我有两个组合框＆＃34;年＆＃34; ＆安培; ＆＃34;量＆＃34;在它们的顶部，我确实获得了用户信息的值，因为在使用用户ID文本框调用时，有文本框填充了正确的数据。
两个组合框也填充了正确的数据，但我必须手动选择年份和相应的数量。
当我拨打数据时，我需要帮助＃34;年＆＃34; ＆安培; ＆＃34;量＆＃34;应该在组合框中显示。当我选择一年时，金额应该相应地改变。最后但并非最不重要的是我的重置不是清除组合框。
using System;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.Data;
namespace dss
{
public partial class Form1 : Form
{
SqlConnection con = new SqlConnection("Data Source=USER-PC\\sqlexpress;Initial Catalog=JG_Test;Integrated Security=True");
public Form1()
{
InitializeComponent();
}
private void btnSearch_Click(object sender, EventArgs e)
{
cmbYear.Items.Clear();
string sql = "";
con.Open();
SqlCommand cmd = new SqlCommand();
try
{
sql += "SELECT m.MemberId, m.Name, m.Address, m.Cellular, m.Email, p.PaymentId, p.Year, p.Amount from Members as m";
sql += " INNER JOIN Payments as p ON m.MemberId = p.MemberId";
sql += " WHERE m.MemberId = '" + tbID.Text + "' ORDER BY p.Year ASC";
cmd.Connection = con;
cmd.CommandText = sql;
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
con.Close();
if(dt.Rows.Count >0)
{
for(int i = 0; i<=dt.Rows.Count -1;i++)
{
tbID.Text = dt.Rows[i]["MemberId"].ToString();
tbName.Text = dt.Rows[i]["Name"].ToString();
tbCellular.Text = dt.Rows[i]["Cellular"].ToString();
tbEmail.Text = dt.Rows[i]["Email"].ToString();
tbAddress.Text = dt.Rows[i]["Address"].ToString();
cmbAmount.Items.Add(dt.Rows[i]["Amount"].ToString());
cmbYear.Items.Add(dt.Rows[i]["Year"].ToString());
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message.ToString());
}
}
//This part displaying og the existing data from all the fileds corrssponding within the database//
private void btnAdd_Click(object sender, EventArgs e)
{
{
con.Open();
string Sql = "INSERT INTO Members ( MemberId, Name, Cellular, Email, Address ) VALUES " + " (@Id, @name, @cell, @email, @address)";
using (SqlCommand cmd = new SqlCommand(Sql, con))
{
cmd.CommandText = Sql;
cmd.Parameters.AddWithValue("@Id", tbID.Text);
cmd.Parameters.AddWithValue("@name", tbName.Text);
cmd.Parameters.AddWithValue("@cell", tbCellular.Text);
cmd.Parameters.AddWithValue("@email", tbCellular.Text);
cmd.Parameters.AddWithValue("@address", tbAddress.Text);
cmd.ExecuteNonQuery();
Sql = "INSERT INTO Payments ( MemberId, [Year], [Amount] ) VALUES " + " (@Id, Amount, Year)";
cmd.Parameters.Clear();
cmd.CommandText = Sql;
cmd.Parameters.AddWithValue("@Id", tbID.Text);
cmd.Parameters.AddWithValue("@year", cmbYear.Text);
cmd.Parameters.AddWithValue("@amount", cmbAmount.Text);
cmd.ExecuteNonQuery();
MessageBox.Show("Data Added");
tbID.Clear(); tbName.Clear(); tbCellular.Clear(); tbEmail.Clear(); tbAddress.Clear(); cmbYear.Items.Clear(); cmbAmount.Items.Clear();
con.Close();
}
}
}
//This part represents adding of new input data from all the fileds into the database//
private void btnUpdate_Click(object sender, EventArgs e)
{
try
{
SqlCommand cmd = new SqlCommand();
string Sql = "UPDATE Members SET MemberId = '" + tbID.Text + "', Name = '" + tbName.Text + "', Cellular = '" + tbCellular.Text + "', Email = '" + tbEmail.Text + "', Address = '" + tbAddress.Text + "' WHERE MemberId = '" + tbID.Text + "' ";
cmd.CommandText = Sql;
cmd.Connection = con;
con.Open();
cmd.ExecuteNonQuery();
con.Close();
Sql = "UPDATE Payments SET MemberId = '" + tbID.Text + "', Year = '" + cmbYear.Text + "', Amount = '" + cmbAmount.Text + "' WHERE MemberId = '" + tbID.Text + "' ";
cmd.CommandText = Sql;
cmd.Connection = con;
con.Open();
cmd.ExecuteNonQuery();
con.Close();
MessageBox.Show("Data Updated");
tbID.Clear(); tbName.Clear(); tbAddress.Clear(); tbCellular.Clear(); tbEmail.Clear(); cmbYear.Items.Clear(); cmbAmount.Items.Clear();
}
catch (Exception error)
{
MessageBox.Show(error.ToString());
}
}
//This part represents deleteing of input data from all the fileds into the database//
private void btnDelete_Click(object sender, EventArgs e)
{
try
{
SqlCommand cmd = new SqlCommand();
string Sql = "DELETE FROM Members WHERE MemberId = '" + tbID.Text + "' ";
cmd.CommandText = Sql;
cmd.Connection = con;
con.Open();
cmd.ExecuteNonQuery();
con.Close();
Sql = "DELETE FROM Payments WHERE MemberId = '" + tbID.Text + "' ";
cmd.CommandText = Sql;
cmd.Connection = con;
con.Open();
cmd.ExecuteNonQuery();
tbID.Clear(); tbName.Clear(); tbAddress.Clear(); tbCellular.Clear(); tbEmail.Clear(); cmbYear.Items.Clear(); cmbAmount.Items.Clear();
MessageBox.Show("Data Deleted");
con.Close();
}
catch (Exception error)
{
MessageBox.Show(error.ToString());
}
}
//This part represents clearing of input data from all the fileds//
private void btnReset_Click(object sender, EventArgs e)
{
tbID.Clear(); tbName.Clear(); tbAddress.Clear(); tbCellular.Clear(); tbEmail.Clear(); cmbYear.Items.Clear(); cmbAmount.Items.Clear();
}
//This part represents shuting down the application//
private void btnExit_Click(object sender, EventArgs e)
{
Application.Exit();
}
}
}
答案 0 :(得分：0)
我倾向于简化一些事情。将个人数据和财务数据视为两部分。
首先，请求个人数据 - 保持简单
private void btnSearch_Click(object sender, EventArgs e)
{
string sql = "SELECT MemberId, Name, Address, Cellular, Email FROM Members WHERE MemberId = @Id";
SqlConnection con = new SqlConnection("myconnectionstring");
SqlCommand cmd = new SqlCommand(sql,con);
cmd.Parameters.Add("@Id",SqlDbType.Int).Value = tbID.Text;
DataTable dt = new DataTable();
try
{
con.Open();
dt.Load(cmd.ExecuteReader());
con.Close();
}
catch (Exception ex)
{
con.Close();
Console.WriteLine(ex.Message);
}
tbID.Text = dt.Rows[0]["MemberId"].ToString();
tbName.Text = dt.Rows[0]["Name"].ToString();
tbCellular.Text = dt.Rows[0]["Cellular"].ToString();
tbEmail.Text = dt.Rows[0]["Email"].ToString();
tbAddress.Text = dt.Rows[0]["Address"].ToString();
}
一旦完成，转到第二部分 - 年/金额组合（几乎相同的代码）
string sql = "SELECT Year, Amount FROM Payments WHERE MemberId = @Id"
SqlConnection con = new SqlConnection("myconnectionstring");
SqlCommand cmd = new SqlCommand(sql,con);
cmd.Parameters.Add("@Id",SqlDbType.Int).Value = tbID.Text;
DataTable dt = new DataTable();
try
{
con.Open();
dt.Load(cmd.ExecuteReader());
con.Close();
}
catch (Exception ex)
{
con.Close();
Console.WriteLine(ex.Message);
}
cmbYear.DataSource = dt;
cmbYear.DisplayMember = "Year";
cmbYear.ValueMember = "Amount";
最后，使用
告诉文本框需要阅读的内容private void cmbYear_SelectionChangeCommitted(object sender, EventArgs e)
{
amountTxt.Text = cmbYear.SelectedValue.ToString();
}
SelectionChangeCommitted事件中
这应该让你排序！