/// <summary>
/// 构造函数
/// </summary>
/// <param name="dbType">数据库类型</param>
/// <param name="conStr">连接名或连接字符串</param>
public DbHelper(DatabaseType dbType, string conStr)
{
_dbType = dbType;
_conStr = DbProviderFactoryHelper.GetConStr(conStr);
}
