String or binary data would be truncated, insert to SQL Server table

Question

It's a runtime exception when I try to insert to a table, it was working before I added an update function.

    private void button1_Click(object sender, EventArgs e)
    {
        Random rndID = new Random();
        int id = rndID.Next(100, 1000);

        SqlConnection connection = new SqlConnection(@"Data Source=DESKTOP-IOHHC7K\SQLEXPRESS;Initial Catalog=CityAppDB;Integrated Security=True");

        SqlCommand command = new SqlCommand("insert into UsersTB(User_ID, Full_Name, Email_Address, Phone_Number, Password) 
             values('" + id.ToString() + "','" + textBox2.Text + "','" +
             textBox3.Text + "','" + textBox4.Text + "','" + 
             textBox5.Text + "')", connection);
        command.Connection.Open();

        if ((ISExisted(id)) && (CheckUserFullName(textBox2.Text)) && (IsValidEmail(textBox3.Text)) && (IsValidPhoneNumber(textBox4.Text)) && (IsValidPassword(textBox5.Text)))
        {
            command.ExecuteNonQuery();//String or binary data would be truncated
            MessageBox.Show("Added.");
            ShowAllUsers();
        }
        else
        {
            MessageBox.Show("Something wrong");
        }

        command.Connection.Close();
    }

Answer 1

This error means that you are trying to update a value which is too long for the database column definition.

In your database, check the length of your Full_Name , Email_Address , Phone_Number and Password fields, let's say they are definded as varchar[10] , this error means that you are trying to update their value with a string longer than 10 characters,

Check the length of the values stored in one of your textboxes: textBox2.Text , textBox3.Text , textBox4.Text or textBox5.Text . One of them has a text which is longer than the database schema accepts.

Solution 1 : Increase the columns size in the database.

Solution 2 : Use Textbox.MaxLength to limit the user's input length.

Answer 2

Sole purpose of the error is: your column size is specified lesser than the value you are supplying which can only be known from your table structure.

Again stop passing values using string concatenation rather use parameterized query to avoid SQL Injection. Use SqlParameter class

Your parameterized INSERT statement should look like

    string query = "insert into UsersTB(User_ID,Full_Name,Email_Address,Phone_Number,Password) values(@User_ID,@Full_Name,@Email_Address,@Phone_Number,@Password)";
    SqlCommand command = new SqlCommand(query, connection);

    command.Parameters.Add("@User_ID",id.ToString());
    command.Parameters.Add("@Full_Name",textBox2.Text);
    command.Parameters.Add("@Email_Address",textBox3.Text);
    command.Parameters.Add("@Phone_Number",textBox4.Text);
    command.Parameters.Add("@Password",textBox5.Text);