英文:
How to display the First Name and Last Name in the Lable by the ID of the profile you are logged into?
问题
以下是您要翻译的部分：
我正在创建一个带有MySQL数据库的WPF应用程序，我编写了以下代码，以便用户名将显示在标签中，但出于某种原因，它只给我显示了数据库中的最后一个用户。我该如何做才能登录到帐户并只看到与之相关的信息？也就是说，我登录到用户1，然后在字段中只看到用户1，例如不是用户101。
我尝试添加一个ID字段，但在这样做之后，我的所有标签都开始填充表中的最后一个ID。
为了能够显示姓和名，您需要：
创建一个类，其中将存储变量：
用户ID
用户名
```csharp
public class global
{
public static int userid;
public static string username;
}
接下来，在检查字符串是否已填充时，您需要声明变量并将其转换为字符串
DB db = new DB();
string userName = TB_Name.Text;
string userPass = PB_Password.Password;
DataTable table = new DataTable();
MySqlDataAdapter adapter = new MySqlDataAdapter();
MySqlCommand command = new MySqlCommand("SELECT * FROM Login WHERE Login = @uL AND Password = @uP AND Role = 2", db.GetConnection());
command.Parameters.Add("@uL", MySqlDbType.VarChar).Value = userName;
command.Parameters.Add("@uP", MySqlDbType.VarChar).Value = userPass;
adapter.SelectCommand = command;
adapter.Fill(table);
if (table.Rows.Count > 0)
{
global.userid = Convert.ToInt32(table.Rows[0]["ID"].ToString());
global.username = table.Rows[0]["Login"].ToString();
UserPanel();
}
之后，在用户行中，您需要将用户ID的值分配给带有ID的标签
string query = $"SELECT FirstName, LastName, ID, img FROM Login WHERE ID = {ID_Label.Content = global.userid}";
MySqlCommand cmd = new MySqlCommand(query, db.GetConnection());
db.openConnection();
MySqlDataReader myReader = cmd.ExecuteReader();
try
{
while (myReader.Read())
{
FN_Label.Content = myReader.GetString("FirstName");
LN_Label.Content = myReader.GetString("LastName");
}
}
<details>
<summary>英文:</summary>
I am creating a WPF application with a MySQL database, I wrote the following code so that the username would be displayed in the Lable, but for some reason it gives me only the last user in my database. How can I make it so that I would log into the account and see information only on it? Those. I go under user 1 and I will see user 1 in the field, and for example not user 101
``` string conn =
"server=; username=; password=; database=u1831430_excurtion";
MySqlConnection connectionString = new MySqlConnection(conn);
MySqlCommand command = connectionString.CreateCommand();
command.CommandText = $"SELECT `FirstName` FROM `Login` WHERE 1";
command.CommandText = $"SELECT `LastName` FROM `Login` WHERE 1";
//command.CommandText = $"SELECT `ID` FROM `Login` WHERE 1";
MySqlDataReader myReader;
try
{
connectionString.Open();
myReader = command.ExecuteReader();
while (myReader.Read())
{
//ID_Label.Content = myReader[0].ToString();
FN_Label.Content = myReader[0].ToString();
LN_Label.Content = myReader[0].ToString();
}
}
I tried to add a field with an ID, but after I did that, all my Labels began to fill in with the last ID from the table
To make it possible to display the last name and first name, you need:
Create a class where variables will be stored:
user ID
Username
public class global
{
public static int userid;
public static string username;
}
Next, when checking strings for fullness, you need to declare variables and translate them into a string
DB db = new DB();
string userName = TB_Name.Text;
string userPass = PB_Password.Password;
DataTable table = new DataTable();
MySqlDataAdapter adapter = new MySqlDataAdapter();
MySqlCommand command = new MySqlCommand("SELECT * FROM Login WHERE Login = @uL AND Password = @uP AND Role = 2" , db.GetConnection());
command.Parameters.Add("@uL", MySqlDbType.VarChar).Value = userName;
command.Parameters.Add("@uP", MySqlDbType.VarChar).Value = userPass;
adapter.SelectCommand = command;
adapter.Fill(table);
if (table.Rows.Count > 0)
{
global.userid = Convert.ToInt32(table.Rows[0]["ID"].ToString());
global.username = table.Rows[0]["Login"].ToString();
UserPanel();
}
After that, in the user line, you need to assign the value of the user ID to your label with the ID
string query = $"SELECT FirstName, LastName, ID, img FROM Login WHERE ID = {ID_Label.Content = global.userid}";
MySqlCommand cmd = new MySqlCommand(query, db.GetConnection());
db.openConnection();
MySqlDataReader myReader = cmd.ExecuteReader();
try
{
while (myReader.Read())
{
FN_Label.Content = myReader.GetString("FirstName");
LN_Label.Content = myReader.GetString("LastName");
}
}
答案1
得分: 0
为了能够显示姓和名，需要执行以下步骤：
创建一个类来存储变量：
用户ID
用户名
public class global
{
public static int userid;
public static string username;
}
接下来，在检查字符串是否为空时，需要声明变量并将它们转换为字符串：
DB db = new DB();
string userName = TB_Name.Text;
string userPass = PB_Password.Password;
DataTable table = new DataTable();
MySqlDataAdapter adapter = new MySqlDataAdapter();
MySqlCommand command = new MySqlCommand("SELECT * FROM Login WHERE Login = @uL AND Password = @uP AND Role = 2", db.GetConnection());
command.Parameters.Add("@uL", MySqlDbType.VarChar).Value = userName;
command.Parameters.Add("@uP", MySqlDbType.VarChar).Value = userPass;
adapter.SelectCommand = command;
adapter.Fill(table);
if (table.Rows.Count > 0)
{
global.userid = Convert.ToInt32(table.Rows[0]["ID"].ToString());
global.username = table.Rows[0]["Login"].ToString();
UserPanel();
}
然后，在用户行中，需要将用户ID的值分配给带有ID的标签：
string query = $"SELECT FirstName, LastName, ID, img FROM Login WHERE ID = {ID_Label.Content = global.userid}";
MySqlCommand cmd = new MySqlCommand(query, db.GetConnection());
db.openConnection();
MySqlDataReader myReader = cmd.ExecuteReader();
try
{
while (myReader.Read())
{
FN_Label.Content = myReader.GetString("FirstName");
LN_Label.Content = myReader.GetString("LastName");
}
}
英文:
To make it possible to display the last name and first name, you need:
Create a class where variables will be stored:
user ID
Username
public class global
{
public static int userid;
public static string username;
}
Next, when checking strings for fullness, you need to declare variables and translate them into a string
DB db = new DB();
string userName = TB_Name.Text;
string userPass = PB_Password.Password;
DataTable table = new DataTable();
MySqlDataAdapter adapter = new MySqlDataAdapter();
MySqlCommand command = new MySqlCommand("SELECT * FROM Login WHERE Login = @uL AND Password = @uP AND Role = 2" , db.GetConnection());
command.Parameters.Add("@uL", MySqlDbType.VarChar).Value = userName;
command.Parameters.Add("@uP", MySqlDbType.VarChar).Value = userPass;
adapter.SelectCommand = command;
adapter.Fill(table);
if (table.Rows.Count > 0)
{
global.userid = Convert.ToInt32(table.Rows[0]["ID"].ToString());
global.username = table.Rows[0]["Login"].ToString();
UserPanel();
}
After that, in the user line, you need to assign the value of the user ID to your label with the ID
string query = $"SELECT FirstName, LastName, ID, img FROM Login WHERE ID = {ID_Label.Content = global.userid}";
MySqlCommand cmd = new MySqlCommand(query, db.GetConnection());
db.openConnection();
MySqlDataReader myReader = cmd.ExecuteReader();
try
{
while (myReader.Read())
{
FN_Label.Content = myReader.GetString("FirstName");
LN_Label.Content = myReader.GetString("LastName");
}
}
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