UskokDB 2.1.1

UskokDB

A simple C# ORM which adds extension methods on IDbConnection and DbConnection classes

Quering

Lets supose we have a model specified like:

class Person
{
    public string Name { get; set; }
    public string LastName { get; set; }
}

//Getting a connection instance from some factory
IDbConnection connection = SomeConnectionFactory.CreateConnection();

Sync quering

List<dynamic> people = connection.Query("Select * From people Where name=@Name", new { 
    Name = "Vuk" 
})
List<Person> people = connection.Query<Person>("Select * From people Where name=@Name", new { 
    Name = "Vuk" 
})
dynamic person = connection.QuerySingle("Select * From people Where name=@Name", new { 
    Name = "Vuk" 
})
Person person = connection.QuerySingle<Person>("Select * From people Where name=@Name", new { 
    Name = "Vuk" 
})

Async Quering

List<dynamic> people = await connection.QueryAsync("Select * From people Where name=@Name", new { 
    Name = "Vuk" 
})
List<Person> people = await connection.QueryAsync<Person>("Select * From people Where name=@Name", new { 
    Name = "Vuk" 
})
dynamic person = await connection.QuerySingleAsync("Select * From people Where name=@Name", new { 
    Name = "Vuk" 
})
Person person = await connection.QuerySingleAsync<Person>("Select * From people Where name=@Name", new { 
    Name = "Vuk" 
})

IParamterConverter

The ParameterHandler class has a static dictionary Dictionary<Type, IParamterConverter> ParamterConverters which is used as a map to create db values from custom types the prime example of this is Guid demostrated here

[typeof(Guid)] = new DefaultParamterConverter<Guid, string>((guid) => guid.ToString(), Guid.Parse, Guid.Empty.ToString().Length)

The DefaultParamterConverter takes in a function of when writing to a database and a function when reading it along side with the int? maxLength and string? typeName, maxLength is used to determine the max length in case the writen type is string in which case this is and it is Guid.Empty.ToString().Length and typeName is used in the extension library UskokDB.MySql to know what type should be written in case of a for example DateTime this parameter would be DATETIME.

Note! Primtive types cannot be changed (int, uint, char, bool, short, ushort, enum, string, double, float, decimal, etc...)

IParamterConverter is used for the type Guid so that the model can be represented like this

class Person 
{
    public Guid Id;
    public string Name;
    public string LastName;
}

This can be just any type so lets create an example

//This is a kind of dumb example but shows the way it used
const int MaxNameLength = 20;
class NameClass
{
    public string Value; 
}
class Person 
{
    public Guid Id;
    public NameClass Name;
    public NameClass LastName;
}
ParameterHandler.ParamterConverters[typeof(NameClass)] = new DefaultParamterConverter<NameClass, string>(nameClass => nameClass.Value, (str) => new NameClass { Value = str }, MaxNameLength)

Column Attribute

You can use the column attribute in order to specify a name for a certain property and here is an example of this

class Person {
    [Column("name")]
    public string FullName {get; set;}
}

Person p = connection.QuerySingle<Person>("Select * From people where name='Somename'")

As you can see the column name in the table is name but we can still name the property as we wish as long as we specify the actuall name of the column with the attribute

NotMapped Attribute

You can ignore a specific property with this attribute

class Person {
    [NotMapped]
    public string FullName {get; set;}
    
    public int Age {get; set;}
}

Json

You can configure the library to use json for unkown structs and classes this is however 
bypassed if a speicifc way of converting is specified in the convert dictionary

//This sets the usage
ParameterHandler.UseJsonForUnknownClassesAndStructs = true;

//And here is an example with Newtonsoft.Json but you can use any library as you wish
ParameterHandler.JsonWriter = (object? someInstance) => 
    someInstance == null? null : JsonConvert.SerializeObject(someInstance);
    //If you return null, null value will be stored in the column
    
ParameterHandler.JsonReader = (string? jsonString, Type columnType) =>
    jsonString == null? null : JsonConvert.DeserializeObject(jsonString, columnType);