System.Data.OleDb.OleDbException: 未指定的错误

2008-07-16 03:37:13 233 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

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    public OleDbDataReader ReadRow(OleDbConnection myConnection, string strSql)

    {

        myConnection = new OleDbConnection(connectionString);

        myConnection.Open();

        OleDbCommand myCommand = new OleDbCommand(strSql, myConnection);

        OleDbDataReader dr = myCommand.ExecuteReader();

        if (dr.Read())

        {

            myCommand.Dispose();

            return dr;

        }

        else

        {

            myCommand.Dispose();

            return null;

        }

    }

myConnection.Open();-----错误被定格在这行
就是网页来回测试一段时间之后就出现这情况，上次问了只能在调用函数的时候关闭连接不过一段时间还是出现这错误
获得OleDbDataReader 关闭连接的问题网上也找了好几天了一直没有解决反正就是一段时间就出现这个问题重新开启之后就又可以了
连接池满了应该那应该这样正确关闭呢望高手指点

...全文

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rczjp

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切换为时间正序

rczjp 2008-07-16

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太感谢大家了结帖~~~

lfywy 2008-07-16

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续上...



/// <summary>

        /// 返回指定Sql语句的OleDbDataReader，请注意，在使用后请关闭本对象，同时将自动调用closeConnection()来关闭数据库连接

        /// 方法关闭数据库连接

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        /// <param name="dr">传入的ref DataReader 对象</param>

        public static void DataReader(string sqlstr, ref OleDbDataReader dr)

        {

            try

            {

                openConnection();

                comm.CommandText = sqlstr;

                comm.CommandType = CommandType.Text;

                dr = comm.ExecuteReader(CommandBehavior.CloseConnection);

            }

            catch

            {

                try

                {

                    if (dr != null && !dr.IsClosed)

                        dr.Close();

                }

                catch

                {

                }

                finally

                {

                    closeConnection();

                }

            }

        }



        /// <summary>

        /// 返回指定Sql语句的DataSet

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        /// <returns>DataSet</returns>

        public static DataSet DataSet(string sqlstr)

        {

            DataSet ds = new DataSet();

            OleDbDataAdapter da = new OleDbDataAdapter();

            try

            {

                openConnection();

                comm.CommandType = CommandType.Text;

                comm.CommandText = sqlstr;

                da.SelectCommand = comm;

                da.Fill(ds);

            }

            catch (Exception ex)

            {

                throw new Exception(ex.Message);

            }

            finally

            {

                closeConnection();

            }

            return ds;

        }



        /// <summary>

        /// 返回指定Sql语句的DataSet

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        /// <param name="ds">传入的引用DataSet对象</param>

        public static void DataSet(string sqlstr, ref DataSet ds)

        {

            OleDbDataAdapter da = new OleDbDataAdapter();

            try

            {

                openConnection();

                comm.CommandType = CommandType.Text;

                comm.CommandText = sqlstr;

                da.SelectCommand = comm;

                da.Fill(ds);

            }

            catch (Exception ex)

            {

                throw new Exception(ex.Message);

            }

            finally

            {

                closeConnection();

            }

        }

        /// <summary>

        /// 返回指定Sql语句的DataTable

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        /// <returns>DataTable</returns>

        public static DataTable DataTable(string sqlstr)

        {

            OleDbDataAdapter da = new OleDbDataAdapter();

            DataTable Datatable = new DataTable();

            try

            {

                openConnection();

                comm.CommandType = CommandType.Text;

                comm.CommandText = sqlstr;

                da.SelectCommand = comm;

                da.Fill(Datatable);

            }

            catch (Exception ex)

            {

                throw new Exception(ex.Message);

            }

            finally

            {

                closeConnection();

            }

            return Datatable;

        }



        /// <summary>

        /// 执行指定Sql语句,同时给传入DataTable进行赋值 

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        /// <param name="dt">ref DataTable dt </param>

        public static void DataTable(string sqlstr, ref DataTable dt)

        {

            OleDbDataAdapter da = new OleDbDataAdapter();

            try

            {

                openConnection();

                comm.CommandType = CommandType.Text;

                comm.CommandText = sqlstr;

                da.SelectCommand = comm;

                da.Fill(dt);

            }

            catch (Exception ex)

            {

                throw new Exception(ex.Message);

            }

            finally

            {

                closeConnection();

            }

        }



        /// <summary>

        /// 返回指定Sql语句的DataView

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        /// <returns>DataView</returns>

        public static DataView DataView(string sqlstr)

        {

            OleDbDataAdapter da = new OleDbDataAdapter();

            DataView dv = new DataView();

            DataSet ds = new DataSet();

            try

            {

                openConnection();

                comm.CommandType = CommandType.Text;

                comm.CommandText = sqlstr;

                da.SelectCommand = comm;

                da.Fill(ds);

                dv = ds.Tables[0].DefaultView;

            }

            catch (Exception ex)

            {

                throw new Exception(ex.Message);

            }

            finally

            {

                closeConnection();

            }

            return dv;

        }

    }

lfywy 2008-07-16

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给你一个链接数据库方法类：



/// <summary>

    /// DataAccess 数据访问类

    /// By Lify

    /// </summary>

    public class DataAccess:System.Web.UI.Page

    {

        #region 属性

        protected static OleDbConnection conn = new OleDbConnection();

        protected static OleDbCommand comm = new OleDbCommand();

        #endregion

        public DataAccess()

        {

            //init();

        }

        #region 内部函数 静态方法中不会执行DataAccess()构造函数



        /// <summary>

        /// 打开数据库连接

        /// </summary>

        private static void openConnection()

        {

            if (conn.State == ConnectionState.Closed)

            {

                //SysConfig.ConnectionString 为系统配置类中连接字符串



                conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\"" + System.Configuration.ConfigurationSettings.AppSettings.Get("AccessRoot").ToString() + "\";Persist Security Info=True";

                comm.Connection = conn;

                try

                {

                    conn.Open();

                }

                catch (Exception e)

                {

                    throw new Exception(e.Message);

                }

            }

        }



        /// <summary>

        /// 关闭当前数据库连接

        /// </summary>

        private static void closeConnection()

        {

            if (conn.State == ConnectionState.Open)

                conn.Close();

            conn.Dispose();

            comm.Dispose();

        }

        #endregion



        /// <summary>

        /// 执行Sql查询语句

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        public static void ExecuteSql(string sqlstr)

        {

            try

            {

                openConnection();

                comm.CommandType = CommandType.Text;

                comm.CommandText = sqlstr;

                comm.ExecuteNonQuery();

            }

            catch (Exception ex)

            {

                throw new Exception(ex.Message);

            }

            finally

            {

                closeConnection();

            }

        }



        /// <summary>

        /// 执行Sql查询语句并返回第一行的第一条记录,返回值为object 使用时需要拆箱操作 -> Unbox

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        /// <returns>object 返回值 </returns>

        public static object ExecuteScalar(string sqlstr)

        {

            object obj = new object();

            try

            {

                openConnection();

                comm.CommandType = CommandType.Text;

                comm.CommandText = sqlstr;

                obj = comm.ExecuteScalar();

            }

            catch (Exception ex)

            {

                throw new Exception(ex.Message);

            }

            finally

            {

                closeConnection();

            }

            return obj;

        }



        /// <summary>

        /// 执行Sql查询语句,同时进行事务处理

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        public static void ExecuteSqlWithTransaction(string sqlstr)

        {

            closeConnection();

            openConnection();



            OleDbTransaction trans;

            trans = conn.BeginTransaction();

            comm.Transaction = trans;

            try

            {

                openConnection();

                comm.CommandType = CommandType.Text;

                comm.CommandText = sqlstr;

                comm.ExecuteNonQuery();

                trans.Commit();

            }

            catch

            {

                trans.Rollback();

            }

            finally

            {

                closeConnection();

            }

        }



        /// <summary>

        /// 返回指定Sql语句的OleDbDataReader，请注意，在使用后请关闭本对象，同时将自动调用closeConnection()来关闭数据库连接

        /// 方法关闭数据库连接

        /// </summary>

        /// <param name="sqlstr">传入的Sql语句</param>

        /// <returns>OleDbDataReader对象</returns>

        public static OleDbDataReader DataReader(string sqlstr)

        {

            OleDbDataReader dr = null;

            try

            {

                openConnection();

                comm.CommandText = sqlstr;

                comm.CommandType = CommandType.Text;

                dr = comm.ExecuteReader(CommandBehavior.CloseConnection);

            }

            catch

            {

                try

                {

                    dr.Close();

                    closeConnection();

                }

                catch

                {

                }

            }

            return dr;

        }

//待续 ......

路人乙e 2008-07-16

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myCommand.ExecuteReader(CommandBehavior.CloseConnection);

tootto 2008-07-16

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[Quote=引用 2 楼 rczjp 的回复:]
C# codeprotectedvoidIPInsert()
{
IPAddress ipAddress=newIPAddress();stringuser_ip=ipAddress.GetIPAddress();stringSelectIPSql="Select IpAddress From ipinfo Where IpAddress='"+user_ip+"'";
OleDbDataReader dr=QinMiData.ReadRow(myConnection, SelectIPSql);if(dr!=null)
{stringUpdateIPSql="Update ipinfo Set AddTime='"+DateTime.Now+"' where IpAddress='"+user_ip+"'";
…
[/Quote]

建议用两个独立的方法，不要把read和update放在一个方法里。

protected bool HasIpExisted(string userIp)
{
bool hasIpExisted = false;

//define connection, command, reader

myReader = myCommand.ExecuteReader();

hasIpExisted = myReader.HasRow;

//close reader, connection

return hasIpExisted;
}

protected void UpdateIpAddress()
{
string sqlCommand = string.Empty;

if ( HasIpExisted(ipAddress.GetIPAddress()))
{
sqlCommand = "update xxxx xxxxx";
}
else
{
sqlCommand = "insert into xxxxx";
}

..........
..........

}

whoami333 2008-07-16

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OleDbConnection con=new OleDBConnection("你的连接串");

不好意思，忘了。还有你的这个myConnection，最好要用的时候创建，用完即销毁，不要使用类似全局变量的这种方式。

whoami333 2008-07-16

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protected void IPInsert()
{
IPAddress ipAddress = new IPAddress();
string user_ip = ipAddress.GetIPAddress();
string SelectIPSql = "Select IpAddress From ipinfo Where IpAddress='" + user_ip + "'";
OleDbConnection con=new OleDBConnection();
con.Open();
OleDbCommand cmd=new OleDbCommand(SelectIPSql,con);
OleDbDataReader dr = cmd.ExecuteNonQuery();
if (!dr.HasRows)
{
string UpdateIPSql = "Update ipinfo Set AddTime='" + DateTime.Now + "' where IpAddress='" + user_ip + "'";
QinMiData.ExecuteSql(UpdateIPSql);
//dr.Close();
//myConnection.Close();
//myConnection.Dispose();
}
else
{
string InsertIPSql = "Insert into ipinfo(IpAddress,AddTime) values('" + user_ip + "','" + DateTime.Now + "')";
QinMiData.ExecuteSql(InsertIPSql);
//dr.Close();
//myConnection.Close();
//myConnection.Dispose();
}
dr.Close();
con.Close();
}

改成这样吧。

一品梅 2008-07-16

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没见你销毁connection

tootto 2008-07-16

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我想问题出在你试图返回一个reader,这样做行不通。

reader是同步操作数据库，增量读取数据（读完一条数据接着下一条，无法再返回上一条数据），所以你返回一个reader这样做是毫无意义的。

返回一个DataSet object是正道。

rczjp 2008-07-16

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恩都可以正常运行的
主要就是一段时间的操作之后就出现那个问题指示的错误就是OPEN那里。。

whoami333 2008-07-16

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public OleDbDataReader ReadRow(OleDbConnection myConnection, string strSql)
{
myConnection = new OleDbConnection(connectionString); //把这行注释掉试一下。
myConnection.Open();

hongqi162 2008-07-16

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connectionString里面有值么，输出一下看看，或者换个固定的路径试试

rczjp 2008-07-16

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另外我的是ACCESS数据库不知道是不是也有影响~~

rczjp 2008-07-16

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    protected void IPInsert()

    {

        IPAddress ipAddress = new IPAddress();

        string user_ip = ipAddress.GetIPAddress();

        string SelectIPSql = "Select IpAddress From ipinfo Where IpAddress='" + user_ip + "'";

        OleDbDataReader dr = QinMiData.ReadRow(myConnection, SelectIPSql);

        if (dr != null)

        {

            string UpdateIPSql = "Update ipinfo Set AddTime='" + DateTime.Now + "' where IpAddress='" + user_ip + "'";

            QinMiData.ExecuteSql(UpdateIPSql);

            dr.Close();

            myConnection.Close();

            myConnection.Dispose();

        }

        else

        {

            string InsertIPSql = "Insert into ipinfo(IpAddress,AddTime) values('" + user_ip + "','" + DateTime.Now + "')";

            QinMiData.ExecuteSql(InsertIPSql);

            dr.Close();

            myConnection.Close();

            myConnection.Dispose();

        }

    }

比如上面这个我都关闭了的很奇怪一段时间之后就不行了

Jinglecat 2008-07-16

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没见你的调用方法，没见你 close connection

System.Data.OleDb.OleDbException: 未指定的错误

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