generic method and anonymous types

Question

Would it be possible to create code like this:

private static string GetInsertString<TDto>()
{
    var type = typeof(TDto);
    var properties = type.GetProperties().Where(Where);
    var tableName = type.Name;

    return string.Format("INSERT INTO {0} ({1}) VALUES ({2});", 
    tableName, 
    string.Join(",", properties.Select(x => x.Name).ToArray()),
    string.Join(",", properties.Select(x => string.Format("@{0}", x.Name.ToLower())).ToArray()));
}

that works with anonymous types like this:

var point = new { X = 13, Y = 7 };

PS:

Output would be:

INSERT INTO Anonymous (X, Y) values (13, 7)

of course you may want to provide the table name.

Answer 1

You won't be able to specify the type parameter with an anonymous type, but if you pass it an object as a parameter, you can use type inference to get a hold of the type:

private static string GetInsertString<TDto>(TDto dto)
{
    var type = typeof(TDto);
    var propertyNames = type.GetProperties().Where(Where).Select(x => x.Name);

    return string.Format("INSERT INTO {0} ({1}) VALUES ({2});",
        type.Name,
        string.Join(",", propertyNames),
        string.Join(",", propertyNames.Select(x => string.Format("@{0}", x.ToLower())));
}

Then call the method: var insertString = GetInsertString(new { X = 13, Y = 7 });