When working with outside systems, like making calls to an external database, web API, etc., we typically use async operations to optimize our code while waiting for these external systems to respond, especially if they take more than a few milliseconds. So far, we have performed all synchronous operations, but Dapper.Transaction also fully supports async versions of all of the primary methods.
The following is the async version of the GetAllAuthors method.
private async static Task<List<Author>> GetAllAuthorsAsync()
{
using (IDbConnection connection = new SqlConnection(ConnectionString))
{
connection.Open();
using (var transaction = connection.BeginTransaction())
{
IEnumerable<Author> results = await transaction.QueryAsync<Author>("SELECT * FROM Authors");
return results.ToList();
}
}
}
Here you can see that we are using the QueryAsync method. Now to call this async method, we need to call it from an async Main method.
static async Task Main(string[] args)
{
var authors = await GetAllAuthorsAsync();
foreach (var author in authors)
{
Console.WriteLine(author.FirstName + " " + author.LastName);
}
}
The following example inserts a single author asynchronously using ExecuteAsync
private static async void InsertSingleAuthorAsync()
{
using (IDbConnection connection = new SqlConnection(ConnectionString))
{
connection.Open();
using (var transaction = connection.BeginTransaction())
{
Author author = new Author()
{
FirstName = "William",
LastName = "Shakespeare"
};
string sqlQuery = "INSERT INTO Authors (FirstName, LastName) VALUES(@FirstName, @LastName)";
int rowsAffected = await db.ExecuteAsync(sqlQuery, author);
}
}
}
Let's run your application, and you will see that we are getting the same results. It is just that behind the scenes that we did it asynchronously this time.