SQLite错误提供给命令的参数不足 [英] SQLite error Insufficient parameters supplied to the command

问题描述

我在注释/ ********** /的行上收到错误提供给命令的参数不足。我不知道它有什么问题？请帮帮我？

I got the error "Insufficient parameters supplied to the command" on the line I comment /**********/. I don't know what's wrong with it? Please help me?

string _search;
private void txtSearchBox_TextChanged(object sender, TextChangedEventArgs e)
{
    _search = txtSearchBox.Text;
}

SQLiteConnection sqlite_conn = new SQLiteConnection("Data Source = music.db");
SQLiteCommand sqlite_cmd;

private void btn_search_Click(object sender, RoutedEventArgs e)
{
    sqlite_conn.Open();
    sqlite_cmd = sqlite_conn.CreateCommand();
    sqlite_cmd.CommandText = "select Title, ArtistName, AlbumName from Song,Artist,Album where (Song.Title=@title) and (Song.AlbumID=Album.AlbumID) and (Song.ArtistID=Artist.ArtistID)";
    
    sqlite_cmd.Parameters.Add("@title", DbType.String, -1);
    sqlite_cmd.Parameters["@title"].Value = _search;
    
    DataSet dataSet = new DataSet();
    SQLiteDataAdapter dataAdapter = new SQLiteDataAdapter(sqlite_cmd.CommandText, sqlite_conn);
    
    dataAdapter.Fill(dataSet); /*****************/
    datagrid.ItemsSource = dataSet.Tables[0].DefaultView;
    datagrid.CanUserAddRows = false;
    datagrid.CanUserDeleteRows = false;
    sqlite_conn.Close();
}

推荐答案

由于您正在使用CommandText而不是SQLiteCommand对象构造SQLiteDataAdaptor，因此发生错误。 CommandText不包含SQLiteParameter对象 - 只是它在字符串中的占位符。



更改

The error is occurring because you are constructing the SQLiteDataAdaptor with the CommandText, rather than the SQLiteCommand object. The CommandText does not contain the SQLiteParameter object - just its placeholder in the string.

Changing

SQLiteDataAdapter dataAdapter = new SQLiteDataAdapter(sqlite_cmd.CommandText, sqlite_conn);

to

to

SQLiteDataAdapter dataAdapter = new SQLiteDataAdapter(sqlite_cmd, sqlite_conn);

应该修复问题。

should fix the issue.

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