Question

I have made a small application where i save students data. I installed it on my PC and it worked just fine.

I gave it to one of my friend to install it on his system, however his windows is in German language, he installed the software perfectly, but when he was trying to store the data he got the error for date field.

What he explained me on the phone that it was a language error as when i was storing the data on my computer which is in English language, date time appeared like this:

Now when he installed my app on his computer the Date of birth field was in German Language and so he got an error while mssql insert query.

My question is how to force the application to use the Date time in just English language as a System time and not that the client language date time?

I am using sqlServerCe

EDIT

QueryGrid("INSERT INTO students (p_num, p_name, p_fname, p_dob, p_street, p_zip, p_phone, p_email, p_sex, p_comment, p_fax, p_pic, p_regdate, p_idc) VALUES('" + p_num.Text + "', '" + p_name.Text + "', '" + p_fname.Text + "', '" + p_dob.Value + "', '" + p_street.Text + "', '" + p_zip.Text + "', '" + p_pno.Text + "', '" + p_email.Text + "', '" + gender + "', '" + comment_box.Text + "', '" + p_fno.Text + "', '" + p_num.Text + "', '" + DateTime.Now + "', '" + p_idc.Text + "')")
MessageBox.Show("Student successfully added in database.")

Now in above code p_dob.Value is my date value. and when i use it on my computer it converts the above Monday, October 22, 2012 to 10/22/2012 11:31 AM and saves into database, now on my friends system its in German language, so its unable to convert and save.

Answer 1

As I said in mycomment, you should never write a query concatenating string: use queries with parameters.
Example:

string query = "INSERT INTO mytable (p_num, p_date) SELECT @num,@dt";
using (SqlConnection conn = new SqlConnection("....."))
{
    conn.Open();
    using (SqlCommand cmd = new SqlCommand(query, conn))
    {
        cmd.Parameters.AddWithValue("num", 1);
        cmd.Parameters.AddWithValue("dt", DateTime.Today);

        cmd.ExecuteNonQuery();
    }
    conn.Close();
}

Naturally this is only part of the code, but should give you an idea.
Concatenating strings can lead you to many troubles, not only with dates but with doubles too.

In general: write queries using params to avoid problems with localization (and others).