SQL查询输出不在文本框上查看

Question

我的SQL查询输出没有在我的文本框中查看，当表单加载时它必须自动插入到我的文本框中。我的文本框中唯一的输出是System.Data.SqlClient.SqlCommand

我不知道什么是错误或我的代码丢失。请帮助我，对不起，我只是一个C新手＃

任何类型的反应非常感谢。先谢谢你。

private void EmailGen_Load(object sender, EventArgs e) 
{ 
    connect.Open(); 
    string emailto = "select emailaddress from emails where password = ''"; 
    string emailfr = "select emailaddress from emails where password != null"; 
    SqlCommand emailt = new SqlCommand(emailto, connect); 
    SqlCommand emailf = new SqlCommand(emailfr, connect); 
    emailt.ExecuteNonQuery(); 

    txBEmailRec.Text = emailt.ToString(); 
    txBEmailFr.Text = emailf.ToString(); ; 
    connect.Close(); 

    // TODO: This line of code loads data into the 'kwemDataSet.tblProducts' table. You can move, or remove it, as needed. 
    this.tblProductsTableAdapter.Fill(this.kwemDataSet.tblProducts); 
} 

Answer 1

您应该使用ExecuteScalar();，而不是ExecuteNonQuery();并且还，你的代码似乎缺少执行emailf SqlCommand。

你也可以看到这个reference。

private void EmailGen_Load(object sender, EventArgs e) 
{ 
    connect.Open(); 
    string emailto = "select emailaddress from emails where password = ''"; 
    string emailfr = "select emailaddress from emails where password != null"; 
    SqlCommand emailt = new SqlCommand(emailto, connect); 
    SqlCommand emailf = new SqlCommand(emailfr, connect); 

    txBEmailRec.Text = emailt.ExecuteScalar().ToString(); 
    txBEmailFr.Text = emailf.ExecuteScalar().ToString(); 
    connect.Close(); 

    // TODO: This line of code loads data into the 'kwemDataSet.tblProducts' table. You can move, or remove it, as needed. 
    this.tblProductsTableAdapter.Fill(this.kwemDataSet.tblProducts); 
}