隆重推荐：DAC 4.0 全新发布

DAC 4.0 是一个全新的版本，几乎全部重写了以前的代码，设计的结构也简化很多，基于.net4,使用lambda表达式代替反射，去除大量过时的功能（如DataTable和DataSet的相关功能等），去除自定义表达式部分，通过解析lambda表达式实现自定义条件查询。使用.net自带Configuration功能，只要web.config或app.config，不需要额外的配置文件，方便配置使用；去除xml mapping方式，支持DLinq属性。支持多种数据库（已测试sql server, mysql, sqlite及oracle), 支持mono(ubuntu 11.10 + mono 2.10.5 + mysql 5.1.58测试通过)。

代码示例：

初启化,通过配置文件或connection string构造DataContext:

var dc = new DataContext("RaisingStudio.Data.TestProject.Properties.Settings.DefaultConnectionString");
或
var dc = new DataContext("server=localhost;User Id=root;password=root;database=test;");

lambda表达式查询：

var q = this.dc.Query<Item>(i => i.Name == "test" && i.Status == "ok");

或linq查询：

var q = from s in dc.GetQuery<Supplier>() 
    where s.SuppId > 0 && s.Name == "for Test3" 
    select s;

增删改：

this.dc.Insert<Product>(new Product
{
    ProductId = Guid.NewGuid().ToString(),
        CategoryId = categoryId,
        Name = "for Test4"                
});


this.dc.Delete<Supplier>(suppId);

this.dc.Update<Product>(product);

this.dc.Save<Category>(category);

通过主键获取单个实例：

var product = this.dc.GetEntity<Product>(productId);

支持排序和分页：

List<Item> items = this.dc.Query<Item>(ExpressionExtension.Empty<Item>().Take(3)).ToList();
var q = (from i in this.dc.GetQuery<Item>()
                    select i).Skip(1).Take(2);
int count = this.dc.Query<Item>(ExpressionExtension.Empty<Item>().Skip(1)).Count();

部分列：

this.dc.Save<Item>(item, new string[] { "UnitCost" });

this.dc.Insert<Item>(item, new Expression<Func<Item, object>>[] 
{ 
        i => i.ItemId,
        i => i.Name,
        i => i.ListPrice,
        i => i.ProductId,
        i => i.Status
});

无实例类查询：

Command command = new Command("SELECT * FROM Product WHERE CategoryId = @p1");
command.AddParameter("@p1", categoryId);
var q = this.dc.Query(command);
int count = 0;
foreach (dynamic p in q)
{
     Assert.IsNotNull(p);
     Assert.AreEqual(p.CategoryId, categoryId);
     count++;
}

事务处理：

            this.dc.BeginTransaction();
            try
            {
                int result = this.dc.Insert<Supplier>(new Supplier
                {
                    Name = "s for Test6",
                    Status = "done",
                    City = "dalian"
                });

                int suppId = Convert.ToInt32(this.dc.GetIdentity<Supplier>());
                result = this.dc.Delete<Supplier>(suppId);

                Category category = new Category
                {
                    CategoryId = Guid.NewGuid().ToString(),
                    Name = "c for Test6",
                    Descn = "d for Test6"
                };                
                Product product = new Product
                {
                    ProductId = Guid.NewGuid().ToString(),
                    Name = "p for Test6",
                    Descn = "d for Test6",
                    CategoryId = category.CategoryId
                };
                result = this.dc.Insert<Category>(category);
                result = this.dc.Insert<Product>(product);

                this.dc.CommitTransaction();
            }
            catch (Exception ex)
            {
                this.dc.RollbackTransaction();
                throw ex;
            }

配置文件示例：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <sectionGroup name="raisingstudio.data" type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <section name="CommandConverter.Settings" type="RaisingStudio.Data.CommandConverterSettings, RaisingStudio.Data" />
      <section name="CommandBuilder.Settings" type="RaisingStudio.Data.CommandBuilderSettings, RaisingStudio.Data" />
    </sectionGroup>
  </configSections>
  <system.data>
    <DbProviderFactories>
      <add name="System.Data.SQLite" invariant="System.Data.SQLite" description="ADO.NET Data Provider for SQLite" type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite" />
      <add name="Oracle.DataAccess" invariant="Oracle.DataAccess" description="Oracle.DataAccess" type="Oracle.DataAccess.Client.OracleClientFactory, Oracle.DataAccess" />      
    </DbProviderFactories>
  </system.data>
  <raisingstudio.data>
    <CommandConverter.Settings>
      <add name="System.Data.OracleClient" providerName="System.Data.OracleClient" usePositionalParameters="false" parameterPrefix=":" useParameterPrefixInParameter="false" useParameterPrefixInSql="true" />
      <add name="Oracle.DataAccess" providerName="Oracle.DataAccess" usePositionalParameters="false" parameterPrefix=":" useParameterPrefixInParameter="false" useParameterPrefixInSql="true" />
    </CommandConverter.Settings>
    <CommandBuilder.Settings>
      <add name="MySql.Data.MySqlClient" providerName="MySql.Data.MySqlClient"  pagingMethod="LIMIT" identityMethod="LAST_INSERT_ID" useBrackets="false" />
      <add name="System.Data.SQLite" providerName="System.Data.SQLite"  pagingMethod="LIMIT" identityMethod="LAST_INSERT_ROWID"/>
      <add name="System.Data.OracleClient" providerName="System.Data.OracleClient" pagingMethod="ROWNUM" identityMethod="CURRVAL" />
      <add name="Oracle.DataAccess" providerName="Oracle.DataAccess" pagingMethod="ROWNUM" identityMethod="CURRVAL"  useBrackets="false" />
    </CommandBuilder.Settings>
  </raisingstudio.data>
  <connectionStrings>
    <add name="RaisingStudio.Data.TestProject.Properties.Settings.DefaultConnectionString"
      connectionString="Data Source=localhost;Initial Catalog=test;Integrated Security=True"
      providerName="System.Data.SqlClient" />
    <add name="RaisingStudio.Data.TestProject.Properties.Settings.MySqlConnectionString"
      connectionString="server=localhost;User Id=root;password=root;Persist Security Info=True;database=test"
      providerName="MySql.Data.MySqlClient" />
    <add name="RaisingStudio.Data.TestProject.Properties.Settings.SqliteConnectionString"
      connectionString="Data Source=test.db" providerName="System.Data.SQLite" />
    <add name="RaisingStudio.Data.TestProject.Properties.Settings.OracleConnectionString"
      connectionString="Data Source= (DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = zhongzf-PC)(PORT = 1522))  (CONNECT_DATA = (SERVER = DEDICATED)  (SERVICE_NAME = XE) ) );User Id=demo;Password=demo;"
      providerName="Oracle.DataAccess" />
  </connectionStrings>
</configuration>

下载地址：http://dac.codeplex.com/