Dapper Tutorial - Knowledge Base (KB)

.NET SqlConnection and SqlCommand

I use SqlConnection and SqlCommand classes in my project with Dapper ORM but I've got a strange problem. When I use SqlCommand for inserting a row in a db table it always work correct and when I select updated data form tables everything is fine but after...

Session-Per-Request with SqlConnection / System.Transactions

I've just started using Dapper for a project, having mostly used ORMs like NHibernate and EF for the past few years....Typically in our web applications we implement session per request, beginning a transaction at the start of the request and committing i...

Why doesn't Dapper dot net open and close the connection itself?

Dapper implicitly expects a connection to be open when it uses it. Why doesn't it open and close it itself? Wouldn't this simply connection management?...I ask because a co-worker and I have been going back and forth on the nature of what goes on behind t...

Remembering SQL connection state in .net?

Beside's the old known fact that ...connection.Close()... vs ...connection.Dispose()... are the same - except that running ...Close()... over a disposed connection raises an exception while running ...Close()... over a closed connection - is OK - I stil...

Trying to understand erratic behavior of DB Connection used by Dapper

I need some help better understanding how Dapper handles DB Connections, and why DB Connection isn't being properly disposed of. I have coded around the different possible cases. In my code, I am checking to see if the _connection is null, and creating a...

How to store a sql result to a variable in C# using Dapper.NET

I'm using ...dapper... in my project, a beautiful tool for storing the ...SQL query... results to a ...List... and this working good....I wrote a ...SQL query... to fetch a record from database and store the result in a variable, I tried using ...dapper..

C# Identity UserManager CreateAsync then FindByEmailAsync returns User with Id=0

Identity with Dapper....My user in my Identity is of type IUser< int >...When a user Registers, I create a user in my AccountController:...Register POST:...if (ModelState.IsValid) { user = new MySiteUserRecord { UserName = model.UserName, ...

Does QueryAsync calls OpenAsync with Dapper?

I have come upon a bit of code that looks like this (it is based of Dapper tutorial):...await using var con = new SqlConnection("some connection"); if (CancellationToken.IsCancellationRequested) await con.OpenAsync(CancellationToken); return await con.Que...

Insert many rows with Dapper

what's the best solution to insert many rows into the SQL Server with Dapper? When I have got about 8k records my databaseconnection timeouts and fails....In my application at the end stage I have got lets say a list of tables, where each table got list o...

Exception with message 'No columns were mapped' using Dapper Extensions

I have a ...class... which implements some ...interface...:...public interface IDb {} public class DbModel : IDb {} ...After this I use Dapper Extensions to insert the object into the DB. This code works well:...var obj = new DbModel(); sqlConnection.Inse...

Difference between connection.OpenAsync and connection.Open when using Dapper QueryAsync method

What is the difference between using connection.OpenAsync() and connection.Open() when using dapper's QueryAsync method....Async:...public async Task<IList<Product>> GetListAsync() { using (var connection = new SqlConnection(_connectionString)...

Difference between a 'using statement' for every SqlConnection and single SqlConnection as private property in C# data layer

When implementing the repository pattern using Dapper ORM I am currently doing the following:...private readonly ConnectionStrings _connectionStrings; private IDbConnection _db; public CustomerRepository(IOptions<ConnectionStrings> connectionStrings) { ...

Is connecting to a database using SqlConnection() AND a Connection string safe?

I am using the following code in conjunction with dapper ORM to connect to a database : ...using (IDbConnection db = new SqlConnection(ConnectionString())) { return db.Query<object>(Sql).ToList(); } ...The connection string contains database name and logi...