我正在尝试从C#窗口添加长度,宽度,区域等参数值 应用于PostgreSQL中的表。我是初学者。 我收到以下错误, 后端发送了无法识别的响应类型:e
private void button1_Click(object sender, EventArgs e)
{
int length, breadth;float area;
length=Convert.ToInt32(Length.Text);
breadth = Convert.ToInt32(Breadth.Text);
area = length * breadth;
Area.Text = area.ToString();
string connectionString = "Server=localhost;port=5432;Database=DatabaseName;User Id=postgres;Password=pswd";
NpgsqlConnection dbcon = new NpgsqlConnection(connectionString);
dbcon.Open();
NpgsqlCommand dbcmd = dbcon.CreateCommand();
try
{
dbcmd.Parameters.AddWithValue("@len", length);
dbcmd.Parameters.AddWithValue("@bth", breadth);
dbcmd.Parameters.AddWithValue("@area", area);
dbcmd.CommandText = "INSERT INTO Area(length,breadth,area) VALUES (@len,@bth,@area)";
//dbcmd.CommandText = sql1;
//dbcmd.Parameters.Add("@textBox3.Text", textBox3.Text.Trim());
dbcmd.ExecuteNonQuery();
dbcmd.Dispose();
dbcon.Close();
}
catch (NpgsqlException ex)
{
MessageBox.Show("there is a error");
if (ex.Data == null)
{
throw;
}
else
{
}
}
}