/// <summary>
/// 创建一个 db provider.
/// </summary>
/// <param name="assemblyName">程序集名</param>
/// <param name="className">类名</param>
/// <param name="connectionString">connectionString</param>
/// <returns>Db provider.</returns>
public static DbProvider CreateDbProvider(string assemblyName, string className, string connectionString)
{
Guard.IsNotNullOrEmpty(connectionString, "connectionString");
//首先判断ConnectionString是否不是Access驱动
if (connectionString.IndexOf("microsoft.jet.oledb", StringComparison.OrdinalIgnoreCase) > -1 || connectionString.IndexOf(".db3", StringComparison.OrdinalIgnoreCase) > -1)
{
Guard.Check(connectionString.IndexOf("data source", StringComparison.OrdinalIgnoreCase) > -1, "ConnectionString的格式有错误，请检查");
string mdbPath = connectionString.Substring(connectionString.IndexOf("data source", StringComparison.OrdinalIgnoreCase) + "data source".Length + 1).TrimStart(' ', '=');
if (mdbPath.ToLower().StartsWith("|datadirectory|"))
{
mdbPath = AppDomain.CurrentDomain.BaseDirectory.TrimEnd('\\') + "\\App_Data" + mdbPath.Substring("|datadirectory|".Length);
}
else if (connectionString.StartsWith("./") || connectionString.EndsWith(".\\"))
{
connectionString = connectionString.Replace("/", "\\").Replace(".\\", AppDomain.CurrentDomain.BaseDirectory.TrimEnd('\\') + "\\");
}
connectionString = connectionString.Substring(0, connectionString.ToLower().IndexOf("data source")) + "Data Source=" + mdbPath;
}
//如果是~则表示当前目录
if (connectionString.Contains("~/") || connectionString.Contains("~\\"))
{
connectionString = connectionString.Replace("/", "\\").Replace("~\\", AppDomain.CurrentDomain.BaseDirectory.TrimEnd('\\') + "\\");
}
//默认使用sqlserver db provider
if (string.IsNullOrEmpty(className))
{
className = typeof(SqlServer.SqlServerProvider).ToString();
}
else if (string.Compare(className, "System.Data.SqlClient", true) == 0 || string.Compare(className, "Liger.Data.SqlServer", true) == 0)
{
className = typeof(SqlServer.SqlServerProvider).ToString();
}
else if (string.Compare(className, "Liger.Data.SqlServer9", true) == 0 || className.IndexOf("SqlServer9", StringComparison.OrdinalIgnoreCase) >= 0 || className.IndexOf("sqlserver2005", StringComparison.OrdinalIgnoreCase) >= 0 || className.IndexOf("sql2005", StringComparison.OrdinalIgnoreCase) >= 0)
{
className = typeof(SqlServer9.SqlServer9Provider).ToString();
}
else if (className.IndexOf("oracle", StringComparison.OrdinalIgnoreCase) >= 0)
{
className = typeof(Oracle.OracleProvider).ToString();
}
else if (className.IndexOf("access", StringComparison.OrdinalIgnoreCase) >= 0)
{
className = typeof(MsAccess.MsAccessProvider).ToString();
}
//待实现
else if (className.IndexOf("mysql", StringComparison.OrdinalIgnoreCase) >= 0)
{
className = "Liger.Data.MySql.MySqlProvider";
assemblyName = "Liger.Data.MySql";
}
//待实现
else if (className.IndexOf("sqlite", StringComparison.OrdinalIgnoreCase) >= 0)
{
className = "Liger.Data.Sqlite.SqliteProvider";
assemblyName = "Liger.Data.Sqlite";
}
string cacheKey = string.Concat(assemblyName, className, connectionString);
if (providerCache.ContainsKey(cacheKey))
{
return(providerCache[cacheKey]);
}
else
{
System.Reflection.Assembly ass;
if (assemblyName == null)
{
ass = typeof(DbProvider).Assembly;
}
else
{
ass = System.Reflection.Assembly.Load(assemblyName);
}
DbProvider retProvider = ass.CreateInstance(className, false, System.Reflection.BindingFlags.Default, null, new object[] { connectionString }, null, null) as DbProvider;
providerCache.Add(cacheKey, retProvider);
return(retProvider);
}
}
public ExpressionTranslater(DbProvider dbProvider)
: this(dbProvider, null)
{
}
public ExpressionTranslater(DbProvider dbProvider, EntityQueryExpression exp)
{
this.DbProvider = dbProvider;
this.Params = new List <QueryParameter>();
this.Expression = exp;
}
/// <summary>
/// 翻译成SQL,并生成相应的参数
/// </summary>
public void Translate()
{
DbProvider.PrepareTranslater(this);
this.CommandText = TranslateEntityQuery(this.Expression);
DbProvider.AdjustTranslater(this);
}