那这样写哪里有错误啊?为什么?
string str = "Data Source=.\\SQLEXPRESS;AttachDbFilename=|DataDirectory|\\Database1.mdf;Integrated Security=True;User Instance=True";
SqlConnection conn = new SqlConnection(str);
string sql = "insert into student(id,name,math,english,chinese) values('" + textBox1.Text + "','" + textBox2.Text + "','" + textBox3.Text + "','" + textBox4.Text + "','" + textBox5.Text + "')";
SqlCommand com = new SqlCommand(sql, con);
con.Open();
com.ExecuteNonQuery();
con.Close();