title: mysql datatype for telephone number and address
body: <p>I want to input telephone number in a form, including country code, extension</p>
  
  <pre><code>create table if not exists employee(    `   
        country_code_tel   int(11),
        tel_number         int(10),
        extension          int(10),
        mobile             bigint(20)
  );
  </code></pre>
  
  <p>If tel_number is larger than 15 bit, which datatype can I use, I'd better use <code>Bigint(20)</code>?</p>
  
  <pre><code>create table address(
        address           varchar(255),  
        city              varchar(255),
        country           varchar(255),
        post_code         int(11)
  );
  </code></pre>
  
  <p>For example, if I have a country code for Canada I can use +2 or 002. Which is better for processing?  </p>
  
  <p>Thanks for your advice. </p>