title: Increment primary key/unique value on column in MySQL
body: <p>My goal is to increment of +7 a primary key value into a table in MySQL db.</p>
  
  <p>Tablename = table, Primary key = id</p>
  
  <p>Example:</p>
  
  <pre><code>id   name   surname
  1    John   Doe
  2    Mary   McCain
  3    Sam    Smith
  4    Roy    Jenson
  </code></pre>
  
  <p>I need to turn it into</p>
  
  <pre><code>id   name   surname
  8    John   Doe
  9    Mary   McCain
  10   Sam    Smith
  11   Roy    Jenson
  </code></pre>
  
  <p>So that I can insert 7 more rows before the existing ones.</p>
  
  <p>I tried: </p>
  
  <pre><code> UPDATE table SET id = id + 7
  </code></pre>
  
  <p>But I get the error:</p>
  
  <pre><code> Failed to execute SQL : SQL UPDATE table SET id = id + 7 failed : Duplicate entry '2' for key 1
  </code></pre>
  
  <p>Honestly I really don't know how to fix this, also because I have more than 122,000 entries in that table and it would take several days if not several weeks to update them one by one by hand.</p>