Monthly Archives: December 2014

MicroLite 6.0 – Specifying the DbType

In MicroLite 6.0, we have exposed the ability to control the mapping between a .NET Type and the Database Type (DbType).

If not explicitly configured, the types will be mapped using the default mappings – you can see the default mappings here

If you use the Attribute based mapping and want to specify the DbType for a specific property, you can set it in the ColumnAttribute applied to that property:

[Column("DoB", DbType.DateTime2)]
public DateTime DateOfBirth { get; set; }

If you use convention based mapping and want to specify the DbType for a specific property, you can define that in your own convention:

        new ConventionMappingSettings
        {
            ResolveDbType = (PropertyInfo propertyInfo) =>
            {
                if (propertyInfo.PropertyType == typeof(DateTime) && propertyInfo.ReflectedType == typeof(Customer))
                {
                     return DbType.DateTime2;
                }

                // Use the default
                return TypeConverter.ResolveDbType(propertyInfo.PropertyType);
            }

If you always want to use a specific DbType for a .NET Type, you can set it via the TypeConverter class:

// Always use DbType.DateTime2 instead of DbType.DateTime for System.DateTime
TypeConverter.RegisterTypeMapping(typeof(DateTime), DbType.DateTime2);
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MicroLite 6.0 – Dynamic Connection Strings

Prior to MicroLite 6.0, in order to create a session factory you had to specify the connection name as defined in the connection strings section of your application configuration. This is generally a good idea as the connection string is a configuration value which should not be baked into the code as you would need a different value if you have separate Dev/Test/Production environments.

We did have a request from a MicroLite user to be able to specify the connection string at runtime as there is a requirement for that in his application so we have added functionality for doing just that.

The ForConnection methods now have an additional overload:

ForMsSql2005Connection(string connectionName, string connectionString, string providerName)

The reason that the new overload needs a connection name is to still allow support for the MVC and WebApi extensions which are dependent on a named connection to resolve the correct session factory.

The provider name needs to be the same as you would set in the connection string in the application config, this is used by MicroLite to resolve the correct DbProviderFactory.

This gives you two ways to configure a connection in MicroLite 6.0:

Option 1 (the recommended approach for most use cases)

Define the connection string in the application configuration

<connectionStrings>
    <add name="NorthwindDB"
         connectionString="Data Source=localhost;Initial Catalog=Northwind;Persist Security Info=False;Integrated Security=SSPI;"
         providerName="System.Data.SqlClient" />
</connectionStrings>
// Create the session factory for the named connection
var sessionFactory = Configure
        .Fluently()
        .ForMsSql2005Connection("NorthwindDB")
        .CreateSessionFactory();

Option 2 (if you really really need to)

// Create the session factory with the specified name, connection string and provider name
var sessionFactory = Configure
        .Fluently()
        .ForMsSql2005Connection(
               "NorthwindDB",
               "Data Source=localhost;Initial Catalog=Northwind;Persist Security Info=False;Integrated Security=SSPI;",
               "System.Data.SqlClient")
        .CreateSessionFactory();

Upgrading to MicroLite 6.0

There are a few changes in MicroLite 6.0 and some of the extensions which you need to be aware of when updating from a previous version.

The .NET 4.5 build now contains an Async version of the session api (IAsyncSession and IAsyncReadOnlySession). If you are using a .NET 4.5 app, I suggest you update to make full use of the async version. The MVC and WebApi extensions already exclusively make use of it (see further below for more details).

Here’s the .NET 4.5 async version of each session method:

.NET 4.0 API .NET 4.5 API
Read API
Session.Fetch(SqlQuery) await Session.FetchAsync(SqlQuery)
Session.Paged(SqlQuery) await Session.PagedAsync(SqlQuery)
Session.Single(obj) await Session.SingleAsync(obj)
Session.Single(SqlQuery) await Session.SingleAsync(SqlQuery)
Write API
Session.Delete(obj) await Session.DeleteAsync(obj)
Session.Insert(obj) await Session.InsertAsync(obj)
Session.Update(obj) await Session.UpdateAsync(obj)
Session.Advanced.Delete(Type, obj) await Session.Advanced.DeleteAsync(Type, obj)
Session.Advanced.Execute(SqlQuery) await Session.Advanced.ExecuteAsync(SqlQuery)
Session.Advanced.ExecuteScalar(SqlQuery) await Session.Advanced.ExecuteScalarAsync(SqlQuery)
Session.Advanced.Update(ObjectDelta) await Session.Advanced.UpdateAsync(ObjectDelta)

Attribute Mapping

If you use the attribute based mapping, the attributes are now in the MicroLite.Mapping.Attributes namespace rather than MicroLite.Mapping.

DbEncryptedString

The DbEncryptedString class and associated classes has moved to the new MicroLite.Extensions.Cryptography project

SQL Builder

The Delete and Update Builder WhereEquals method has been replaced with Where().IsEqualTo() to align it with the Select Builder

MicroLite.Extensions.Mvc

Method signature needs to change from:

public ActionResult MethodName(args)

to

public async Task<ActionResult> MethodName(args)

MicroLite.Extensions.WebApi

Method signature needs to change from:

public HttpResponseMessage Get(int id)

to

public Task<HttpResponseMessage> Get(int id)

example:

public Task<HttpResponseMessage> Get(int id)
{
    return this.GetEntityResponseAsync(id);
}