数据库经常连接失败

Question

private void Open()
        {
            try
            {
                if (con.State == ConnectionState.Open)
                {
                    con.Close                
                }
                    con.Open();
            }
            catch (Exception)
            {
                System.Web.HttpContext.Current.Response.Write("数据库连接失败");
                System.Web.HttpContext.Current.Response.End();
            }
        }
我在访问数据库的时候 经常都会出现数据库失败的错误，数据库链接我就是用的上面的函数，每次运行应该都会先关闭数据库再重新链接，怎么还会出这个错误啊?

Answer 1

con.Close
这里是什么啊？

Answer 2

应该是关闭方法啊
con.Close（）；

Answer 3

不好意思，应该是这样的，
private void Open() 
        { 
            try 
            { 
                if (con.State == ConnectionState.Open) 
                { 
                    con.Close()                
                } 
                    con.Open(); 
            } 
            catch (Exception) 
            { 
                System.Web.HttpContext.Current.Response.Write("数据库连接失败"); 
                System.Web.HttpContext.Current.Response.End(); 
            } 
        } 循环是循环datatablepublic DataTable GetDataTable(string sqlstr)
        {
            
            SqlDataAdapter da = new SqlDataAdapter();
            DataTable datatable = new DataTable();
                Open();
                comm.CommandType = CommandType.Text;
                comm.CommandText = sqlstr;
                comm.Connection=con;
                da.SelectCommand = comm;
                da.Fill(datatable);            return datatable;
        }

Answer 4

        public virtual bool Open()
        {
            if (string.IsNullOrEmpty(this._dbConnection.ConnectionString))
            {
                throw new ArgumentNullException("ConnectionString");
            }
            if ((this._dbConnection != null) && (this._dbState == DataConnectionState.Opening))
            {
                this.Close();
            }
            try
            {
                this._dbConnection.Open();
            }
            catch (Exception ex)
            {
                if (this.LogEntry == null)
                {
                    throw ex;
                }
                this.LogEntry.RecordConnectionOpenError(ex);
            }
            return true;
        }

Answer 5

不需要打开手动打开　连接；
DataAdapter在填充数据时会自动打开连接，取得数据后，会关闭连接。

Answer 6

using(sqlconntion sqlcon=new sqlconntion())
{
   连接代码；.......
}
用这种一切OK

Answer 7

        DataTable datatable = new DataTable();    
        SqlDataAdapter sda = new SqlDataAdapter(sqlstr, con);
        sda.Fill(datatable);
        return datatable;