title: Being sensitive to uppercase and lowercase in mysql query
body: <p>I have a capcha code for example i have in database table it as:<code>Nag14I</code> .if i put it as:<code>nag14i</code> in following mysql query i have a output:</p>
  
  <pre><code>$query = "SELECT * FROM captcha WHERE word = 'nag14i' AND captcha_time &gt; '$expiration'";
  print_r($query); //[num_rows] =&gt; 1
  </code></pre>
  
  <p>I have in out put as:</p>
  
  <pre><code>word = Nag14I =&gt; [num_rows] =&gt; 1 
  word = nag14I =&gt; [num_rows] =&gt; 0 
  word = Nag14i =&gt; [num_rows] =&gt; 0 
  word = nag14i =&gt; [num_rows] =&gt; 0
  </code></pre>
  
  <p>How can match all letters if is uppercase or lowercase by mysql query?</p>