[英]Retrieving data from SQL server 2008r2 using winforms
我正在創建ac#Windows窗體應用程序,它將從已在sql server2008r2中創建的數據庫中檢索數據。 我的應用程序中有2種獲勝形式,第一種是獲取登錄詳細信息,第二種是顯示與給定UserID和密碼相關的數據。 我無法將數據保存到第二個表格中。 這是我的代碼:
** * **** 第一種形式 * ** *
public partial class FormLog_in : Form
{
SqlConnection con = new SqlConnection("Data source=CHINTHAK-PC ; Initial Catalog=FlintecTest; Integrated Security = yes;");
SqlDataAdapter da = new SqlDataAdapter();
SqlCommand cmd = new SqlCommand();
public FormLog_in()
{
InitializeComponent();
}
private void btnLogIn_Click(object sender, EventArgs e)
{
if (!(string.IsNullOrEmpty(txtUserName.Text)) && !(string.IsNullOrEmpty(txtPassword.Text)))
{
con.Open();
string query = "SELECT count(*) FROM LogIn WHERE UesrName=@1 AND PassWord=@2 ";
cmd = new SqlCommand(query, con);
cmd.Parameters.Add("@1", SqlDbType.NVarChar).Value = txtUserName.Text;
cmd.Parameters.Add("@2", SqlDbType.NVarChar).Value = txtPassword.Text;
int count = Convert.ToInt32(cmd.ExecuteScalar());
con.Close();
if (count > 0)
{
MessageBox.Show("Valid Username and Password");
Welcome f1 = new Welcome();
f1.Show();
}
else
MessageBox.Show("Invalid Username or Password try again");
}
* **** 第二種形式 * *
public partial class Welcome : Form
{
string query = null;
SqlConnection con = new SqlConnection("Data source=CHINTHAK-PC ; Initial Catalog=FlintecTest; Integrated Security = yes;");
SqlDataAdapter da = new SqlDataAdapter();
BindingSource userTable = new BindingSource();
DataSet ds = new DataSet();
public Welcome()
{
InitializeComponent();
}
private void Welcome_Load(object sender, EventArgs e)
{
query = "SELECT * FROM Users WHERE UserName=@x AND Users.Password=@y ";//x should be given username by current login
da.SelectCommand = new SqlCommand(query, con); //y should be given password by current login
ds.Clear();
da.Fill(ds, "usr");
userTable.DataSource = ds.Tables["usr"];
txtFristName.DataBindings.Add(new Binding("Text", userTable, "FirstName"));
txtLastName.DataBindings.Add(new Binding("Text", userTable, "LastName"));
txtAddress.DataBindings.Add(new Binding("Text", userTable, "Address"));
txtTelephone.DataBindings.Add(new Binding("Text", userTable, "Telephone"));
txtEmail.DataBindings.Add(new Binding("Text", userTable, "Email"));
txtFax.DataBindings.Add(new Binding("Text", userTable, "Fax"));
txtSection.DataBindings.Add(new Binding("Text", userTable, "Section"));
txtPosition.DataBindings.Add(new Binding("Text", userTable, "Position"));
}
}
為什么不更改您的歡迎表單中的構造函數以接收參數。
public Welcome(String usr, String pword)
{
InitializeComponent();
this.Username=usr;
this.Password=pword; // you should have a form of encryption for your password
}
因此,當您致電時,您會執行以下操作:
Welcome f1 = new Welcome(txtUsername.Text,txtPassword.Text);
然后以歡迎形式添加屬性,例如:
private String Username { get; set; }
private String Password { get; set; }
然后在歡迎表單加載中添加2個參數:
cmd.Parameters.Add("@x", SqlDbType.NVarChar).Value = Username;
cmd.Parameters.Add("@y", SqlDbType.NVarChar).Value = Password;
您可以使用構造函數來解決您的問題
當您點擊“登錄”按鈕(假設有一個按鈕)時,您可以:
private void login_Click(object sender, System.EventArgs e)
{
Form2 frm=new Form2(userName.text,password.tex);
frm.Show();
}
您的第二個表單構造函數可以是:
public Form2(string user, string pass)
{
InitializeComponent();
//Save your parameters here so you can use them with the query
}
還有其他方法可以做到這一點。 http://www.codeproject.com/Articles/14122/Passing-Data-Between-Forms
當然,您不能以第二種形式從數據庫檢索數據
1-您沒有將x和y參數發送到第二個表單
Form2 frm = new Form2(userName.text,password.tex);
frm.Show();
2-必須將x和y傳遞給SqlCommand
的查詢並執行查詢
query = "SELECT * FROM Users WHERE UserName='"+ x +"'AND Password='"+y+"'";
最終代碼
在表格一中
if (count > 0)
{
MessageBox.Show("Valid Username and Password");
Welcome f1 = new Welcome( txtUserName.Text,txtPassword.Text);
f1.Show();
}
在表格二中
string x, y;
public Welcome(String usr, String pword)
{
InitializeComponent();
x = usr; y = pword;
}
private void Welcome_Load(object sender, EventArgs e)
{
query = "SELECT * FROM Users WHERE UserName='"+ x +"'AND Password='"+y+"'";
cmd.SelectCommand = new SqlCommand(query ,con);
ds.Clear();
cmd.Fill(ds);
userTable.DataSource = ds.Tables[0];
txtFristName.DataBindings.Add(new Binding("Text", userTable, "FirstName"));
txtLastName.DataBindings.Add(new Binding("Text", userTable, "LastName"));
txtAddress.DataBindings.Add(new Binding("Text", userTable, "Address"));
txtTelephone.DataBindings.Add(new Binding("Text", userTable, "Telephone"));
txtEmail.DataBindings.Add(new Binding("Text", userTable, "Email"));
txtFax.DataBindings.Add(new Binding("Text", userTable, "Fax"));
txtSection.DataBindings.Add(new Binding("Text", userTable, "Section"));
txtPosition.DataBindings.Add(new Binding("Text", userTable, "Position"));
}
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