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Hi,

I have a scenario where the parameters for a query/command are created dynamically. This means that, in order to use the object mapping functionality such as the one below is not possible out of the box.

connection.Read<T>( "select @p0, @p1", new { p0 = "value1", p1 = "value2" } );

To get around this issue, I am doing some nasty things that essentially turns a IDictionary<string, object?> into an anonymous type.

It would be a great addition if we could construct a IDictionary<string, object?> and use that as the parameters argument.

connection.Read<T>( "select @p0, @p1", new Dictionary<string, object>
{
    { "p0", 1 },
    { "p1", "2" }
} ); 

Using Execute does not return the number of rows affected, How to get the number of affected rows？

for example:
connection.Execute("INSERT IGNORE INTO OrderDetails (id) values (@id)",new {id= "333"});

Prior versions of this library supported ReadAsync called with these generic parameters:

ReadAsync<string, TimeSpan?, TimeSpan?, string, bool>(sql)

But with newer versions this throws:

Norm.NormMultipleMappingsException: Multiple mappings requires types of same category:
    Classes with classes, records with records, value tuples with value tuple and simple types with simple types.
    For example pappings `Read<Class, int>` or `Read<int, Class>` are not permitted.

Would support for mapping for insert statements be something you're willing to look at?

If I do var record in conn.ReadAsync<dynamic>("select 1 as test_test) the column name test_test will be converted to expando key testtest, I think due to this. Is there a reason to remove the underscores?

Is there a way to expand the object mapper with custom types?
I'm currently using an external object that use DateTimeOffset on one of the properties, which is not among the basic supported types. I can't seem to find a way to work around that without mapping the object manually. For large objects that's a a bit unfortunate.

The syntax for doing a join query with multiple tables is interesting, but it seems to only work with INNER joins. Let's consider we have an Assets and a Vehicles table, where there is an optional correspondence of 1-1. Here's what the query would look like (excluding grouping code for simplification).

var tuple = await connection.Cast()
    .ReadAsync<Asset, Vehicle?>(
        """
        select a.*, v.*
        from assets a
        left join vehicles v on a.id = v.id
        """
    )
    .ToListAsync();

If I change the query to an INNER JOIN it works and I kind of expected the LEFT JOIN to work also by setting a nullable in the tuple, but it doesn't.

If it's not a lot a work, I think this could be an interesting fix.

Would like to see benchmark which fulfils the claim.

I pulled your NormPgIdentity code, set the database up, did the migrations, then ran the program. Everything worked as published. I was very happy because I am no fan of EF. I started a new project, set it to botnet Core 5 and c# 9. Pulled the packages (latest ones), Norm.net/3.3.1, Npgsql/6.0.0=preiview, System.Linq.Async/5.0.0 and AspNetCore.Identity.UI/45.0.8.

I had to change UserStore and RoleStore to get the IDE to stop complaining. There were a couple other small items that I fixed. Ran the program. I was able to register a user. The data ended up correct in the database. All was good. However when I go to login I get an exception "InvalidCastException: Can't cast database type bigint to IdentityUser`1". It happens in the FindAsync function. This is what I changed it to:

private async Task<IdentityUser> FindAsync(CancellationToken cancellationToken, long? userId = null, string name = null, string email = null) =>
await _connection.WithCancellationToken(cancellationToken).ReadAsync<IdentityUser>($@"

            select
                {GetUserSelectRecord()}

            from
                ""user"" u

            where
                ( @id is null or u.id = @id ) and 
                ( @name is null or u.normalized_user_name = @name ) and 
                ( @email is null or u.normalized_email = @email )
        
        ", ("id", userId, DbType.Int64), ("name", name, DbType.String), ("email", email, DbType.String))
            .FirstOrDefaultAsync(cancellationToken);

Did I not correct the above function correctly?

Thanks,
Bob

Hi there!

Are you planning to add support for custom types? like the SqlMapper.TypeHandler in Dapper?

thanks!

I've got a situation with a query that returns an hstore type field. According to the driver docs, this type defaults to a Dictionary<string, string>.

Here's the simplified query; removed unnecessary clutter for clarity

select 
    name,
    tags::hstore
from planet_osm_roads
limit 1;

For this use case, I created a model class, which looks like this

internal sealed class RoadSegmentModel
{
    public string? Name { get; set; }
    public Dictionary<string, string>? Tags { get; set; }
}

The type mapping I think it's accurate, because if I change it to a string, I get the following exception, which would be expected

System.InvalidCastException: Unable to cast object of type 'System.Collections.Generic.Dictionary`2[System.String,System.String]' to type 'System.String'.

So... the code to execute the query is pretty much straightforward

var result = await connection.ReadAsync<RoadSegmentModel>( sql )
    .ToArrayAsync();

However, when executing this, I'm presented with the following exception

System.NotImplementedException: TypeCode Object not implemented
   at Norm.Mapper.NormExtensions.CreateDelegate[T](PropertyInfo property, Boolean nullable)
   at Norm.Mapper.NormExtensions.MapInstance[T](ReadOnlyMemory`1 tuple, T& instance, MapDescriptor& descriptor, ValueTuple`7[]& delegates)
   at Norm.Mapper.NormExtensions.Map[T](IAsyncEnumerable`1 tuples, Type type1)+MoveNext()
   at Norm.Mapper.NormExtensions.Map[T](IAsyncEnumerable`1 tuples, Type type1)+MoveNext()
   at Norm.Mapper.NormExtensions.Map[T](IAsyncEnumerable`1 tuples, Type type1)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()

Am I missing something here, maybe?

Hey, I'm trying to map a result of json_agg combined with normal columns.
This is the query:

    select id, foo, json_agg(
            json_build_object(
                    'Name1', t.name1,
                    'Name2', t.name2
                )
        ) from (
                      values
                          (1, 'foo1', 'testname1', 'x'),
                          (2, 'foo2', 'testname2', 'y'),
                          (2, 'foo2', 'testfoo3', 'yy'),
                          (3, 'foo3', 'testname3', 'z')
                  ) t(id, foo, name1, name2)
    GROUP BY id, foo;

And I'm trying to map it with the following code:

connection.ReadAsync<FirstPart, JsonPart[]>(...)

public class FirstPart
{
    public required int Id { get; init; }
    public required string Foo { get; init; }
}

public class JsonPart
{
    public required string Name1 { get; init; }
    public required string Name2 { get; init; }
}

The following exception is thrown:

System.InvalidCastException: Can't cast database type integer to FirstPart
   at Npgsql.Internal.TypeHandling.NpgsqlTypeHandler.ReadCustom[TAny](NpgsqlReadBuffer buf, Int32 len, Boolean async, FieldDescription fieldDescription)
   at Npgsql.NpgsqlDataReader.GetFieldValue[T](Int32 ordinal)
   at Npgsql.NpgsqlDataReader.GetFieldValueAsync[T](Int32 ordinal, CancellationToken cancellationToken)
   at Norm.Norm.GetFieldValueAsync[T](DbDataReader reader, Int32 ordinal, Type type)
   at Norm.Norm.<>c__DisplayClass108_0`2.<<ReadAsync>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Norm.Norm.ReadCallbackAsync[T](String command, Func`2 readerAction)+MoveNext()

It's working if I replace FirstPart with value types: ReadAsync<int, string, JsonPart[]>. Maybe it's the proper way of doing it and I'm just doing weird stuff 😄