Sure – as long as your enum agrees, i.e. enum MyEnumType : byte { Foo, Bar, Blip, … } then it will all work automatically. (this limitation is by design, and shared with LINQ-to-SQL as it happens) Alternatively, if the enum is : int and can’t be changed, cast it in the SQL: SELECT …, … Read more
My problem is also that I have cars in generic list List Cars and I want pass this list to stored procedure. It exist elegant way how to do it ? You need to convert your generic list Car to a datatable and then pass it to storedprocedure. A point to note is that the … Read more
ExecuteScalar was just added in 1.28: https://www.nuget.org/packages/Dapper
I am assuming that you are using latest version of Dapper. With Dapper, there are two ways to manage connection: Fully manage yourself: Here, you are fully responsible for opening and closing connection. This is just like how you treat connection while working with ADO.NET. Allow Dapper to manage it: Dapper automatically opens the connection … Read more
There’s a much easier solution now in a similar question, but it is about string. For DateTime: SqlMapper.AddTypeMap(typeof(DateTime), System.Data.DbType.DateTime2); This must be applied before any database call like INSERT. You can put it in your Main or Startup class, or any place that runs on Startup to configure data access. SqlMapper is a static class … Read more
Please don’t do this! It’s fragile, and introduces a gaping sql injection vulnerability. If you can return your count for a given table with one line of very expressive code, and no vulnerability, why make it method? Do this instead: DapperConnection.ExecuteScalar<int>(“SELECT COUNT(*) FROM customers”); // You will be happier and live longer if you avoid … Read more
Implement your model with properties, not fields: class MyAccount { public string Name { get; set; } public int Priority { get; set; } } Dapper looks at the properties of the object to get parameters, ignoring fields. Anonymous types work because they are implemented with properties.
I have just submitted a fix to the repository that allows any of the following to work correctly: by object (this worked previously): values.AddDynamicParams(new { ids = list }); or, by single name: values.Add(“ids”, list); or, as a dictionary: var args = new Dictionary<string, object>(); args.Add(“ids”, list); values.AddDynamicParams(args); I have not yet deployed to NuGet. … Read more
I just added a test for this: class Student { public string Name {get; set;} public int Age { get; set; } } public void TestExecuteMultipleCommandStrongType() { connection.Execute(“create table #t(Name nvarchar(max), Age int)”); int tally = connection.Execute(@”insert #t (Name,Age) values(@Name, @Age)”, new List<Student> { new Student{Age = 1, Name = “sam”}, new Student{Age = 2, … Read more
So, can somebody please help me understand why leveraging the same overload inside of those other methods is failing with that error? Precisely because you’re using a dynamic value (param) as one of the arguments. That means it will use dynamic dispatch… but dynamic dispatch isn’t supported for extension methods. The solution is simple though: … Read more