/// <summary>
/// 创建一个连接
/// <remarks>
/// the connection retrieve process is as the following procedure:
/// <list type="bullet">
/// <item>if no transaction exists, this method create and return a new DbConnection instance</item>
/// <item>if transaction exists, this method should return a cached DbConnection instance</item>
/// </list>
/// <param name="isConnectionCreator">输出参数，返回连接是否创建成功</param>
/// <param name="name">数据库连接名称</param>
/// </remarks>
/// </summary>
private DbConnection CreateConnection(string name, out bool isConnectionCreator)
{
DbConnection connection;
isConnectionCreator = false;
// non-transactional operation
GraphWithoutTransaction connections = GraphWithoutTx;
if (Transaction.Current == null)
{
connection = GetConnectionWithoutTx(name);
}
else
{
connection = OnGetConnectionWithTransaction(Transaction.Current);
}
if ((connection != null) && (connection.State != ConnectionState.Open))
{
if (string.IsNullOrEmpty(connection.ConnectionString))
{
connection.ConnectionString = DbConnectionManager.GetConnectionString(name);
}
connection.Open();
WriteTraceInfo(connection.DataSource + "." + connection.Database
+ "[" + DateTime.Now.ToString("yyyyMMdd HH:mm:ss.fff") + "]", " Open Connection ");
}
return(connection);
}
/// <summary>
/// 获取一个DbContext对象
/// </summary>
/// <param name="name">连接名称</param>
/// <param name="autoClose">是否自动关闭</param>
/// <returns>DbContext对象</returns>
public static DbContext GetContext(string name, bool autoClose)
{
//得到映射后连接名称
name = DbConnectionMappingContext.GetMappedConnectionName(name);
DbProviderFactory factory = DbConnectionManager.GetDbProviderFactory(name);
DbConnectionStringBuilder csb = factory.CreateConnectionStringBuilder();
csb.ConnectionString = DbConnectionManager.GetConnectionString(name);
bool enlist = true;
if (csb.ContainsKey("enlist"))
{
enlist = (bool)csb["enlist"];
}
DbContext result = null;
if (enlist)
{
result = new AutoEnlistDbContext(name, autoClose);
}
else
{
result = new NotEnlistDbContext(name, autoClose);
}
result.autoClose = autoClose;
return(result);
}