private static ConnectionStringElement GetConfiguration(string name)
{
ConnectionManagerConfigurationSection section =
ConnectionManagerConfigurationSection.GetConfig();
ConnectionStringConfigurationElement configElement = section.ConnectionStrings[name];
ConnectionStringElement element = null;
// 本地配置文件的连接串采用优先级高于Meta库中的
if (configElement != null)
{
element = new ConnectionStringElement();
element.ConnectionString = configElement.ConnectionString;
element.ProviderName = configElement.ProviderName;
element.EventArgsType = configElement.EventArgs.Type;
element.Name = configElement.Name;
element.CommandTimeout = configElement.CommandTimeout;
}
else
{
// 备选通道是从Meta库获取
MetaConnectionStringConfigurationElement metaElement = section.MetaConnectionString;
if (metaElement != null)
{
element = metaElement.GetConnectionStringElement(name);
}
}
return(element);
}
/// <summary>
/// 数据库联接是否定义
/// </summary>
/// <param name="name"></param>
public static bool ConnectionNameIsConfiged(string name)
{
ExceptionHelper.CheckStringIsNullOrEmpty(name, "name");
ConnectionStringElement settings = GetConfiguration(name);
return(settings != null);
}
protected virtual void Parse()
{
this.settings = new ConnectionStringElement();
ParseOriginalSettings();
ParseBuilders();
ParseEventArgs();
isParsed = true;
}
/// <summary>
/// 获取指定连接的DbProviderFactory对象(Added by Shen Zheng
/// </summary>
/// <param name="name"></param>
/// <returns></returns>
internal static DbProviderFactory GetDbProviderFactory(string name)
{
ExceptionHelper.CheckStringIsNullOrEmpty(name, "name");
ConnectionStringElement elem = GetConfiguration(name);
ExceptionHelper.FalseThrow <ConfigurationException>(elem != null, Resource.CanNotFindConnectionName, name);
return(DbProviderFactories.GetFactory(elem.ProviderName));
}
/// <summary>
/// 根据数据库逻辑名称获得连接实例
/// </summary>
/// <param name="name">数据库逻辑名称</param>
/// <returns>数据库连接实例</returns>
internal static DbConnection GetConnection(string name)
{
ExceptionHelper.CheckStringIsNullOrEmpty(name, "name");
ConnectionStringElement settings = GetConfiguration(name);
ExceptionHelper.FalseThrow <ConfigurationException>(settings != null, Resource.CanNotFindConnectionName, name);
DbConnection dbConnection = DbProviderFactories.GetFactory(settings.ProviderName).CreateConnection();
dbConnection.ConnectionString = settings.ConnectionString;
return(dbConnection);
}
protected override void ParseBuilders()
{
if (isMetaConnectionParsed)
{
return;
}
isMetaConnectionParsed = true;
// 配置文件的解析好像成问题，保险的办法就是在这里try一下重新解析
if (settings == null)
{
settings = new ConnectionStringElement();
settings.Name = (string)this["name"];
settings.ConnectionString = (string)this["connectionString"];
settings.ProviderName = (string)this["providerName"];
}
ParseSettingBuildersByPrefix(MetaSectionPrefix, ref settings);
TranslateMetaConnections();
}
private void TranslateMetaConnections()
{
DataTable result = LoadMetaConnections();
if (result == null)
{
return;
}
metaConnectionSettings = new Dictionary <string, ConnectionStringElement>();
foreach (DataRow row in result.Rows)
{
ConnectionStringElement setting = new ConnectionStringElement();
setting.Name = row["NAME"] as string;
setting.ConnectionString = row["CONNECTION_STRING"] as string;
setting.ProviderName = row["PROVIDER_NAME"] as string;
setting.EventArgsType = row["EVENT_ARGUMENT_TYPE"] as string;
ParseSettingBuildersByPrefix(ItemSectionPrefix, ref setting);
metaConnectionSettings.Add(setting.Name, setting);
}
}
private void ParseSettingBuildersByPrefix(string prefix, ref ConnectionStringElement setting)
{
if ((Builders != null) && (Builders.Count > 0))
{
foreach (BuilderConfigurationElement elementBuilder in Builders)
{
if ((elementBuilder.Name.StartsWith(prefix)) || (elementBuilder.Name.StartsWith(BothSectionPrefix)))
{
ConnectionStringBuilderBase builder = (ConnectionStringBuilderBase)TypeCreator.CreateInstance(elementBuilder.Type);
switch (elementBuilder.AttributeName)
{
case "connectionString":
setting.ConnectionString = builder.BuildUp(setting.ConnectionString); break;
case "name":
setting.Name = builder.BuildUp(setting.Name); break;
case "providerName":
setting.ProviderName = builder.BuildUp(setting.ProviderName); break;
}
}
}
}
}