Question

我已经在本网站上检查了与此相似的其他问题，但他们的解决方案都没有对我有用。

我在C＃中使用SQL来尝试将新记录插入本地Access数据库。目前，我在运行时遇到this错误。

完整的方法：

public static void AddNewMusicFile(MusicFile m)
{
        long newID;
        int genreID = GenreDB.GetGenreID(m.AUDFIL_GENRE_NM);

        String strSQL = String.Empty;

        OleDbTransaction transaction = null;
        OleDbCommand cm = new OleDbCommand();
        OleDbConnection cn = new OleDbConnection(strConnString);

        cm.Connection = cn;

        cn.Open();

        transaction = cn.BeginTransaction();

        cm.Connection = cn;
        cm.Transaction = transaction;

        strSQL = "INSERT INTO AUDIOFILES_MSTR ";
        strSQL += "(";
        strSQL += "AUDFIL_TT, ";
        strSQL += "AUDFIL_RELEASE_DTM, ";
        strSQL += "AUDFIL_LENGTH, ";
        strSQL += "AUDFIL_GENRE_ID, ";
        strSQL += "AUDFIL_TYPE_ID, ";
        strSQL += "AUDFIL_ADD_DTM, ";
        strSQL += "AUDFIL_STAT_CD ";
        strSQL += ") VALUES (";
        strSQL += "@AUDFIL_TT, ";
        strSQL += "@AUDFIL_RELEASE_DTM, ";
        strSQL += "@AUDFIL_LENGTH, ";
        strSQL += "@AUDFIL_GENRE_ID, ";
        strSQL += "@AUDFIL_TYPE_ID, ";
        strSQL += "@AUDFIL_ADD_DTM, ";
        strSQL += "@AUDFIL_STAT_CD ";
        strSQL += ")";
        cm.CommandText = strSQL;

        OleDbParameter pm = new OleDbParameter("@AUDFIL_TT", OleDbType.Char, 163);
        pm.Direction = ParameterDirection.Input;
        pm.Value = m.AUDFIL_TT;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@AUDFIL_RELEASE_DTM", OleDbType.Date);
        pm.Direction = ParameterDirection.Input;
        pm.Value = m.AUDIL_RELEASE_DTM;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@AUDFIL_LENGTH", OleDbType.Integer);
        pm.Direction = ParameterDirection.Input;
        pm.Value = m.AUDFIL_LENGTH;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@genreID", OleDbType.Integer);
        pm.Direction = ParameterDirection.Input;
        pm.Value = genreID;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@AUDFIL_TYPE_ID", OleDbType.Integer);
        pm.Direction = ParameterDirection.Input;
        pm.Value = m.AUDFIL_TYPE_ID;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@AUDFIL_ADD_DTM", OleDbType.Date);
        pm.Direction = ParameterDirection.Input;
        pm.Value = m.AUDFIL_ADD_DTM;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@AUDFIL_STAT_CD", OleDbType.VarChar, 1);
        pm.Direction = ParameterDirection.Input;
        pm.Value = 'A';
        cm.Parameters.Add(pm);

        cm.ExecuteNonQuery();

        cm.CommandText = "SELECT @@IDENTITY AS AUDFIL_ID;";
        newID = int.Parse(cm.ExecuteScalar().ToString());

        strSQL = "INSERT INTO MUSICFILES_SPLM ";
        strSQL += "(";
        strSQL += "AUDFIL_ID, ";
        strSQL += "MSC_ARTIST_NM, ";
        strSQL += "MSC_ALBUM_NM, ";
        strSQL += "MSC_PRODUCER_NM, ";
        strSQL += "MSC_LABEL_NM ";
        strSQL += ") VALUES (";
        strSQL += "@AUDFIL_ID, ";
        strSQL += "@MSC_ARTIST_NM, ";
        strSQL += "@MSC_ALBUM_NM, ";
        strSQL += "@MSC_PRODUCER_NM, ";
        strSQL += "@MSC_LABEL_NM ";
        strSQL += ")";
        cm.CommandText = strSQL;

        pm = new OleDbParameter("@AUDFIL_ID", OleDbType.Integer);
        pm.Direction = ParameterDirection.Input;
        pm.Value = newID;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@MSC_ARTIST_NM", OleDbType.Char, 50);
        pm.Direction = ParameterDirection.Input;
        pm.Value = m.MSC_ARTIST_NM;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@MSC_ALBUM_NM", OleDbType.Char, 163);
        pm.Direction = ParameterDirection.Input;
        pm.Value = m.MSC_ALBUM_NM;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@MSC_PRODUCER_NM", OleDbType.Char, 50);
        pm.Direction = ParameterDirection.Input;
        pm.Value = m.MSC_PRODUCER_NM;
        cm.Parameters.Add(pm);

        pm = new OleDbParameter("@MSC_LABEL_NM", OleDbType.Char, 30);
        pm.Direction = ParameterDirection.Input;
        pm.Value = m.MSC_LABEL_NM;
        cm.Parameters.Add(pm);

        cm.ExecuteNonQuery();
        transaction.Commit();
}

错误在提交事务之前的最后cm.ExecuteNonQuery()处触发。

我正在尝试添加数据的表是这样的：

Table Structure

创建音乐文件对象并调用add方法的方法：

private void btnAdd_Click(object sender, EventArgs e)
{
        MusicFile m = new MusicFile();
        m.MSC_ARTIST_NM = txtArtist.Text;
        m.MSC_ALBUM_NM = txtAlbum.Text;
        m.MSC_PRODUCER_NM = txtProducer.Text;
        m.MSC_LABEL_NM = txtLabel.Text;

        m.AUDFIL_TT = txtTitle.Text;
        m.AUDIL_RELEASE_DTM = dtpReleaseDate.Value;
        m.AUDFIL_TYPE_ID = 1;
        m.AUDFIL_LENGTH = (((long)nudHours.Value * 3600) + ((long)nudMinutes.Value * 60) + (long)nudSeconds.Value);
        m.AUDFIL_GENRE_NM = cbxGenre.SelectedItem.ToString();
        m.AUDFIL_ADD_DTM = Convert.ToDateTime(DateTime.Now.ToShortDateString());

        AudioBaseDB.AddNewMusicFile(m);
        MessageBox.Show("Record Added Successfully");
}

我现在已经被困在这几个小时了，无法找到导致错误的参数。

Answer 1

您对三种不同的执行使用相同的命令。问题是你没有清除参数集合，所以你试图在第三次执行时插入第一组参数

....
// First execution with the set of parameters defined before
cm.ExecuteNonQuery();

// Second execution, no parameters required here
cm.CommandText = "SELECT @@IDENTITY AS AUDFIL_ID;";
newID = int.Parse(cm.ExecuteScalar().ToString());

// Before starting to add the parameters for the final INSERT
// clear the collection from the previous ones
cm.Parameters.Clear();
....

在OleDb中，参数不能通过名称识别，而是通过其位置识别添加了与第一个INSERT相关的第一个参数块意味着OleDb将在执行最终INSERT时将第一个参数添加到集合（@AUDFIL_TT）作为第一个参数占位符（@AUDFIL_ID）的值。幸运的是，数据类型不匹配，您会收到错误消息。如果偶然的话，所有类型的数据类型都是正确的，那么你就会在第二个表中输入错误的数据。

个人注意事项：我不喜欢以这种方式连接命令文本，而是使用带有@字符的verbatim string literal。我发现它更具可读性。

strSQL = @"INSERT INTO AUDIOFILES_MSTR
             (AUDFIL_TT,AUDFIL_RELEASE_DTM,AUDFIL_LENGTH, 
              AUDFIL_GENRE_ID,AUDFIL_TYPE_ID,AUDFIL_ADD_DTM, 
              AUDFIL_STAT_CD) 
           VALUES 
             (@AUDFIL_TT,@AUDFIL_RELEASE_DTM,@AUDFIL_LENGTH,
              @AUDFIL_GENRE_ID, @AUDFIL_TYPE_ID, @AUDFIL_ADD_DTM,
              @AUDFIL_STAT_CD)";

C＃访问：INSERT SQL语句的条件表达式错误中的数据类型不匹配

1 个答案: