asp.net 数据库连接类。有问题，请大家给看一下哪里有问题。

Question

访问量 多的时候，数据库老是 连不上，，，大家看看是不是哪里没有关闭照成的。
 //当前连接的是第几个。
        static int count = 0;        //最大连接量
        static int maxCount = 300;
        static SqlConnection[] sqlConns = new SqlConnection[maxCount];        //自己创建自己
        static SqlConnections myConn = new SqlConnections();        //初始化
        private SqlConnections()
        {
            for (int i = 0; i < maxCount; i++)
            {
                sqlConns[i] = new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["ADOStr"].ToString());
            }
        }        //根据条件来获取不同的表，与字段。
        public static DataTable GetDataTable(String sqlTest, String tableName)
        {
            try
            {
                DataSet myDS = new DataSet();
                SqlDataAdapter myAdapater = new SqlDataAdapter(sqlTest, SqlConnections.GetSQLConnection());
                myAdapater.Fill(myDS, tableName);
                return myDS.Tables[tableName];
            }
            catch (SqlException sqlE)
            {
                return null;
            }
        }        // 获取数据库连接
        public static SqlConnection GetSQLConnection()
        {
            try
            {
                try
                {
                    sqlConns[count].Close();
                }
                catch (Exception eeX)
                {
                    sqlConns[count].Close();
                }
                return sqlConns[count];
            }
            finally
            {
                //当前个数自加。。
                if (count == (maxCount - 1))
                {
                    count = 0;
                }
                else
                {
                    count++;
                }
            }
        }

Answer 1

 try
  {
 DataSet myDS = new DataSet();
using (SqlConnection connection = 
        SqlConnections.GetSQLConnection()){
   SqlDataAdapter myAdapater = new SqlDataAdapter();
       myAdapater.SelectCommand = new SqlCommand(
            sqlTest, connection);
 myAdapater.Fill(myDS, tableName);
  return myDS.Tables[tableName];
  
}
 }
  catch (SqlException sqlE)
  {
  return null;
  }
 
 

Answer 2

+1 如此还是使用Using，让系统自己去关闭吧

Answer 3

try
{
DataSet myDS = new DataSet();
using (SqlConnection connection = 
SqlConnections.GetSQLConnection()){
SqlDataAdapter myAdapater = new SqlDataAdapter();
myAdapater.SelectCommand……

Answer 4

dataset 和 dataadpter 不需要关闭吗只用 using 能否全部关闭所有。？？？？请给位给予详细解答

Answer 5

为什么有两个try
  {
  try
  {为什么不用微软提供的SQLHELPER。？

Answer 6

为什么不用微软提供的SQLHELPER。？

Answer 7

USING及时释放
public abstract class DbHelperSQL
    {
        //数据库连接字符串(web.config来配置)
        //<add key="ConnectionString" value="server=127.0.0.1;database=DATABASE;uid=sa;pwd=" />        
        protected static string connectionString = ConfigurationSettings.AppSettings["ConnectionString"];
        public DbHelperSQL()
        {            
        }        #region 公用方法        public static int GetMaxID(string FieldName,string TableName)
        {
            string strsql = "select max(" + FieldName + ")+1 from " + TableName;
            object obj = GetSingle(strsql);
            if (obj == null)
            {
                return 1;
            }
            else
            {
                return int.Parse(obj.ToString());
            }
        }
        public static bool Exists(string strSql, params SqlParameter[] cmdParms)
        {
            object obj = GetSingle(strSql, cmdParms);
            int cmdresult;
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
                cmdresult = 0;
            }
            else
            {
                cmdresult = int.Parse(obj.ToString());
            }
            if (cmdresult == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }
        #endregion
#region  执行简单SQL语句        /// <summary>
        /// 执行SQL语句，返回影响的记录数
        /// </summary>
        /// <param name="SQLString">SQL语句</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSql(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {                
                using (SqlCommand cmd = new SqlCommand(SQLString,connection))
                {
                    try
                    {        
                        connection.Open();
                        int rows=cmd.ExecuteNonQuery();
                        return rows;
                    }
                    catch(System.Data.SqlClient.SqlException E)
                    {                    
                        connection.Close();
                        throw new Exception(E.Message);
                    }
                }                
            }
        }
/// <summary>
        /// 执行一条计算查询结果语句，返回查询结果（object）。
        /// </summary>
        /// <param name="SQLString">计算查询结果语句</param>
        /// <returns>查询结果（object）</returns>
        public static object GetSingle(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using(SqlCommand cmd = new SqlCommand(SQLString,connection))
                {
                    try
                    {
                        connection.Open();
                        object obj = cmd.ExecuteScalar();
                        if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
                        {                    
                            return null;
                        }
                        else
                        {
                            return obj;
                        }                
                    }
                    catch(System.Data.SqlClient.SqlException e)
                    {                        
                        connection.Close();
                        throw new Exception(e.Message);
                    }    
                }
            }
        }
        /// <summary>
        /// 执行查询语句，返回SqlDataReader
        /// </summary>
        /// <param name="strSQL">查询语句</param>
        /// <returns>SqlDataReader</returns>
        public static SqlDataReader ExecuteReader(string strSQL)
        {
            SqlConnection connection = new SqlConnection(connectionString);            
            SqlCommand cmd = new SqlCommand(strSQL,connection);                
            try
            {
                connection.Open();    
                SqlDataReader myReader = cmd.ExecuteReader();
                return myReader;
            }
            catch(System.Data.SqlClient.SqlException e)
            {                                
                throw new Exception(e.Message);
            }            
            
        }        
        /// 执行查询语句，返回DataSet
        public static DataSet Query(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    SqlDataAdapter command = new SqlDataAdapter(SQLString,connection);                
                    command.Fill(ds,"ds");
                }
                catch(System.Data.SqlClient.SqlException ex)
                {                
                    throw new Exception(ex.Message);
                }            
                return ds;
            }            
        }
}

Answer 8

dataset是断开试连接，取完数据自动断开连接，可能是内存不够吧。

Answer 9

最好用完让自动关闭连接，这样可以不占内存。for循环下面用using，可以尝试一下