我使用C＃插入数据以访问2000-2003文件格式数据库。当我有一个包含2个字段的数据库时，查询工作正常，但是当有更多字段时，它不起作用。
我有两个相同的代码，我无法找到问题。
using System.Data.OleDb; // By using this namespace I can connect to the Access Database.
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
private OleDbConnection myconn;
public Form1()
{
InitializeComponent();
myconn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\leelakrishnan\Desktop\NewManageContacts.mdb");
}
private void Form1_Load(object sender, EventArgs e)
{
// TODO: This line of code loads data into the 'newManageContactsDataSet.Contacts' table. You can move, or remove it, as needed.
// this.contactsTableAdapter.Fill(this.newManageContactsDataSet.Contacts);
// TODO: This line of code loads data into the 'newManageContactsDataSet.Contacts' table. You can move, or remove it, as needed.
this.contactsTableAdapter.Fill(this.newManageContactsDataSet.Contacts);
}
private void button1_Click(object sender, EventArgs e)
{
OleDbCommand cmd = new OleDbCommand();
cmd.CommandType = CommandType.Text;
// string query = "insert into Contacts (fname,lname,llnum,mobnum,e-mail,street,city,country) values ('" + textBox1.Text + "','" + textBox2.Text + "','" + textBox3.Text + "','" + textBox4.Text + "','" + textBox5.Text + "','" + textBox6.Text + "','" + textBox7.Text + "','" + textBox8.Text + "')";
cmd.CommandText = @"insert into Contacts (fname,lname,llnum,mobnum,e-mail,street,city,country) values ('" + textBox1.Text + "','" + textBox2.Text + "','" + textBox3.Text + "','" + textBox4.Text + "','" + textBox5.Text + "','" + textBox6.Text + "','" + textBox7.Text + "','" + textBox8.Text + "')";
cmd.Connection = myconn;
myconn.Open();
cmd.ExecuteNonQuery();
System.Windows.Forms.MessageBox.Show("User Account Succefully Created", "Caption", MessageBoxButtons.OKCancel, MessageBoxIcon.Information);
myconn.Close();
}
private void button2_Click(object sender, EventArgs e)
{
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
textBox4.Text = "";
textBox5.Text = "";
textBox6.Text = "";
textBox7.Text = "";
textBox8.Text = "";
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
}
}
这是只有2个字段的表的代码
public partial class Form1 : Form
{
private OleDbConnection myCon;
public Form1()
{
InitializeComponent();
myCon = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\leelakrishnan\Desktop\Database1.mdb");
}
private void Form1_Load(object sender, EventArgs e)
{
// TODO: This line of code loads data into the 'database1DataSet.Table1' table. You can move, or remove it, as needed.
this.table1TableAdapter.Fill(this.database1DataSet.Table1);
}
private void button1_Click(object sender, EventArgs e)
{
OleDbCommand cmd = new OleDbCommand();
cmd.CommandType = CommandType.Text;
cmd.CommandText = "insert into Table1 (name,fname) values ('" + textBox1.Text + "','" + textBox2.Text + "')";
cmd.Connection = myCon;
myCon.Open();
cmd.ExecuteNonQuery();
System.Windows.Forms.MessageBox.Show("User Account Succefully Created", "Caption", MessageBoxButtons.OKCancel, MessageBoxIcon.Information);
myCon.Close();
}
private void button2_Click(object sender, EventArgs e)
{
textBox1.Text = "";
textBox2.Text = "";
}
}
答案 0 :(得分：5)
您尝试插入的额外字段可能具有不容易连接到有效SQL语句的值。例如：
string field1 = "meh";
string field2 = "whatever";
string field3 = "'Ahoy!' bellowed the sailor.";
var cmd = new SqlCommand(
"INSERT INTO blah (x, y, z) VALUES ('" + field1 + "', '" + field2 + "', '" + field3 + '")");
想象一下，在给定上述输入的情况下，连接的SQL会是什么样子。
更糟糕的是，想象一下，如果有人在你的表单中输入了这个SQL，那么你将执行它：
field3 = "Bobby'); DROP TABLE Users; -- ";
通过cmd.Parameters.Add或AddRange使用参数化查询（描述为here）。因此可以推荐上述例子：
var cmd = new SqlCommand("INSERT INTO blah (x, y, z) VALUES (@x, @y, @z)");
cmd.Parameters.AddRange(new[] {
new SqlParameter("@x", field1),
new SqlParameter("@y", field2),
new SqlParameter("@z", field2)
});
答案 1 :(得分：1)
如果您正在使用 数据库 ，那么主要是借助try-catch block语句，这将有助于您指导代码。在这里，我向您展示如何使用按钮单击事件在数据库中插入一些值。
private void button2_Click(object sender, EventArgs e)
{
System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection();
conn.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;" +
@"Data source= C:\Users\pir fahim shah\Documents\TravelAgency.accdb";
try
{
conn.Open();
String ticketno=textBox1.Text.ToString();
String Purchaseprice=textBox2.Text.ToString();
String sellprice=textBox3.Text.ToString();
String my_querry = "INSERT INTO Table1(TicketNo,Sellprice,Purchaseprice)VALUES('"+ticketno+"','"+sellprice+"','"+Purchaseprice+"')";
OleDbCommand cmd = new OleDbCommand(my_querry, conn);
cmd.ExecuteNonQuery();
MessageBox.Show("Data saved successfuly...!");
}
catch (Exception ex)
{
MessageBox.Show("Failed due to"+ex.Message);
}
finally
{
conn.Close();
}
答案 2 :(得分：0)
此公共代码：
OleDbConnection con = new OleDbConnection(@"Provider = Microsoft.Jet.OLEDB.4.0; Data Source = C:\Users\Mohammadhoseyn_mehri\Documents\Data.mdb");
这个代码为singup按钮：
try
{
craeteaccount();
else
{
MessageBox.Show("Please re Enter Your PassWord");
}
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
MessageBox.Show("Data saved successfuly...!");
con.Close();
}
这个创建帐户方法的代码：
OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * from Login", con);
con.Open();
String ticketno = textBox2.Text.ToString();
String Purchaseprice = textBox1.Text.ToString();
String my_querry = $"INSERT INTO Login(username,pass)VALUES('{ticketno}','{Purchaseprice}')";
OleDbCommand cmd = new OleDbCommand(my_querry, con);
cmd.ExecuteNonQuery();
答案 3 :(得分：-1)
private void btnSave_Click(object sender, EventArgs e)**
{
OleDbCommand cmd = new OleDbCommand();
cmd.CommandType = CommandType.Text;
cmd.CommandText = @"insert into Personal (P_name, P_add,P_Phone)VALUES('" + txtName.Text + "','" +txtAddress.Text + "','" + txtPhone.Text + "')";
cmd.Connection = con;
con.Open();
cmd.ExecuteNonQuery();
System.Windows.Forms.MessageBox.Show("Recrod Succefully Created");
con.Close();
txtName.Text = "";
txtAddress.Text = "";
txtPhone.Text = "";
}