C# – Check if a string contains any substring from a list

There are many different scenarios where you might want to check a string against a list of substrings. Perhaps you’re dealing with messy exception handling and have to compare the exception message against a list of known error messages to determine if the error is transient or not. When you need to check a string … Read more

C# – How to use Polly to do retries

Whenever you’re dealing with code that can run into transient errors, it’s a good idea to implement retries. Transient errors, by definition, are temporary and subsequent attempts should succeed. When you retry with a delay, it means you think the the transient error will go away by itself after a short period of time. When … Read more

How to do retries in EF Core

EF Core has built-in retry functionality. To use it, you can call options.EnableRetryOnFailure(), like this: The retry logic is contained in execution strategy classes. The above code is using the default execution strategy class (SqlServerRetryingExecutionStrategy). When you execute a query, it goes through the execution strategy class. It executes the query and checks for transient … Read more

C# – How to unit test code that reads and writes to the console

When you’re unit testing code that uses the console IO methods, you’ll need a way to automate the input and a way to capture the output. There are two ways to do this: Redirect the console IO. Wrap the console IO method calls and mock out the wrapper. In this article, I’ll show how to … Read more

PowerShell – How to use Select-String to search files for a pattern

In this article, I’ll show how to use the Select-String PowerShell command to search files in a directory for a regex pattern. I’ll first explain the basic syntax, and then I’ll show a few common search scenarios. Pattern, path, and alias Select-String has two main parameters: pattern and path. The pattern is what you want … Read more

C# – Pad a 2D array on all sides

Padding a 2D array on all sides means adding new rows on the top and bottom, new columns on the left and right, and then copying the original elements to the center of the padded array. It looks like this: There are two approaches for copying the elements. You can either copy individual items in … Read more

C# – How to use table-valued parameters (TVP) with ADO.NET, Dapper, and EF Core

Table-valued parameters (TVP) allow you to send multiple rows of data as a parameter into SQL queries. TVPs are flexible. They can be used in both raw SQL queries and with stored procs, and can be used in all types of queries, from inserts to selects. In this article, I’ll show how to use TVPs … Read more