Filter Parent / Child Table In Linq Query Based On Entities In Child Table?

Jul 9, 2010

I have a table (Projects) which is linked to projectVersions on projectID..projectVersions contains several columns on which I'd like to filter a returned project (and associated projectVersions) list. For example there is a "capacity" column and a "country" column. I am doing a filtered list of projects on one page and I'd like to include all projects where any one of the associated projectVersions has a capacity of 750ml and a country of "France" for example.It may be that a particular parameter is not set and so I pass a zero to indicate not to filter on that.I guess this needs some kind of subquery as when I try and do something like this: [code] it doesn't work as the "xxx" bit, being one-to-many, expects me to specify an item to get at the entities within and yet I want to query where ANY of the associated versions match one of the criteria.

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C# - LINQ To SQL Join Two Tables To Select Parent Table Twice Based On Two Different Columns From Child Table?

Aug 23, 2010

I have two tables Employees and CafeLogs. Some employees can be cashiers and also customers at the Cafe shop.

Table structures:

Employees: EmployeeId(PK) , FirstName, LastName
CafeLogs: LogId (PK), CashierId, EmployeeId, Value, => CashierId and EmployeeId are the data from column EmployeeId of Empoyee table

Table relationship:

Employees 1:N CafeLogs (CashierId (FK))

[code]....

Right now I know how to select only LogId, Employee's name, and , Value, not with Cashier name yet.

Dim query = From log In db.CafeLogs _
Join emp In db.Employees On emp.EmployeeId Equals log.EmployeeId _
Select log.LogId, emp.FirsName, emp.LastName, log.Value

Creating DataRelation With Parent And Child Tables And Generating Xml With Subnodes For Child Table?

May 21, 2012

Dim obj_DataTable As New System.Data.DataTable("Category")
Dim obj_DataSet As New DataSet()
'Declaring the array of DataColum to hold the Primary Key Columns

[code].....

VS 2008 Filter The BindingSource Based On Text Matches Between Any Of The Fields In The Child Table

Jul 16, 2011

I have a database with a table that is a child to many other tables. I am using this child table as a datasource for a datagridview. I am using comboboxes to display specific fields in any parent tables, instead of the user seeing the foreign key. Everything is fine. However, I would like to filter the BindingSource based on text matches between any of the fields in the child table and the corresponding fields of the parent tables.

[Code]...

Refresh Table Adapter When I Have A Child Table Attached With Parent Table?

Dec 21, 2011

I have a data table whose one column is related to a column of another table. I have a listbox in a form which shows a column (which is sorted by another column value by ORDER clause) of the parent table and other columns are in textboxes. The child table is represented by a datagrid. When I add a new item in parent table and click save, the newly created item is listed at the bottom of the listbox violating my ORDER clause. When I wrote some codes to fill data again after updating, it shows an error message[code]...

Linq To Entities Query With Child Objects?

Oct 13, 2011

Basically I have the follwing:Dim ctx As New AdminCoreEntities Dim roles = (From r In ctx.Roles where r.Name.StartsWith("cust") Select r) 'list of System .Linq.IQueryable(Of AdminCoreModel.Role)

[code]...

The error i get when i run this is: Unable to cast object of type System.Data.Objects.ObjectQuery`1[AdminCoreModel.Role] to type AdminCoreModel.Role

Basically I have a many to many situation and I try to get all the Quicklinks objects queried by their roles and not quite sure why EF will cast to a single AdminCoreModel.Role when i.Roles is a collections of objects.

Show Parent Table And Child Table In Datagridview?

Jun 18, 2009

in DataSet ds I have "tbl1" as parent table and "tbl2" as childtablehow to show both table in datagridview if column id in "tbl1" related to column headerId in "tbl2" ?

Viewing Child Table With Parent Table In Datagrid?

Jun 17, 2009

I have a SQL Data Base. I have created a relation between these tables. Problem is when i drag and drop it on Data grid i get only Parent table columns but i want to sea them both like this.

- Parent Table Row
- Child Row 1
- Child Row 2

[code].....

VS 2008 Updating Child Table Before Parent?

Jan 11, 2011

I have a situation where a database table is updated with records inside a loop. Every record in this table has a parent child relationship with another table. This child table is also updated subsequently inside the same loop.I am creating the datatable for Parent table and adding records inside the loop, but committing the records in the database (using SqlCommandBuilder) outside the loop only once.

Inside the loop I am also calling the function for updating records in the child table. Because the adaptor and datable objects are created inside the child table function, I need to commit records in child table inside the function only. So this happens before commit of parent table. Because there is a PK-FK constraint in the database, an error is generated.

Simplest solution would be to bring all code inside one function. But I don't want to do that. Besides this parent child relations can go upto any levels.

[Code]...

Loop Through Child - Bind Textbox To Field Of Parent Table

Mar 22, 2010

First I have 2 tables, for example Customer and Orders, and in the database there is a foreign key relation between both. For clarity Orders have a foreign key field to the primary key of Customers, thus Customer is the parent and Orders is the child table of the relation. My application is a Windows Form application, and I add a dataset to the project, in which I drop the 2 tables, and the relations between the 2 tables is automatic added. Now I will om a form loop through the Orders table (witch is the Child table) and show in a textbox some fields of the Orders table and also the Name field of the related record of the customers table. Regarding binding a textbox fo a Orders field I do it this way,

Dim myDs As New DataSet1
Dim myAdpCustomer As New DataSet1TableAdapters.CustomerTableAdapter
Dim myAdpOrders As New DataSet1TableAdapters.OrdersTableAdapter
myAdpCustomer.Fill(myDs.Customers)
myAdpOrders.Fill(myDs.Orders)
Dim myBindingSource As New BindingSource
myBindingSource.DataSource = myDs.Orders
myBindingNavigator.BindingSource = myBindingSource
TextBox1.DataBindings.Add("Text", myBindingSource, myDs.Orders.OrderIDColumn.ColumnName)

But now I can't find how to bind a textbox to a field of the Customers table witch is the Parent table of the relation.

Showing Data From Child Table By Clicking On Parent Record?

Apr 4, 2009

Instead of connecting to database,I create datacolumns of two data tables.assign foregin key constraints and primary keys to the columns.Add these datatables to dataset and create relationship between them.Now by using RowFilter property,how to display the child table in a datagrid by clicking on parent record in another datagrid?Accept and Award Points Accept as Solution

Ensure That The Currently Selected Row ID In Parent Table Automatically Appears In Child Form?

Feb 26, 2009

How can I ensure that the currently selected row ID in Parent Table automatically appears in my child form when I create a new row in the Child Form.I am using VB 2008 Express I have a Stored Procedure for the chiled table called "Files" can I do it from there:-

ALTER PROCEDURE dbo.CreateFile
(
@FileName varchar(50),
@DateCreated varchar(50),

[code]....

Postgresql - Populate Tree View For Parent Child Relation In Same Table?

May 1, 2011

The database strutcure is:

Id Name ParentId
1 File NULL
2 Open 1
3 Save 1

[Code]....

I am using the database PostgreSQL.

Require Assistance Making A Menu From A Single Parent/Child Table?

Oct 25, 2010

I have a single table that holds my Categories

CatID, CatName, ParentID

I have often used this layout to show Root Categories where the ParentID IS NULL. I would like to be able to create a vertical Menu (using a repeater and an <UL><LI> that displays the Root Categories and ideally, a collapse panel that would expand with the subcategories. Given the above Table format, it is also easily possible to make the hierarchy unlimited.

how to make a single dataset that understands the Child relationship.

Interface And Graphics :: MDI Parent / Child - Child To Check To See If It Is The Last Child Object Before Closing

Feb 18, 2011

Im working with MDI parent/child objects. when closing the child objects i need the child to check to see if it is the last child object before closing. i couldn't find anything on google, maybe im searching for the wrong thing.

Asp.net - Select Query In LINQ Based On Foreign Table

Mar 2, 2011

I have 2 Tables , OrderDetails and Requests In my LINQ to SQL dbml file. OrderDetailsID is a foreign key in Requests Table.

I want to write the query to get the sum of UnitCost from OrderDetails based on OrderId. And If there is a row in Requests Table for each OrderDetailsID, and the Requests.Last.RequestType="Refund" I want to reduce the total refund amount from the main sum otherwise If there is no row based on OrderDetailsID, add to sum.

Here is the way I implement that. I am looking to prevent using "For each".

iRefund = (From od1 In dc.OrderDetails _
Where od1.OrderID =1 _
Select od1.UnitCost).Sum

[Code]....

Select Query In LINQ Based On Foreign Table?

Mar 4, 2009

I have 2 Tables , OrderDetails and Requests In my LINQ to SQL dbml file.OrderDetailsID is a foreign key in Requests Table.I want to write the query to get the sum of UnitCost from OrderDetails based on OrderId.And If there is a row in Requests Table for each rderDetailsID, and the Requests.Last.RequestType="Refund" I want to reduce the total refund amount from the main sum otherwise If there is no row based on OrderDetailsID, add to sum

Update One Entity Based On Results Of Another LINQ-to-Entities Query

Apr 9, 2011

I have the following LINQ-to-Entities query:[code]This will give me all the resident assignments for the current year/term. Then I have this LINQ-to-Entities query:[code]This will give me all the rooms. I want to iterate through the assignments and based on what room is assigned update the occupancy in reset_occupancy. I'm not 100% sure how to accomplish this. Here is my pseudo code of what I want to accomplish:[code]

Update One Entity Based On Results Of Another LINQ-to-Entities Query?

Dec 15, 2009

I have the following LINQ-to-Entities query:

' Get all the residency assignments that match the term/year.
Dim assignments = From p In dbContext.Residents _
Where p.semester = term _

[code].....

Connect Table Like America And Child Table Like State?

May 3, 2010

how to connect my table like america and child table like State i want to add sub node or childto th tree view?

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Aggregating Parent/child Tables Using Linq To SQL?

Sep 18, 2009

I'm having a nightmare with LINQ. I've got a table of Projects, and each project has many InvoiceHeaders. The Invoice header had a field AmountNet - the value of the invoice.

I want to retrive, for arguments sake, all of the fields from Projects, with the count of invoice headers and the sum of AmountNet. I.e. list of my projects, how many invoices I've raised and the value.

Doesn't sound hard does it.... well, I've just spent the best part of two hours charging through Google and SO to find a solution.

[Code]...

C# - LINQ - Select All In Parent-child Heirarchy

Mar 12, 2012

I was wondering if there is a neat way do to this, that DOESN'T use any kind of while loop or similar, preferably that would run against Linq to Entities as a single SQL round-trip, and also against Linq To Objects. I have an entity - Forum - that has a parent-child relationship going on. That is, a Forum may (or in the case of the top level, may not) have a ParentForum, and may have many ChildForums. A Forum then contains many Posts.

What I'm after here is a way to get all the Posts from a tree of Forums - i.e. the Forum in question, and all it's children, grandchildren etc. I don't know in advance how many sub-levels the Forum in question may have. (Note - I know this example isn't necessarily a valuble use case, but the Forum object model one is one that is familar to most people, and so serves as a generic and accessible premise rather than my actual domain model.)

SQL Server Query Combination - Get Rows From A Table Based On The Value Of A Field In Another Table

Feb 23, 2011

I have a query that I have to run that requires me to get rows from a table based on the value of a field in another table (which I have gotten earlier). I currently have it done like this (simplified).

[Code]...

How To Work On Both Parent And Child Form Without Closing Child

Apr 10, 2011

i have created two forms A and B when button in form A is clicked B is invoked when B is running its not possible to work on A until i close form B. How can i work on A without closing B

Passing Data From Child To Parent Form Which Is A Child Of Another One

Apr 17, 2012

i have three forms

when i click button1 on form1=====> form2.showdialog()
then click button 1 on form2 =====> form3.showdialog
then click button 1 on form 3 =====>

[code].....

VS 2010 How To Load Child Data When Query A Parent

May 30, 2010

i have a one two many relationship on a form that loads empty so that the user have to do a search in order to populate the data into the form. To acomplish this, i created a filter (query) in the dataset. The filter works fine for the parent data, but how can i load its corresponding child data?

This is the code generated automatically when i created the filter in the DataSet:

VBCode

Try Me.TblConfidencialesTableAdapter.Buscar_Confidencial(Me.ConfidencialesDataSet.tblConfidenciales, TablillaConfidencialToolStripTextBox.Text)
Catch ex As System.Exception

[Code]....

Order A Collection Based On A Child Property Using LINQ Or A Lambda?

Jan 26, 2012

I get the following string expression provided:"ChildObject.FullName" ...where ChildObject is an instance property on the MyObject1 type.ChildObject has a property named "FullName" and I want to sort a collection of type "MyObject1" based on this child properties "FullName" value.

I can do this all day long on properties directly on MyObject1 but I run into 2 challanges when doing it on a child instance and I can't get all the pieces working. The main 2 challanges are:

MyObject1 has a few different child property types so I can't hardcode the type for ChildObject. The string could be of any type.The sort expression is a String and not a known type.Above the value returned from the last line in the expression (if I run the code outsode the OrderBy method, does provide me the 'FullName' information I need. So the code must be close, but it still does not work.

Any ideas on how I can accomplish this? What I am trying to prevent is hardcoding a series of 'If' blocks on the child's type to then hardcode in its type to the sort or OrderBy method.

Cannot Filter A Binding Source Based On A Linq Query

Feb 3, 2010

I've got a datacontext and created a binding source using LINQ to sql but cannot filter said bindingsource. The supportsfilter of the bindingsource is set to false ? why ? I can't find any info to say that I cannot filter a binding source based on a linq query.[code]

Linq To Xml Query Returning A List Of All Child Elements?

Mar 8, 2010

I have got an xml document which looks something like this.

<Root>
<Info>
</Info>
<Info>

[Code]...

How can i write a linqToXML query so that it returns me an IEnumerable containing each child element, in this case all five child elements of , so that i could iterate over them. The order of child elements is not definite, neither is number of times the may appear.

Bind Child/Parent Instead Of Parent/Child?

Apr 28, 2009

Applications_Type is a lookup table for Applications.What I am trying to do is provide a drop down list of applications and a label that displays the selected application type.[code]...

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