C#遍历数据表中的行

我正在尝试遍历一个2列表中的行，以对照一个名称检查每行中的1个字段。一旦找到，我想编写代码将相应的数字分配给OurNumber变量，并通过将gottenumber设置为true来打破循环

下面是我正在使用的代码：

    private void BtnDelete_Click(object sender, EventArgs e)// Sends to ConfirmDeleteEMP Form 
    {            
        ConfirmDeleteEMP form = new ConfirmDeleteEMP();
        DataTable table = new DataTable();
        string connstring = @"Provider = Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\HoliPlanData.accdb;Persist Security Info=False";
        using (OleDbConnection conn = new OleDbConnection(connstring))
        {
            string query = "SELECT PayrollNo, (FirstName + ' ' + LastName) AS NAME FROM [Employee]";                 
            OleDbDataAdapter adapter = new OleDbDataAdapter(query, conn);
            adapter.Fill(table);                                        
        }

        string SelectedName = DropBoxEmp.Text;            
        bool GotTheNumber = false;
        int OurNumber = 0;
        while (!GotTheNumber)
        {
            foreach (DataRow ThisRow in table.Rows)
            {
                if (SelectedName = (table.Rows[ThisRow])) 
                {
                    OurNumber = ///THATNUMBER///;
                    GotTheNumber = true;
                }  
            }
        }

        MessageBox.Show(SelectedName);
        var GoodNumber = (table.Rows[OurNumber]["PayrollNo"].ToString());
        form.PassValueName = SelectedName;
        form.PassSelectedPayroll = GoodNumber;               
        form.Tag = this;
        form.Show(this);
        Hide();
    }

---

我不知道从If声明中可以得到什么，因此非常感谢您的帮助。

嗯，很难猜到您到底有什么问题。但是我想你只是想从现在这一行拿到薪水，不是吗

关于下一条线

var GoodNumber = (table.Rows[OurNumber]["PayrollNo"].ToString());

。。。我想你可以打电话：

if (...)
{
    OurNumber = ThisRow["PayrollNo"].ToString();
    GotTheNumber = true;
}

但是，我不知道您对以下if条件做了什么，也不知道这是否真的符合您的要求：

if (SelectedName = (table.Rows[ThisRow]))
{
...
}

---

嗯，很难猜出你到底有什么问题。但是我想你只是想从现在这一行拿到薪水，不是吗

关于下一条线

var GoodNumber = (table.Rows[OurNumber]["PayrollNo"].ToString());

。。。我想你可以打电话：

if (...)
{
    OurNumber = ThisRow["PayrollNo"].ToString();
    GotTheNumber = true;
}

但是，我不知道您对以下if条件做了什么，也不知道这是否真的符合您的要求：

if (SelectedName = (table.Rows[ThisRow]))
{
...
}

---

循环浏览客户端程序中的行正是您不想做的事情。让数据库为您完成这项工作。试试这个：

private void BtnDelete_Click(object sender, EventArgs e)// Sends to ConfirmDeleteEMP Form 
{     
    object result;       
    string query = "SELECT PayrollNo FROM [Employee] WHERE FirstName + ' ' + LastName = ?"; 
    string connstring = @"Provider = Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\HoliPlanData.accdb;Persist Security Info=False";

    using (OleDbConnection conn = new OleDbConnection(connstring))
    using (OleDbCommand cmd = new OleDbCommand(query, conn))
    {
        //guessing at type and length here
        cmd.Parameters.Add("?", OleDbType.VarWChar, 50).Value = DropBoxEmp.Text;

        conn.Open();
        result = cmd.ExecuteScalar();                                        
    }

    if (result != null && result != DBNull.Value)
    {
        ConfirmDeleteEMP form = new ConfirmDeleteEMP();
        form.PassValueName = DropBoxEmp.Text;
        form.PassSelectedPayroll = (int)result;
        form.Tag = this;

        form.Show(this);
        Hide();
    }                    
}

如果您确实希望根据所有原因（速度较慢，需要编写更多代码，并且更容易出错）循环行，则可以执行以下操作：

private void BtnDelete_Click(object sender, EventArgs e)// Sends to ConfirmDeleteEMP Form 
{                   
    DataTable table = new DataTable();
    string query = "SELECT PayrollNo, (FirstName + ' ' + LastName) AS NAME FROM [Employee]"; 
    string connstring = @"Provider = Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\HoliPlanData.accdb;Persist Security Info=False";
    using (OleDbConnection conn = new OleDbConnection(connstring))
    {                    
        OleDbDataAdapter adapter = new OleDbDataAdapter(query, conn);
        adapter.Fill(table);                                        
    }

    int PayrollNumber = 0;
    foreach (DataRow ThisRow in table.Rows)
    {
        if (DropBoxEmp.Text == ThisRow["NAME"])
        {
            PayrollNumber = (int)ThisRow["PayrollNo"];
            break;
        }  
    }
    //the whole loop could also be consolidated to this:
    //PayrollNumber = (int)table.Rows.First(r => r["NAME"] == DropBoxEmp.Text)["PayrollNo"];

    ConfirmDeleteEMP form = new ConfirmDeleteEMP();
    form.PassValueName = DropBoxEmp.Text;
    form.PassSelectedPayroll = PayrollNumber ;               
    form.Tag = this;
    form.Show(this);
    Hide();
}

---

循环浏览客户端程序中的行正是您不想做的事情。让数据库为您完成这项工作。试试这个：

private void BtnDelete_Click(object sender, EventArgs e)// Sends to ConfirmDeleteEMP Form 
{     
    object result;       
    string query = "SELECT PayrollNo FROM [Employee] WHERE FirstName + ' ' + LastName = ?"; 
    string connstring = @"Provider = Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\HoliPlanData.accdb;Persist Security Info=False";

    using (OleDbConnection conn = new OleDbConnection(connstring))
    using (OleDbCommand cmd = new OleDbCommand(query, conn))
    {
        //guessing at type and length here
        cmd.Parameters.Add("?", OleDbType.VarWChar, 50).Value = DropBoxEmp.Text;

        conn.Open();
        result = cmd.ExecuteScalar();                                        
    }

    if (result != null && result != DBNull.Value)
    {
        ConfirmDeleteEMP form = new ConfirmDeleteEMP();
        form.PassValueName = DropBoxEmp.Text;
        form.PassSelectedPayroll = (int)result;
        form.Tag = this;

        form.Show(this);
        Hide();
    }                    
}

如果您确实希望根据所有原因（速度较慢，需要编写更多代码，并且更容易出错）循环行，则可以执行以下操作：

private void BtnDelete_Click(object sender, EventArgs e)// Sends to ConfirmDeleteEMP Form 
{                   
    DataTable table = new DataTable();
    string query = "SELECT PayrollNo, (FirstName + ' ' + LastName) AS NAME FROM [Employee]"; 
    string connstring = @"Provider = Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\HoliPlanData.accdb;Persist Security Info=False";
    using (OleDbConnection conn = new OleDbConnection(connstring))
    {                    
        OleDbDataAdapter adapter = new OleDbDataAdapter(query, conn);
        adapter.Fill(table);                                        
    }

    int PayrollNumber = 0;
    foreach (DataRow ThisRow in table.Rows)
    {
        if (DropBoxEmp.Text == ThisRow["NAME"])
        {
            PayrollNumber = (int)ThisRow["PayrollNo"];
            break;
        }  
    }
    //the whole loop could also be consolidated to this:
    //PayrollNumber = (int)table.Rows.First(r => r["NAME"] == DropBoxEmp.Text)["PayrollNo"];

    ConfirmDeleteEMP form = new ConfirmDeleteEMP();
    form.PassValueName = DropBoxEmp.Text;
    form.PassSelectedPayroll = PayrollNumber ;               
    form.Tag = this;
    form.Show(this);
    Hide();
}

---

嗨，Joel，我喜欢让数据库帮我检查的想法，刚刚尝试了最上面的代码，但在“form.PassSelectedPayroll=（int）result”行中将int转换为字符串时出现语法错误；这是什么原因？因为您将

PassSelectedPayroll

属性定义为字符串。嗨，Joel，我喜欢让数据库为我检查的想法，刚刚尝试了最上面的代码，但在“form.PassSelectedPayroll=（int）result”行中得到了将int转换为字符串的语法错误；这是什么原因？因为您将

PassSelectedPayroll

属性定义为字符串。