正确安排代码

Question

我这里有这个代码：

public class clsDataLayer
{
    // This function saves the personnel data 
    public static bool SavePersonnel(string Database, string FirstName, string LastName,
                                     string PayRate, string StartDate, string EndDate)
    {

        bool recordSaved;

        try
        {
            // Retrieving information 
            OleDbConnection conn = new OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;" +
                                                       "Data Source=" + Database);
            conn.Open();
            OleDbCommand command = conn.CreateCommand();
            string strSQL;
            // Inserting information into the table 
            strSQL = "Insert into tblPersonnel " +
                     "(FirstName, LastName, PayRate, StartDate, EndDate) values ('" +
                     FirstName + "', '" + LastName + "', " + PayRate + ", '" + StartDate +
                    "', '" + EndDate + "')";
            // Gets the statement to execute at the data source 
            command.CommandType = CommandType.Text;
            command.CommandText = strSQL;
            // Executes the SQL statement and returns the number of rows 
            command.ExecuteNonQuery();
            // Closes the connection to the data source 
            conn.Close();
            recordSaved = true;
        }
        catch (Exception)
        {
            recordSaved = false;

        }

        return recordSaved;
    }


    // This function gets the user activity from the tblUserActivity 
    public static dsUserActivity GetUserActivity(string Database)
    {
        // States the classes used 
        dsUserActivity DS;
        OleDbConnection sqlConn;
        OleDbDataAdapter sqlDA;

        // Defines sqlConnclass and what each will consist of 
        sqlConn = new OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;" +
            "Data Source=" + Database);

        // Defines sqlDA and what each will consist of 
        sqlDA = new OleDbDataAdapter("select * from tblUserActivity", sqlConn);

        // Defines DS and what each will consist of 
        DS = new dsUserActivity();

        // Outputs the results from the information gathered 
        sqlDA.Fill(DS.tblUserActivity);

        // Starts over for a new user 
        return DS;
    }

    // This function saves the user activity 
    public static void SaveUserActivity(string Database, string FormAccessed)
    {
        // Defines the connection to the database 
        OleDbConnection conn = new OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;" +
            "Data Source=" + Database);
        conn.Open();
        OleDbCommand command = conn.CreateCommand();
        string strSQL;

        strSQL = "Insert into tblUserActivity (UserIP, FormAccessed) values ('" +
            GetIP4Address() + "', '" + FormAccessed + "')";

        command.CommandType = CommandType.Text;
        command.CommandText = strSQL;
        command.ExecuteNonQuery();
        conn.Close();
    }

    // This function gets the IP Address 
    public static string GetIP4Address()
    {
        string IP4Address = string.Empty;

        foreach (IPAddress IPA in
                    Dns.GetHostAddresses(HttpContext.Current.Request.UserHostAddress))
        {
            if (IPA.AddressFamily.ToString() == "InterNetwork")
            {
                IP4Address = IPA.ToString();
                break;
            }
        }

        if (IP4Address != string.Empty)
        {
            return IP4Address;
        }

        foreach (IPAddress IPA in Dns.GetHostAddresses(Dns.GetHostName()))
        {
            if (IPA.AddressFamily.ToString() == "InterNetwork")
            {
                IP4Address = IPA.ToString();
                break;
            }
        }

        return IP4Address;
    }




    public clsDataLayer()
    {

    }



    public static dsPersonnel GetPersonnel(string p)
    {
        throw new NotImplementedException();
    }
}

我需要添加此代码，但每次我都会收到一条错误消息，指出方法'GetPersonnel'没有重载需要'1'参数

// This function gets the user activity from the tblPersonnel 
    public static dsPersonnel GetPersonnel(string Database, string strSearch)
    {
        dsPersonnel DS;
        OleDbConnection sqlConn;
        OleDbDataAdapter sqlDA;

        //create the connection string  
        sqlConn = new OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;" +
        "Data Source=" + Database);

        string query;
        if (strSearch == "" || strSearch.Trim().Length == 0)
        {
            query = "SELECT * from tblPersonnel";
        }
        else
        {
            query = "select * from tblPersonnel where LastName = '" + strSearch + "'";
        }


        // Defines sqlDA and what each will consist of 
        sqlDA = new OleDbDataAdapter("select * from tblPersonnel", sqlConn);

        // Defines DS and what each will consist of 
        DS = new dsPersonnel();

        // Outputs the results from the information gathered 
        sqlDA.Fill(DS.tblPersonnel);

        // Starts over for a new user 
        return DS;
    }

    // This function saves the user activity 
    public static void SavePersonnel(string Database, string FormAccessed)
    {
        // Defines the connection to the database 
        OleDbConnection conn = new OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;" +
            "Data Source=" + Database);
        conn.Open();
        OleDbCommand command = conn.CreateCommand();
        string strSQL;

        strSQL = "Insert into tblPersonnel (UserIP, FormAccessed) values ('" +
            GetIP4Address() + "', '" + FormAccessed + "')";

        command.CommandType = CommandType.Text;
        command.CommandText = strSQL;
        command.ExecuteNonQuery();
        conn.Close();

    }

Answer 1

看起来你正在定义

public static dsPersonnel GetPersonnel

同一课程两次。我怀疑你是用两个arg版本替换单arg版本，但在某个地方你还在调用单arg版本。

我知道你不是要求这种输入，但我不能帮助自己......

您应该将OleDbConnections包装在一个使用块中，以确保它们如此关闭：

using (OleDbConnection conn = new OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;" +   
        "Data Source=" + Database))
{
    conn.Open();
    ...
{

不确定你的strSearch数据来自哪里，但是你正准备用这条线进行令人讨厌的SQL注入攻击：

query = "select * from tblPersonnel where LastName = '" + strSearch + "'";    

您应该使用SQL参数或存储过程。