName = '';
//second level of loop
foreach($chatGroups as $chatGroup) {
$found = 0;
//third level of loop
foreach($chatGroup->members as $member) {
if($member->user_id == $this->currentUser->id) {
$found++;
}
if($member->user_id == $propertyUser->user_id) {
$found++;
}
}
//just to get this, I need to do nested loop 3x
if($found == 2) {
$chatGroupId = $chatGroup->id;
$chatGroupName = $chatGroup->name;
}
}
$user[] = [
'id' => $propertyUser->user_id,
'first_name' => $propertyUser->user->first_name,
'nickname' => $propertyUser->nickname,
'chat_group_id' => $chatGroupId,
'chat_group_name' => $chatGroupName
];
}
How can I convert this to a query (eloquent/fluent) instead?
#Update:
User model: I am only adding related eager loading
-----------
public function property_users()
{
return $this->hasMany(PropertyUser::class, 'user_id', 'id');
}
PropertyUser model:
-------------------
public function user()
{
return $this->belongsTo(User::class);
}
public function chat_user()
{
return $this->hasOne(ChatUser::class, 'id', 'chat_user_id');
}
ChaUser model:
--------------
public function property_user()
{
return $this->belongsTo(PropertyUser::class, 'id', 'chat_user_id');
}
I use react native through firebase database
I have a database creating products each product has a number
I want to take a number and compare it with the product number
And if there is then I want to get a product
the function its give me my correct name but where i use it on render its not found the variable (name)
getAllContact = async key => {
let barCodeData2 = this.props.navigation.state.params.barcodeData
let self = this;
let contactRef = firebase.database().ref()
contactRef.on("value", dataSnapsot => {
if (dataSnapsot.val()) {
let contactResult = Object.values(dataSnapsot.val())
let contactKey = Object.keys(dataSnapsot.val())
contactKey.forEach((value, key) => {
contactResult[key]["key"] = value
})
self.setState({
fname: contactResult.fname,
data: contactResult.sort((a, b) => {
var nameA = a.barcode
var nameB = barCodeData2
const name = a.fname
console.log(`${nameA} What numers issssssss`);
if (nameA == nameB) {
alert(`${name} ........`)
console.log(`${nameA == nameB}is Equqlqlqlql`);
return name
}
}),
})
}
})
}
render() {
let t=this.state.name
alert(`${t} how?`)// is give Not found
// let d = this.props.navigation.state.params.barcodeData
return (
)
}
When you try such a comparison query i.e.
let ref = firebase.firestore();
ref.collection('zoo')
.where("id", "==", myID)
.get()
.then((snapshot) => {
console.log(snap.empty); //this will denote if results are empty
snapshot.forEach(snap => {
console.log(snap.exists); //alternatively this will also tell you if it is empty
})
})
well what you can do is run query based on you product no and if there's a product you will a product if there's none you will get an empty array.
read firebase documentation on queries
https://firebase.google.com/docs/reference/js/firebase.database.Query
I'm attempting to translate some T-SQL to an Entity Framework Core lambda expression. It involves an inner join and a left joing with a where clause.
Here is the working SQL query:
SELECT
AspNetUsers.*, Exclusions.*
FROM
AspNetUsers
JOIN Exclusions ON
AspNetUsers.FirstName = Exclusions.FirstName
AND AspNetUsers.LastName = Exclusions.LastName
LEFT JOIN ExclusionsMatches ON
ExclusionsMatches.RowHash = Exclusions.RowHash
WHERE
ExclusionsMatches.MatchIgnoredByUserId IS NULL
Which I have thus far translated into LINQ lambda as such:
var result = _db.Users
.Join(_db.Exclusions, usr => new { usr.FirstName, usr.LastName }, Exc => new { Exc.FirstName, Exc.LastName }, (usr, Exc) => new { usr, Exc })
.GroupJoin(_db.ExclusionsMatches, i => i.Exc.RowHash, x => x.RowHash, (i, ExcMatch) => new { User = i.usr, Exc = i.Exc, ExcMatch = ExcMatch })
.SelectMany(temp => temp.ExcMatch.DefaultIfEmpty(), (temp, p) => new { User = temp.User, Exc = temp.Exc, ExcMatch = temp.ExcMatch})
This seems to give me the desired query output, but I can't seem to figure out how to get the WHERE ExclusionsMatches.MatchIgnoredByUserId IS NULL clause translated.
Any thoughts on how the WHERE might be achieved? I'm also open to changing from lambda expression to linq query expression.
Thanks!
I believe using LINQ is more readable so I can provide an answer using LINQ as below.
from user in _db.Users
join excl in _db.Exclusions on new { usr.FirstName , usr.LastName} equals {excl.FirstName , excl.LastName}
join exclMtch in _db.ExclusionsMatches on excl.RowHash equals exclMtch.RowHash into grp
from itm in grp.DefaultIfEmpty()
where itm.MatchIgnoredByUserId == null
select new {
user,
excl
}
Otherwise, if you insist on using Lambda, first you have to select the field in your final selects and then add the needed where in the end of query.
var result = _db.Users
.Join(_db.Exclusions, usr => new { usr.FirstName, usr.LastName }, Exc => new { Exc.FirstName, Exc.LastName }, (usr, Exc) => new { usr, Exc })
.GroupJoin(_db.ExclusionsMatches, i => i.Exc.RowHash, x => x.RowHash, (i, ExcMatch) => new { User = i.usr, Exc = i.Exc, ExcMatch = ExcMatch MatchIgnoredByUserId = i.MatchIgnoredByUserId })
.SelectMany(temp => temp.ExcMatch.DefaultIfEmpty(), (temp, p) => new { User = temp.User, Exc = temp.Exc, ExcMatch = temp.ExcMatch, MatchIgnoredByUserId= temp.MatchIgnoredByUserId })
.Where(q => q.MatchIgnoredByUserId == null )
Do not forget to track your query in SQL Profiler :)
How can i convert this in LINQ?
SELECT B.SENDER, B.SENDNUMBER, B.SMSTIME, B.SMSTEXT
FROM MESSAGES B
WHERE EXISTS ( SELECT A.SENDER
FROM MESSAGES A
WHERE A.SENDER = B.SENDER
GROUP BY A.SENDER
HAVING B.SMSTIME = MAX( A.SMSTIME))
GROUP BY B.SENDER, B.SENDNUMBER, B.SMSTIME, B.SMSTEXT ;
Thanks a lot :)
EDIT!!
Resolved with:
var Condition = "order by SMSTime desc";
IEnumerable<ClassMessaggio> messaggi = Database.Select<ClassMessaggio>(Condition);; // Load all but sorted
ElencoConversazioni = messaggi.GroupBy(m => new { m.Number })
.Select(g => g.OrderByDescending(m => m.SMSTime).First()).ToObservableCollection();
Try
db.Messages.Where(b => b.SmsTime == Messages.Where(a => a.Sender == b.Sender)
.Max(a => a.SmsTime))
Or
db.Messsages.GroupBy(m => new { m.Sender, m.SendNumber })
.Select(g => g.OrderByDescending(m => m.SmsTime).First())
Where db is your DataContext.
To show the list of conversations along with "the last message of every contact", you could try something like:
// a query to find the last Sms time per sender
var lastSmsQuery = from m in db.messages
group m by m.Sender into grouping
select new
{
Sender = grouping.Key,
LastSmsTime = grouping.Max(x => x.SmsTime)
};
// a query to find the messages linked to the last Sms per sender
var lastMessageQuery = from m in db.messages
join l in lastSmsQuery on new { m.Sender, m.SmsTime } equals new { l.Sender, l.LastSmsTime }
select m;
The 2-query method used is similar to that of this question from earlier today - Convert SQL Sub Query to In to Linq Lambda