在C＃中从查询到标签获取值

如何从查询结果中获取值到标签？

我有两个标签，一个是labelName ，另一个是labelDepartment

因此，当我运行查询时，如何从查询结果中获取值并使用c＃将其分配给标签？

这是我的Sql命令：

"SELECT tbl_staff.staffName,tbl_department.department FROM tbl_staff,tbl_logs,tbl_department WHERE tbl_staff.userID = tbl_logs." + listStaff.SelectedValue + " and tbl_staff.idDepartment = tbl_department.idDepartment;" 

这是C＃中的当前代码

 //Open SQL connection SqlConnection openCon = new SqlConnection(connString); openCon.Open(); string SQL = string.Format("SELECT tbl_staff.staffName,tbl_department.department FROM tbl_staff,tbl_logs,tbl_department WHERE tbl_staff.userID = tbl_logs.userID and tbl_staff.idDepartment = tbl_department.idDepartment" + listStaff.SelectedValue + ";"); SqlCommand command = new SqlCommand(SQL); SqlDataReader reader = command.ExecuteReader(); while(reader.Read()) { labelName.Text = reader["tbl_staff.staffName"]; labelDepartment.Text = reader["tbl_department.department"]; } 

注意：我们的记录只返回一行.. MS SQL和C＃..感谢您的帮助……;）

Answer 1

  string name = null; string department = null; string listStaff = "MylistStaff"; string sql = "SELECT tbl_staff.staffName,tbl_department.department " + "FROM tbl_staff,tbl_logs,tbl_department " + "WHERE tbl_staff.userID = tbl_logs." + listStaff + " and tbl_staff.idDepartment = tbl_department.idDepartment;"; //change this connection string... visit www.connectionstrings.com string connString = "Server=localhost; Database=myDatabaseName; Trusted_Connection=Yes"; using (SqlConnection conn = new SqlConnection(connString)) { conn.Open(); using (SqlCommand command = new SqlCommand(sql,conn)) { SqlDataReader reader = command.ExecuteReader(); while (reader.Read()) { name = reader[0] as string; department = reader[1] as string; //break for single row or you can continue if you have multiple rows... break; } } conn.Close(); } 

department和listStaff可以很容易地应用于标签文本，如：

DepartmentLabel.Text =部门;

Answer 2

您需要通过SQLDataReader读取结果

 SQLCommand command = new SQLCommand("your sql string here"); SQLDataReader reader = command.executeReader(); while(reader.read()) { set your label values here with reader["cloumn"] } 

Answer 3

您可以读取使用DataReader类返回的查询行的内容。 它有获取单个值的方法，或者您可以迭代每一行。 告诉我你查询返回了多少行，这样我就可以提供确切的代码。

Answer 4

检查一下 – 还要设置连接字符串以及此代码

 SQLCommand command = new SQLCommand(); command.CommandText = " SELECT tbl_staff.staffName,tbl_department.department FROM tbl_staff,tbl_logs,tbl_department WHERE tbl_staff.userID = tbl_logs." + listStaff.SelectedValue + " and tbl_staff.idDepartment = tbl_department.idDepartment "; SQLDataReader reader = command.executeReader(); while(reader.read()) { labelName.Text = reader.GetString(0); labelDepartment.Text = reader.GetString(1); } 

Answer 5

 //Open SQL connection SqlConnection openCon = new SqlConnection(connString); openCon.Open(); string SQL = string.Format("SELECT tbl_staff.staffName,tbl_department.department FROM tbl_staff,tbl_logs,tbl_department WHERE tbl_staff.userID = tbl_logs.userID and tbl_staff.idDepartment = tbl_department.idDepartment" + listStaff.SelectedValue + ";"); SqlCommand command = new SqlCommand(SQL); SqlDataReader reader = command.ExecuteReader(); while(reader.Read()) { labelName.Text = reader["tbl_staff.staffName"].ToString(); labelDepartment.Text = reader["tbl_department.department"].ToString(); } 

转换类型是您在代码中留下的内容….

Answer 6

尝试仅更改此项

 SqlConnection openCon = new SqlConnection(connString); openCon.Open(); string SQL = string.Format("SELECT tbl_staff.staffName,tbl_department.department FROM tbl_staff,tbl_logs,tbl_department WHERE tbl_staff.userID = tbl_logs.userID and tbl_staff.idDepartment = tbl_department.idDepartment" + listStaff.SelectedValue + ";"); SqlCommand command = new SqlCommand(SQL); SqlDataReader reader = command.ExecuteReader(); while(reader.Read()) { labelName.Text = reader["tbl_staff.staffName"].toString(); labelDepartment.Text = reader["tbl_department.department"].toString(); }` 

Answer 7

一种方法：

 private void getData() { DataTable dt = new DataTable(); SqlConnection connection = new SqlConnection("YOUR CONNECTION STRING HERE"); connection.Open(); SqlCommand sqlCmd = new SqlCommand(" SELECT tbl_staff.staffName,tbl_department.department FROM tbl_staff,tbl_logs,tbl_department WHERE tbl_staff.userID = tbl_logs." + listStaff.SelectedValue + " and tbl_staff.idDepartment = tbl_department.idDepartment", connection); SqlDataAdapter sqlDa = new SqlDataAdapter(sqlCmd); sqlCmd.Parameters.AddWithValue("@username",user); sqlDa.Fill(dt); if (dt.Rows.Count > 0) { lable.Text = dt.Rows[0]["staffName"].ToString(); //Where "staffName" is ColumnName } connection.Close(); } 

建议使用不在行查询中的存储过程来避免SQL注入攻击。

存储过程示例

Answer 8

使用您的查询填充数据集，然后从数据集中检索值并将其分配给您的标签。

让我们说你的数据集是DS然后：

 labelName.Text=DS.Tables[0]["tbl_staff.staffName"].tostring(); labelDepartment.Text=DS.Tables[0]["tbl_department.department"].tostring(); 

希望这可以帮助。