title: Insert into table if a field value do not already exist
body: <p>I want to insert values to a row in my customer table if the Name value I'm providing do not already exist,
  After some searching I used this sql query to do it and it does not work :(</p>
  
  <pre><code>IF NOT EXISTS (SELECT Name FROM customer WHERE Name = 'Riyafa') 
  INSERT INTO customer (`Name`, `Address`, `ContactNo`,`Total_amout`)
                        VALUES ('Riyafa', 'ABC', '555','1000');
  </code></pre>
  
  <p>Please instruct me why that is incorrect.</p>