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The following example demonstrates how to create and use an abstract data accessor class. All abstract methods of the class are generated at run-time depending on each method declaration. Every part of the method declaration is important. Method's return value specifies one of the Execute methods in the following way:

Return TypeExecute Method
IDataReader interfaceExecuteReader
Subclass of DataSet ExecuteDataSet
Subclass of DataTableExecuteDataTable
Class implementing the IList interfaceExecuteList or ExecuteScalarList
Class implementing the IDictionary interfaceExecuteDictionary or ExecuteScalarDictionary
voidExecuteNonQuery
string, byte[] or value typeExecuteScalar
In any other caseExecuteObject

Method name explicitly defines action name which is converted to stored procedure name.
Type, sequential order, and name of the method parameters is mapped to the command parameters. Exceptions from this rule are:

  • a parameter of DbManager type. In this case generator uses provided DbManager to call the command.
  • parameters decorated with attribute FormatAttribute.

AbstractAccessor.cs

using System;
using System.Collections.Generic;

using NUnit.Framework;

using BLToolkit.Data; using BLToolkit.DataAccess;

namespace HowTo.DataAccess { [TestFixture] public class AbstractAccessor { public abstract class PersonAccessor : DataAccessor<Person> { public abstract Person SelectByName(Person person); public abstract Person SelectByName(string firstName, string lastName);

public abstract int Insert (Person person);

[SqlQuery("SELECT Top {0} * FROM Person ORDER BY PersonID")] [Index("ID")] public abstract Dictionary<int,Person> SelectTop([Format(0)] int top);

private SprocQuery<Person> _query; public SprocQuery<Person> Query { get { if (_query == null) _query = new SprocQuery<Person>(DbManager); return _query; } } }

[Test] public void Test() { using (DbManager db = new DbManager()) { PersonAccessor pa = DataAccessor.CreateInstance<PersonAccessor>(db);

pa.BeginTransaction();

// Insert and get id. // Person person = new Person();

person.FirstName = "Crazy"; person.LastName = "Frog"; person.Gender = Gender.Unknown;

int id = pa.Insert(person);

// SelectByName. // person = pa.SelectByName("Crazy", "Frog");

Assert.IsNotNull(person);

// Select top. // Dictionary<int,Person> dic = pa.SelectTop(10);

Assert.IsTrue(dic.Count <= 10);

// Delete. // pa.Query.Delete(person);

pa.CommitTransaction(); } } } }

Person.cs

using System;

using BLToolkit.DataAccess; using BLToolkit.Mapping;

namespace HowTo.DataAccess { public class Person { [MapField("PersonID"), PrimaryKey, NonUpdatable] public int ID;

public string LastName; public string FirstName; public string MiddleName; public Gender Gender; } }

Gender.cs

using System;

using BLToolkit.Mapping;

namespace HowTo.DataAccess { public enum Gender { [MapValue("F")] Female, [MapValue("M")] Male, [MapValue("U")] Unknown, [MapValue("O")] Other } }

App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <connectionStrings>
        <add
            name             = "DemoConnection"
            connectionString = "Server=.;Database=BLToolkitData;Integrated Security=SSPI"
            providerName     = "System.Data.SqlClient" />
    </connectionStrings>
</configuration>
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