Question

我正在尝试创建一个考勤表来记录学生参与的活动。创建新活动时会触发以下代码。创建新活动时，我想将所有学生记录插入考勤表，并将默认参与属性标记为false。（出勤属性是标记出勤率，设为0）

问题是无法填充考勤表。代码将停止在该行继续：numofRecordsAffected = command.ExecuteNonQuery（）;

我正试图从学生表中获取所有sigstudentid（s）。我不知道在这种情况下是否建议使用foreach（），但是我们将不胜感激。

我需要一个解决方案！

    public int InsertAttendance(int num)
        {
        SqlDataAdapter adapter = new SqlDataAdapter();
        SqlCommand command = new SqlCommand();
        SqlConnection connect = new SqlConnection();
        DataSet dataset = new DataSet();
        String sqlText = "SELECT * FROM Student";
        connect.ConnectionString = "Data Source=TECKISTTLE; Initial Catalog=Assignment;    Integrated Security=True";
        command.Connection = connect;
        command.CommandText = sqlText;

        int numofRecordsAffected = 0;

        adapter.SelectCommand = command;
        connect.Open();
        adapter.Fill(dataset, "StudentData");
        sqlText = "";

        foreach (DataRow item in dataset.Tables["StudentData"].Rows)
        {
            sqlText += " INSERT INTO Attendance(SIGStudentID, ActivityId, Attendance) VALUES(@SIGStudentID,@ActivityId,@Attendance); ";
            command.Parameters.Clear();
            command.Parameters.Add("@SIGStudentID", SqlDbType.Int);
            command.Parameters["@SIGStudentID"].Value = Convert.ToInt32(item["SIGStudentID"]);
            command.Parameters.Add("@ActivityId", SqlDbType.Int);
            command.Parameters["@ActivityId"].Value = num;
            command.Parameters.Add("@Attendance", SqlDbType.Bit);
            command.Parameters["@Attendance"].Value = 0;



        }
        numofRecordsAffected = command.ExecuteNonQuery();

        connect.Close();

        return numofRecordsAffected;
    }

Answer 1

当您将代码numofRecordsAffected = command.ExecuteNonQuery();放在foreach旁边时。它只执行一次。由于此代码是对表格中INSERT数据的实际陈述，因此INSERT只有ROW个最后一个。

试着把你的代码

numofRecordsAffected = command.ExecuteNonQuery();

在foreach区块内。然后每行INSERT。

    public int InsertAttendance(int num)
    {
    SqlDataAdapter adapter = new SqlDataAdapter();
    SqlCommand command = new SqlCommand();
    SqlConnection connect = new SqlConnection();
    DataSet dataset = new DataSet();
    String sqlText = "SELECT * FROM Student";
    connect.ConnectionString = "Data Source=TECKISTTLE; Initial Catalog=Assignment;    Integrated Security=True";
    command.Connection = connect;
    command.CommandText = sqlText;

    int numofRecordsAffected = 0;

    adapter.SelectCommand = command;
    connect.Open();
    adapter.Fill(dataset, "StudentData");
    sqlText = "";
    numofRecordsAffected = 0;
    sqlText = "INSERT INTO Attendance(SIGStudentID, ActivityId, Attendance) VALUES(@SIGStudentID,@ActivityId,@Attendance); ";
    command.CommandText = sqlText;
    foreach (DataRow item in dataset.Tables["StudentData"].Rows)
    {
        command.Parameters.Clear();
        command.Parameters.AddWithValue("@SIGStudentID", Convert.ToInt32(item["SIGStudentID"]);
        command.Parameters.AddWithValue("@ActivityId", num);
        command.Parameters.AddWithValue("@Attendance", 0);

        numofRecordsAffected += command.ExecuteNonQuery();

    }


    connect.Close();

    return numofRecordsAffected;
}

Answer 2

你可能通过使用循环来使它复杂化，并且可以做这样的事情：

"INSERT INTO Attendance(SIGStudentID, ActivityId, Attendance) select SIGStudentID, " + num + " as ActivityId, 0 as Attendance from Student;"

参考：

insert one column data from a table into other table, but the other column data will be specified dynamically

Insert all values of a table into another table in SQL

asp SQL Statement将多行记录插入表中

2 个答案: