查询工作在访问，但不是在我的程序.为什么

本文关键字：我的 程序 为什么 工作 访问 查询 | 更新日期: 2023-09-27 18:02:58

我在应用程序中设置了这个查询，以便通过数据库进行搜索。我把这个查询进入访问，它工作得很好。然而，当我把它放入程序时，表有0个条目。你能帮帮我吗?

private async Task FilterDB()
        {
            List<string> Filter = new List<string>();
            if (CardNameCheck.IsChecked == true)
                Filter.Add("*" + CardNameBox.Text + "*");
            else
                Filter.Add("*");
            if (CardExpanCheck.IsChecked == true)
                Filter.Add("*" + CardExpanBox.Text + "*");
            else
                Filter.Add("*");
                OleDbConnection DBCon = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + Properties.Settings.Default.DatabaseLocation);
                await DBCon.OpenAsync();
                OleDbDataAdapter CardDA = new OleDbDataAdapter("SELECT * FROM Cards WHERE Name like '" + Filter[0] + "' and Expansion like '" + Filter[1] + "'", DBCon);
                DataSet CardDS = new DataSet();
                CardDA.Fill(CardDS);
                DBCon.Close();

查询工作在访问，但不是在我的程序.为什么

我试了一下你的代码并修改了一下。适用于我的Access2003 .mdb格式。

OleDbConnection DBCon = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=(k:'mydatabases'mydatabase.mdb");
DBCon.Open();  
// Create a select Command - you need System.Data.OleDb and System.Data for this
OleDbCommand selectCommand = new OleDbCommand();
// define the CommandText with two parameters @Filter1 and @Filter2
selectCommand.CommandText = "SELECT * FROM Cards WHERE Name like @Filter1 and Expansion like @Filter2";
selectCommand.Connection = DBCon;
// Create two string / VarChar Parameters - 
// the following is a standard I commonly use 
// for string/varchar; you might also use OleDbType.NVarChar
OleDbParameter param01 = new OleDbParameter();
param01.ParameterName = "Filter1";
param01.DbType = DbType.AnsiString;
param01.OleDbType = OleDbType.VarChar;
param01.SourceVersion = DataRowVersion.Current;
param01.SourceColumn = "Name";
// provide them with values - I used text boxes for input
// use '%' for like statement - if no parameter provided use single '%' only
if (txtFilter1.Text.ToString().Equals(""))
{
    param01.Value = '%';
}
else
{ 
    param01.Value = '%' + txtFilter1.Text.ToString() + '%'; 
}
// add the parameter to the SelectCommand
selectCommand.Parameters.Add(param01);
// same goes for the second parameter
OleDbParameter param02 = new OleDbParameter();
param02.ParameterName = "Filter2";
param02.DbType = DbType.AnsiString;
param02.OleDbType = OleDbType.VarChar;
param02.SourceVersion = DataRowVersion.Current;
param02.SourceColumn = "Expansion";
if (txtFilter2.Text.ToString().Equals(""))
{
    param02.Value = '%';
}
    else
{
    param02.Value = '%' + txtFilter2.Text.ToString() + '%';
}
selectCommand.Parameters.Add(param02);
OleDbDataAdapter CardDA = new OleDbDataAdapter();
// tell the DataAdapter to use a SelectCommand
CardDA.SelectCommand = selectCommand;
CardDA.GetFillParameters();   // actually not sure if you need this but does no harm either
DataSet CardDS = new DataSet();
CardDA.Fill(CardDS, "TargetTable");
DBCon.Close();
foreach(DataRow row in CardDS.Tables["TargetTable"].Rows)
{
    // do something ;
}

祝你好运!

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