C# – Using SQL transactions with Dapper

Using TransactionScope is the simplest way to execute multiple SQL commands in a transaction. Here’s an example of how to use it: When you call TransactionScope.Complete(), it commits the transaction. If you don’t call Complete(), it’ll rollback the transaction once it leaves the TransactionScope block. This keeps the code nice and clean and works well … Read more

Case sensitivity in SQL Server

In SQL Server, the collation property controls case sensitivity. Case sensitivity affects sorting and queries (even the column names must match exactly if you’re using a case-sensitive collation at the database-level). The default collation when you create a database in SQL Server is SQL_Latin1_General_CP1_CI_AS. The CI stands for case-insensitive, which means SQL Server databases are … Read more

SqlException: Cannot insert explicit value for identity column

When you have a table with an identity column, and you try to specify the value for identity column when inserting a record, you’ll get the following exception: Microsoft.Data.SqlClient.SqlException (0x80131904): Cannot insert explicit value for identity column in table ‘Movies’ when IDENTITY_INSERT is set to OFF. This error means you have an identity column in … Read more

EF Core – How to add indexes

In this article, I’ll show how to add indexes using EF Core. If you’re not sure about why you would need indexes, take a look at this article explaining how indexes greatly improve query performance. Add an index with a single column The simplest way to add an index is to by adding the [Index] … Read more

EF Core – Add a foreign key

In this article, I’ll show how to add a foreign key using EF Core. Then I’ll show how foreign keys affect inserts and deletes. How to add a foreign key A Show has one or more Episodes. In this section, I’ll show how to link these two tables together to enforce the 1-to-many relationship. In … Read more

C# – Exception filters – conditionally catch exceptions

In C# 6 they added exception filtering. This allows you to conditionally catch exceptions. To filter exceptions, you use the when clause after the catch clause, like this: Any SqlException that doesn’t meet the condition will not be caught. Previously, without exception filtering, you’d have to handle that scenario in the catch block and rethrow, … Read more