The “Cannot access a disposed object” exception in ASP.NET Core, especially when using Entity Framework’s DbContext, is a common issue developers face. This article explores the root causes, prevention strategies, and best practices to avoid this error in modern ASP.NET Core applications.
The ObjectDisposedException typically occurs when an attempt is made to use an object that has already been disposed. In the context of ASP.NET Core and Entity Framework, this often involves the DbContext. The error message generally looks like this:
Continue reading “Cannot access a disposed object in ASP.NET Core when injecting DbContext”System.ObjectDisposedException: Cannot access a disposed object.
This post explaines how to add index to EF Core with extra columns included from code.
When creating indexes with code first migrations in Entity Framework Core you can create an index on a table by adding the following to your DbContext:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<table>()
.HasIndex(t => new { t.Column1, t.Column2}); }
Continue reading “Add Index with Include Entity Framework Core”
In a scenario where we were using SQL server as a queue, before publishing events to external queues, we wanted the data to be processed only once and in order, even with multiple processors for failover. When reading from the table we wanted to lock the records and block other processors from reading those records, while being processed. This is called Pessimistic Concurrency, unfortunately Entity Framework Core does not support this out of the box. To realize Pessimistic Concurrency you need to write your own SQL queries directly on the database (The solution is database type bound, in this case Microsoft SQL server). This blog post will show how it can be accomplished.
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Out of the box Entity Framework does not support Full Text Search. To do Full Text Search you have a number of options to get it working. In this blog post I’ll describe a method to get Full Text Search working using a table valued function. The method does the Full Text Search in a table valued function that returns an id list, the returned ids can be used to filter the records from an actual table.
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