title: How to retrieve unique rows based on column value combinations?
body: <p>I have a table <code>mytable</code> like below;</p>
  
  <pre><code>╔═════════╦══════╦═════╗
  ║ product ║ tag  ║ lot ║
  ╠═════════╬══════╬═════╣
  ║ 1111    ║ 101  ║ 2   ║ 
  ║ 1111    ║ 102  ║ 5   ║ 
  ║ 2222    ║ 103  ║ 6   ║ 
  ║ 3333    ║ 104  ║ 2   ║  
  ║ 4444    ║ 101  ║ 2   ║ 
  ║ 5555    ║ 101  ║ 2   ║ 
  ║ 5555    ║ 102  ║ 5   ║ 
  ║ 6666    ║ 102  ║ 2   ║ 
  ║ 6666    ║ 103  ║ 5   ║
  ║ 7777    ║ 101  ║ 2   ║ 
  ║ 7777    ║ 102  ║ 5   ║ 
  ║ 7777    ║ 103  ║ 6   ║ 
  ║ 8888    ║ 101  ║ 1   ║ 
  ║ 8888    ║ 102  ║ 3   ║ 
  ║ 8888    ║ 103  ║ 5   ║ 
  ╚═════════╩══════╩═════╝
  </code></pre>
  
  <p>I have the input <code>101</code>,<code>102</code>. I want the output like;</p>
  
  <pre><code>2,5
  3,5
  </code></pre>
  
  <p>which means, in the table, it will look for combinations <code>101,102</code>, and returns the <strong>exact same combinations</strong> with <strong>different lot number</strong>. Along with this, I want to avoid duplicate rows. Here <code>1111</code> and <code>5555</code> has same tags with same corresponding lot numbers to <code>tag</code>s, so I want only one row instead of 2 rows. Even though, <code>8888</code> has tags <code>101</code> and <code>102</code> with different <code>lot</code>s, it cannot be considered for listing , since it includes tag <code>103</code> in addition. Which means, I want products with exact <code>101, 102</code> combination. In short, I dont want products with any extra tags, and i dont want anything with missing tags.</p>
  
  <p>How can I achieve this?</p>