数据库的访问类小知识点

//获取连接字符串，在未引用System.Configuration时可以手动拼写引用
//private static string _connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["StockDB"].ConnectionString;
private static string _connectionString = ConfigurationManager.ConnectionStrings["StockDB"].ConnectionString;
SqlConnection conn = null;
SqlCommand cmd = null;
public AllocationBusiness() 
{
   conn = new SqlConnection(_connectionString);
   cmd = conn.CreateCommand();
}

//通用数据库访问类
//strconn为获取的连接字符串
Utilities.DbUtility.DbAccess DBdataStatistics = new Utilities.DbUtility.DbAccess(strconn, Utilities.DbUtility.DbProviderType.SqlServer);

在EF模板生成的数据库连接文件中，也可以用这种方式获取：如生成类名为：StockDBEntities

using (StockDBEntities db2 = new StockDBEntities())
{
     db2.Database.CommandTimeout = 200;//响应时间，可根据情况不写
     //因连接配置已经模板生成，此处获取连接字符串的方式就是：db2.Database.Connection.ConnectionString
     Utilities.DbUtility.DbAccess db = new Utilities.DbUtility.DbAccess(db2.Database.Connection.ConnectionString, Utilities.DbUtility.DbProviderType.SqlServer);
}

 本地操作日志及错误日志的写法：（要添加引用Utilities.dll）

        /// <summary>
        /// 操作日志写入
        /// </summary>
        /// <param name="username">登录人</param>
        /// <param name="logContent">日志内容</param>
        public static void WriteLog(string username,string logContent)
        {
            //此处以竖线分割操作人和内容，这个可随着实际情况编写，参数也根据项目需要自定
            Utilities.LogHelper.LogHelper.WriteLog(username + "|" + logContent, Utilities.LogHelper.Log4NetLevel.Debug);
        }


        /// <summary>
        /// 错误日志写入
        /// </summary>
        /// <param name="logContent">日志内容</param>
        public static void WriteLog(string logContent)
        {
            Utilities.LogHelper.LogHelper.WriteLog(logContent, Utilities.LogHelper.Log4NetLevel.Error);
        }

 webconfig数据库连接配置：

<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
    </startup>

  <connectionStrings>
    <add name="Conn" connectionString="Data Source=192.168.30.104;Initial Catalog = 数据库名;User Id = sa;Password = 123;Connect Timeout=5000" providerName="System.Data.SqlClient" />
  </connectionStrings>
</configuration>