在c#中执行Oracle查询

本文关键字：Oracle 查询 执行 | 更新日期: 2023-09-27 18:12:03

我理解线程的概念，但一般来说我是新手，所以请原谅我。对不起，如果这是一个愚蠢的问题。

我需要在我的Windows窗体程序运行对Oracle数据库的一些密集查询。虽然这段代码确实可以工作，但程序冻结了，因为查询可能需要一分钟才能运行，而我正在按顺序运行几个查询。我认为创建一个单独的线程，如下所示，可以防止这种情况。我是否需要在线程的创建中指定一些东西，表明只有一定数量的资源应该专用于它?我在谷歌上找到了一些答案，但并没有真正理解它们。

提前感谢您的帮助!

    private void loginButton_Click(object sender, EventArgs e)
    {
        loginStatus.Text = "STATUS: Running...";
        Thread thread1 = new Thread(new ThreadStart(GetLoginData));            
        thread1.Start();
        loginStatus.Text = "STATUS: Ready";
    }
    private void GetLoginData()
    {
        try
        {
            Invoke(new Action(() => loginButton.Enabled = false));
            string LDS01_start = "select count(*) from BBLEARN.AUTH_PROVIDER_LOG where AUTH_PROVIDER_PK1 = 103 ";
            string LDAPS_start = "select count(*) from BBLEARN.AUTH_PROVIDER_LOG where AUTH_PROVIDER_PK1 = 106 ";
            string middle = "and log_date >= '" + GetDate(loginStartDate) + @"' 
                         and log_date < '" + GetDate(loginEndDate) + @"' ";
            string LDS01_0 = LDS01_start + middle + "and event_type = 0";
            string LDS01_1 = LDS01_start + middle + "and event_type = 1";
            string LDS01_2 = LDS01_start + middle + "and event_type = 2";
            string LDS01_5 = LDS01_start + middle + "and event_type = 5";
            string LDS01_6 = LDS01_start + middle + "and event_type = 6";
            string LDAPS_0 = LDAPS_start + middle + "and event_type = 0";
            string LDAPS_1 = LDAPS_start + middle + "and event_type = 1";
            string LDAPS_2 = LDAPS_start + middle + "and event_type = 2";
            string LDAPS_5 = LDAPS_start + middle + "and event_type = 5";
            string LDAPS_6 = LDAPS_start + middle + "and event_type = 6";
            Invoke(new Action(() => GetData(LDS01_0, LDS01_LB0)));
            Invoke(new Action(() => GetData(LDS01_1, LDS01_LB1)));
            Invoke(new Action(() => GetData(LDS01_2, LDS01_LB2)));
            Invoke(new Action(() => GetData(LDS01_5, LDS01_LB5)));
            Invoke(new Action(() => GetData(LDS01_6, LDS01_LB6)));
            Invoke(new Action(() => GetData(LDAPS_0, LDAPS_LB0)));
            Invoke(new Action(() => GetData(LDAPS_1, LDAPS_LB1)));
            Invoke(new Action(() => GetData(LDAPS_2, LDAPS_LB2)));
            Invoke(new Action(() => GetData(LDAPS_5, LDAPS_LB5)));
            Invoke(new Action(() => GetData(LDAPS_6, LDAPS_LB6)));
            Invoke(new Action(() => loginButton.Enabled = true));
            loginStatus.Text = "STATUS: Ready";
        }
        catch (Exception e)
        {
            Debug.WriteLine(e);
        }
    }
    private void GetData(string selectCommand, Label label)
    {
        //open the connection
        OracleConnection conn = new OracleConnection(connectString);
        conn.Open();
        //define the command
        selectCommand = selectCommand.Replace(Environment.NewLine, " ");
        OracleDataAdapter dataAdapter = new OracleDataAdapter(selectCommand, conn);
        OracleCommandBuilder commandBuilder = new OracleCommandBuilder(dataAdapter);
        //run the command
        DataTable table = new DataTable();
        table.Locale = System.Globalization.CultureInfo.InvariantCulture;
        dataAdapter.Fill(table);
        //pull the result
        label.Text = table.Rows[0][0].ToString();
        //close the connection
        conn.Close();
    }

在c#中执行Oracle查询

你是invoking的GetData()方法，调用使用UI线程，GetData()方法是反对DB，它需要时间，所以你的屏幕锁定。你只需要调用UI更改，然后Thread off DB调用，在完成后调用UI线程来启用按钮等…

更改GetLoginData()中的呼叫:

Invoke(new Action(() => GetData(LDS01_0, LDS01_LB0)));

: 

GetData(LDS01_0, LDS01_LB0);

将GetData()改为:

private void GetData(string selectCommand, Label label)
{
    //open the connection
    OracleConnection conn = new OracleConnection(connectString);
    conn.Open();
    //define the command
    selectCommand = selectCommand.Replace(Environment.NewLine, " ");
    OracleDataAdapter dataAdapter = new OracleDataAdapter(selectCommand, conn);
    OracleCommandBuilder commandBuilder = new OracleCommandBuilder(dataAdapter);
    //run the command
    DataTable table = new DataTable();
    table.Locale = System.Globalization.CultureInfo.InvariantCulture;
    dataAdapter.Fill(table);
    //close the connection
    conn.Close();
    Invoke(new Action(() => RenderData(label, table.Rows[0][0].ToString())));

}

创建新的RenderData()方法:

private void RenderData(Label label, string text)
{
    label.Text = text;
}
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