 <p>You cannot cast the value in mysql using float type.</p> <p>The type can use following values:</p> <ul> <li>BINARY[(N)]</li> <li>CHAR[(N)]</li> <li>DATE</li> <li>DATETIME</li> <li>DECIMAL[(M[,D])]</li> <li>SIGNED [INTEGER]</li> <li>TIME</li> <li>UNSIGNED [INTEGER]</li> </ul> <p>So in your case you have to use decimal, e.g:</p> <pre><code>select cast(amount AS DECIMAL(10,2)) as 'float-value' from amounts </code></pre>