title: How to match any letter in SQL?
body: <p>I want to return rows where certain fields follow a particular pattern such as whether a particular character in a string is a letter or number. To test it out, I want to return fields where the first letter is any letter. I used this code. </p>
  
  <pre><code>SELECT * FROM sales WHERE `customerfirstname` like '[a-z]%';
  </code></pre>
  
  <p>It returns nothing. So I would think that the criteria is the first character is a letter and then any following characters do not matter.
  The following code works, but limits rows where the first character is an a.</p>
  
  <pre><code>SELECT * FROM sales WHERE `customerfirstname` like 'a%';
  </code></pre>
  
  <p>Am I not understanding pattern matching? Isn't it [a-z] or [A-Z] or [0-9] for any letter or number?
  Also if I wanted to run this test on the second character in a string, wouldn't I use</p>
  
  <pre><code>SELECT * FROM `sales` WHERE `customerfirstname` like '_[a-z]%' 
  </code></pre>
  
  <p>This is for SQL and MySQL. I am doing this in phpmyadmin.</p>