I have the following table structure :
Artists
id
name
picture
Entry
id
dj_id
producer_id
dj_id and producer_id field in most cases won't be the same, but it might happen. So I've set both field to be foreign keys on the artists_id field.
So in my Entry model, I have this function :
public function dj()
{
return $this->hasOne('Artist', 'id', 'dj_id');
}
This doesn't really work. It keeps returning the artist with id "1" even if the dj_id equals "5". Code sample :
$test = Entry::find(1);
var_dump($test->dj_id); // shows 5
var_dump($test->dj->id); // shows 1
What am I doing wrong ?
Ok so I figured it out, I had to change my dj relation to
return $this->belongsTo('Artist', 'dj_id', 'id');
Related
In Laravel trying to query a table for invoices (table name: invoices) where the invoice total (field name: net_total) is greater than the sum of payments made for that invoice. It is set as a polymorphic relationship.
Invoice Table:
public function transactions(){
return $this->morphMany(TransactionAllocation::class, 'doc');
}
Payment Table:
public function doc()
{
return $this->morphTo();
}
I tried the query which does not seem to work.
Invoice::with('transactions')
->where('net_total', '>' ,'transactions.amount')
->get();
I tried the following as per an answer below which gives me sum of relationship but the where condition fails
Invoice::withSum('transactions', 'amount')
->where('net_total','>','transactions_sum_amount')
->get();
Screenshot of result - https://prnt.sc/1favj7u
The second array shouldn't have comes as it fails where condition.
Any advice on what am I missing?
Since you will have many transactions as you said, that is the part missing in the query.
You can try something with withSum for example
InvoiceTest::withSum('transactions', 'amount')
->havingRaw('transactions_sum_amount < invoices.net_total')
->get();
I have a database table that looks like this:
My goal is to update my "unavail" table based on the ID of either the component, part, or item depending on which one is relevant in my situation.
For example, if the partID = 43 I want to add to the 'unavail' column
I first started working on this by trying this
db.OffSiteItemDetails.Find(sod.PartID).unavail += sod.comp_returned;
(Where sod.PartId = 43)
But I quickly realized it was just checking for where the "ID" was equal to 43 which isn't what I want. After some investigation I saw people suggesting using
db.Where(x => x.non-pk == value)
So I created this
db.OffSiteItemDetails.Where(x => x.componentID == sod.ComponentID);
But from here I don't know how to change my unavail table values.
This was a tough question to type so if you need more clarity just ask
foreach(var item in db.OffSiteItemDetails.Where(x => x.componentID == sod.ComponentID))
{
// item.unavail = [new value]
// db.Update(item);
// ...I don't know how you update the data in your database
}
Something like that?
I have three tables - Chairman, Designation, Members.
MY requirement is to map the member to chairman and assign member a role.
I was able to fetch the list of members under the chairman when I had chairman_id and designation_id in the members table.
Since the chairman change, most of the members stay intact. So I came up with an idea of indexing them
Table - membermap
id | chairman_id | designation_id | member_id
So the list is preserved how many chairmans come and go. I dont need to create new profile for new chairman rather than map to it.
I am now sure how do I do it,
So far I was able to pull the ID but I am not sure how do I join the tables
Tables
Chairman
id| name
Designation
id|designation
Members
id|members
Here is my controller
$mapmember = Statechairman::findOrFail($id)->statechairmembersmap;
dd($mapmember);
In this Iam getting the statechairmembersmap but it's fetching all the result and not limiting the match.
I also tried to join the query using the DB
$mapmember = DB::table('statechairmen')
->join('state_chairman_members_maps', 'state_chairman_members_maps.chairman_id','statechairmen.id')
->join('statemembers','statemembers.id','state_chairman_members_maps.members_id')
->select('state_chairman_members_maps.*')->get();
but this result show me the Table - membermap but not the other results.
My Models:
Chairman :
public function statechairmembersmap(){
return $this->hasMany('App\StateChairmanMembersMap','chairman_id','id');
}
public function statemembers(){
return $this->hasMany('App\Statemembers','chairman_id', 'id');
}
public function statedesignation(){
return $this->hasMany('App\Statedesignation','id','designation_id');
}
membermap:
protected $table = 'state_chairman_members_maps';
protected $dates = ['deleted_at'];
public function statechairman(){
return $this->belongsTo('App\Statechairman','id');
}
public function statedesignations(){
return $this->belongsTo('App\Statedesignation','designation_id','id');
}
public function statemembers(){
return $this->belongsTo('App\Statemembers','members_id','id');
}
Please assist me where I doing wrong.
Thanks a lot for checking the question out.
Finally after a lot of strugle, I was able to find it by myself.
$mapmembers = DB::table('state_chairman_members_maps')
->join('statechairmen','statechairmen.id','=','state_chairman_members_maps.chairman_id')
->join('statemembers','statemembers.id','=','state_chairman_members_maps.members_id')
->join('statedesignations','statedesignations.id','=','state_chairman_members_maps.designation_id')
->where('chairman_id','=',$id)
->get();
Here is what I came up with.
Here I have joined 3 tables and mapped the id comming from the chairman to filter the result. I getting the results.
DB table:
Mcourse(Master course )-> contains Course Names
Lcourse(Linked
Course- courses belongs to a college) -> contains foreign key
Mcourse_Id. & college Id.
Nw the problem is
I want to display list of courses available in a college using dropdownlist.
So sql query is:
select Lcourse_Id, Mcourse_Name* from Lcourse inner join Mcourse on Lcourse_Mcourse_Id=Mcourse Id..
*Id & value pair for dropdownlist
I could do this usin createCommand..Its working pretty fine. But i cant do this usin Relations ..Help me.
Let's imagine for a minute that your Mcourse table is called courses and model for that table is called Courses, your Lcourse table is called courses_colleges and your colleges table is colleges and model for that table is Colleges
Now, You should have Courses model with relations:
public function relations() {
return array(
'colleges' => array(self::MANY_MANY, 'Colleges', 'courses_colleges(course_id, college_id)')
);
}
Your Colleges model should have similar relations:
public function relations() {
return array(
'courses' => array(self::MANY_MANY, 'Courses', 'courses_colleges(college_id, course_id)')
);
}
Now if you want to print out a dropdown with all courses available for a certain college. In your controller action method get the model of that college including its courses:
public function actionShow() {
$id = 1; // We set just some sample id. You could get it from request ofc.
$college = Colleges::model()->with('courses')->findByPk($id);
$this->render('show', array('college'=>$college));
}
Now in your view print out this:
echo CHtml::dropDownList('courses', '', CHtml::listData($college->courses, 'id', 'name'));
Where 'id' and 'name' are columns of your Courses model.
Something like that.
The error is in the listData() function in your view, specifically that you don't have a mc_Id in your Lcourse model.
As you haven't clarified the model that each of those relationships are assigned with, it's impossible to guess what you should substitute for 'mc_Id' in your view - check your Lcourse model to determine the proper column name.
I have a Linq-to-Entities query that is not complicated but requires an .include and/or projection and/or join because it must be executed in one pass.
Here is my database (Microsoft SQL Server 2008):
Table A (Customers) (contains CustomerID (customer IDs), and ZipCode (zip codes) as strings.
Table C (Categories) (contains CategoryID (categories) like "food", "shelter","clothing", "housing" (primary keys).
Table A_C is a linking table, since Tables A and C are linked as many-to-many: contains just two fields: CustomerID "customer IDs" and CategoryID (Categories), in combination as primary keys. This table is a linking table betweeen tables A and C.
Here is my query, that must be executed in just one trip to the database: I need to select all records in Table A that satisfy a condition, then filter these records depending on a 'list of parameters' that are found in the linking Table A_C--and do this all in one trip to the database. But I don't know what the length or composition of the list of parameters for Table A_C is, ahead of time--it varies from call to call. Thus this list of parameters varies method call by method call.
To give a more concrete example:
Table A has a list of customer IDs. I find the customers that live in a certain Zip code. Then, in the same SQL query, I need to find which of these customers have selected certain categories: Food, Clothing, Housing, etc, but my web method does not know ahead of time what these categories are, rather, they are passed as a list to the method: List myCategoryList (which could be 1 category or 100 categories, and varies method call by method call).
How do I write the projection using Linq-to-Entities? When the list of parameters varies? And do it all in one pass?
List<string> CategoryList = new List<string>() { "Food", "Shelter", "Housing" }; // in one call to the web service method
List<string> CategoryList = new List<string>() { "Food", "Clothing" }; //could be a second call--it varies and I don't know ahead of time what the List will be
So how can I do the SQL query using Linq-to-Entities? In one pass? (Of course I could loop through the list, and make repeated trips to the database, but that's not an optimal solution I am told). Projection,.Include are keywords but surfing the net yielded nothing.
Here is a crude guess, just to get ball rolling:
public void WebMethod1 (CategoryList)
{
using (EntityFramework1 context = new EntityFramework1())
{
/* assume CategoryList is a list of strings passed into the method and is,for this particular call,something like: List<string> CategoryList = new List<string>() { "Food", "Clothing" }; for this call, but in the next call it could be: List<string> CategoryList = new List<string>() { "Food", "Shelter", "Housing" } */
string ZipCodeString = "12345";
string customerIDString = "E12RJ55";
var CustomersFromZipCodeHavingSelectedCertainCategories = from x in context.A_C
where x.A.CustomerID == customerIDString
where x.A.StartsWith(ZipCodeString)
where x.A_C.Contains(CategoryList) //???? This is clearly not grammatical, but what is?
select x;
}
/*
my problem is: I want to filter all records from A that contain a zipcode 12345, and that also have a certain CustomerID "E12RJ55" from table A, but further filter this set with all such CustomerIDs in linking table A_C that contain the categories "Food" and "Clothing".
How to do this in one pass? I can do this quite easily in multiple passes and trips to the database using code, but somebody in this thread here http://bit.ly/rEG2AM suggested I do a Join/projection and do it all in one fell swoop.
*/
I will also accept SQL answers since it might help yield a solution. This question btw is not difficult I believe--but I could not find an answer on the net.
EDIT: with answer and credit to david s.
I thank you for the answer david.s. Here is what worked, slightly different than the answer by david.s, in that I am using the linking table (bridge table) called “Customer_Categories” that is between the table Customer and Categories and contains the primary key of each (as is required for many-to-many relationships). This bridge table is what I called "A_C" in my original answer, and here has ints rather than strings but is the same thing. Intellisense picked up this table and I used it, and it works. Also keep in mind that CategoryList is a list of ints, List CategoryList = new List();, yet amazingly it automagically works inside this SQL-to-Entities query:
Var CustomersFromZipCOde = context.Customers.Where (custo => custo.CustomerID==customerIDString && custo.ZipCode.StartsWith(ZipCodeString) && custo.Customer_Categories.Any(categ => CategoryList.Contains(categ.CategoryID)));
//gives the right output, incredible.
First of all i would like to say that even if you explanation is very long it is not very clear. You would like a simple Linq-to-Entities query but you don't give the Entities, you only speak of tables in your database.
Assuming you have the following entities:
public class Customer
{
public string CustomerID { get; set; }
public string ZipCode { get; set; }
public virtual ICollection<Category> Categories { get; set; }
}
public class Category
{
public string CategoryID { get; set; }
public virtual ICollection<Customer> Customers { get; set; }
}
Your query might look like this:
var CustomersFromZipCodeHavingSelectedCertainCategories =
context.Customers.Where(
customer => customer.CustomerID == customerIDString &&
customer.ZipCode.StartsWith(ZipCodeString) &&
customer.Categories.Any(
category => CategoryList.Contains(category.CategoryID));
More info on other ways to do this here:
http://smehrozalam.wordpress.com/2010/06/29/entity-framework-queries-involving-many-to-many-relationship-tables/