“Tasks” table: “Task History” table: Sql query: Which tasks were completed in the last 30 days? Q: What is the equivalent LINQ expression for this SQL query? Answer This query should do what yo want:
Tag: entity-framework
How to convert SQL query to Linq in Entity Framework 6?
How can I convert this SQL query to a linq expression? Select distinct Clients.Id From Clients Join Orders On Clients.Id = Orders.ClientsId and Orders.Date < DATEADD(DD, -Clients.Term, CAST(…
Selecting multiple columns for updating in Linq
I have a products table which contains thousands of products. I want to update only two columns (price, isAvailable) of this table. So is there is a way to select only those two columns from this table? This is the code that I am using. But I don’t want to select all columns. I have tried this But this …
PostgreSql and EF – Getting ‘duplicate key’ error while doing ‘ToDictionary’ after grouping
Here is my query. UserName column is citext, having non-unique index on it. var logs = Db.Logs .GroupBy(x => x.UserName) .ToDictionary(g => g.Key, g => g.Max(m => m….
How to convert this Entity Framework query to a SQL Server query
I have a query which is written in format like this: How do I convert this query to a plain SQL Server query to see what its output is? Answer In Entity Framework there are a few ways to look at the SQL a query generates. Note: All these ways will use this query: Cast IQueryable to an ObjectQuery and
c# ef core RemoveRange contraint violation
Hi I have a complex db with many tables and relations what we want to do is to copy all tables from a database to another but only taking rows starting from one table (salesorder) and going down following relations. So I avoided the .Include, and use IQueryable queries (one for each table) there is no problem…
FromSqlRaw injection EF Core 3.0
I am wondering how safe the fromSqlRaw method is. I am doing the following in my code, where the person id is a parameter from the method itself: Is this code safe to SQL injection? And is there other security vulnerabilities that I should know of when using this? Answer Use proper parametrization for your in…
How many SQL Queries will be executed in the database through this EF
I have the following and want to know how many queries will be executed in the DB through this EF? private static dbContext dbc = new ProfileDBC(); private static IQueryable GetProfile(…
Why there is no GroupBy clause in internal SQL of Entity Framework linq query?
In documentation of Entity Framework: https://www.entityframeworktutorial.net/querying-entity-graph-in-entity-framework.aspx in section regarding GroupBy we can read that following code: executes internally following SQL: Why there is no GroupBy clause in SQL? If there is no GroupBy clause needed, can’t we ju…
How to use Group By with Task<IEnumerable> in LINQ
I am new to the entity framework and LINQ. Trying to learn it by example. I have an Entity called “Participant” as below: I am trying to use Group by and return the result as Task<IEnumerable<Participant>>. The Sql Query that I found the is : SELECT Count(Id) as #, Zip FROM [database].…