I have requirement like I need to expand the table of different database.
For example we have two model product and department. Both are in different database.
product table is in database1 and department table is in database2.
How can I expand database2..department under database1..product with odata $expand.
I am using C#,.netcore and EFCore. Please help me how can I do it with odata?
Related
I have database with different tables. But I can't get access to some tables, and I'm curious why? For example, there is Projects table and Users table in database, and I need to get list of all users that are in specific Project by Id. These tables have many to many relationship, so there is joining table with ProjectId and UserId. It's logic to use some Join to get users that I need from table Users with help of this joining table from db. But how can I make Join when my DbContext doesn't have joining table? How can I get access to joining table using DbContext, or maybe there are some different ways to get list of users by project id?
If someone have similar problem, here is a simple way to use all the data from collections in model
var project = _db.Projects.Include(x => x.Tickets).ThenInclude(y => y.Users).SingleOrDefault(p => p.Id == id);
so after that you gonna have your model and all the data from collections that you need
ProjectUser - is joining table, use for link two tables. This tables must have (usually) Collection for access to this many-to-many data.
So you can will have collection of users for this project. And doing filtering by users from your Ticket (example from image).
Yes, exists few different ways - setting with ef fluent, or attribute, or dbcontext. Better to find complete guide for many-to-many setting in your application.
I have a DirectQuery table (Weather) which is sourced from an Azure SQL server. I would like to join this with an Imported table (Buckles) from an Excel sheet sourced from SharePoint Online.
Both tables have a UID field that is made up of a concatenation between a SiteID and timestamp. The UID field is named differently for each table.
I have created a One-To-Many relationship between the two tables.
I have tried to create a new DAX table using a NATURALINNERJOIN on Weather and Buckles but I get this error:
"No common join columns detected. The join function 'NATURALINNERJOIN' requires at-least one common join column."
I am confident it is not a problem with the underlying data because I've created a new imported Excel table (Test) with a selection of the data from Weather and I'm able to successfully create the join on Test and Buckles.
Is the joining of DirectQuery and Imported tables supported? I feel like this may be a type casting issue, but as far as I can see, both UID fields are set as Text.
The UID field is named differently for each table.
I suspect this may be the issue. NATURALINNERJOIN looks for matching column names
and if the two tables have no common column names, an error is returned.
Note that if you create a calculated DAX table using a DirectQuery source, I don't think that table will still act like DirectQuery. If I understand correctly, it will materialize the calculated table into your model and DAX that references that calculated table no longer points back to the SQL server (and consequently will only update when the calculated table gets rebuilt).
We have a web portal in our company that is written in asp.net MVC . right now each department have their own database but we want to avoid having multiple database because the database scheme is the same only it has diffrent data inside for each department.like each department has their own projects etc. how the database model should be changed in such a way to avoid having multiple database ?
also we want to share some elments like projects between diffrents department. how it could be done ?
The single database that you have in mind would have to have its table re-designed such that you would be able to tell, for each record in each table, what department the record relates to. Essentially you would need to add a "DeptId" column to each root-level table. By root level table I mean only the parents of foreign key relationships. Eg, if you have an OrderHeader and OrderLines, only the OrderHeader table would need to have this DeptId column. The lines relate to the header, so you won't need to add this column to the lines table as well. Alternatively, if you have a Customer table, such that each customer belongs to only one department, then you would add the DeptId column to this customer table and then you won't need it on the OrderHeader table (since order header should be referencing Customer table)
Those tables/elements that you want to share between databases just would not have the DeptId column added to them.
I want to show list of order details including count of ordered material and name of customer.
There are three tables order_details, order_item_details and customer_details
for this scenario how to create view model and linq
my db structure
customer_details === customer_id,customer_name
|||||
order_details === order_id, order_number, customer_id
|||||
order_item_details === order_item_id, order_id , item_id
and i want to show------
order_details.order_number, customer_details.customer_name, count(order_item_details.order_item_id)
Create a view in your database that links the three tables appropriately, then point your ORM (EF?) at the view, and you will get a read-only view of your table with appropriate models. If what you're doing is particularly complex, you can create a stored procedure and use the same technique.
If you are in fact using Entity Framework, here's an SO answer that tells you how to create custom entities in EF 4 (first answer by Kevin Castle):
Entity framework 3.5, mapping stored procedure results to custom entity
So I am working on an MVC project to put to work the studying I have been doing. I am wrestling with the concept of Database Table relationships and foreign keys. I am working on a simple ecommerce site (displays products, shopping cart, user accounts..etc).
I have the following tables to start out with:
1) Products
2) Categories
I setup the Products and Categories tables to have a ProductId and CategoryId respectively. In my MySQL db, I created a FK on the Products Table to relate to the CategoryId field on the Categories table (I am not sure this was correct to begin).
My expectations for the way the database would handle the table relationship: I didn't want the DB to do anything with the products table if I deleted a category out of the Categories table, or vise versa. The only thing would be that the category field in a Product would be blank (or default) if their category was removed.
Finally, do I have to do anything in my entity classes such as in the Products class, add the ProductId to the Category.ProductId?
Eventually, when I Orders and Users to the project, I can see a relationship where each user -> many orders -> each order has many products -> and each product is in one category.
But I am having a hard time understanding how or if I should be setting up a Foreign key relationship in the two current tables of Products and Categories and if so how to setup my entity class in relation to that FK.
Any advice.
It has been my experience (with L2S) that you don't want to specify any relationships between tables. I have simply done the PK, FK logic myself. This keeps the L2S generated objects simple and is most likely the way you worked with them before in SQL. That, at least, is the case for me.