How to Print a Joomla Query from PHP

So you’re working on a new extension, or in the Joomla core itself, and you’re using a DatabaseQuery object, and you want to print the query object as a SQL string. How do you do that?

Well, assuming the name of the object is $query, there are 4 ways to do this:

  1. echo $query->__toString();: This statement prints the SQL string out of the $query object, but there’s a catch: the SQL string has the database prefix as #__.
  2. echo($query);: This simple code is equivalent to the previous one, since (in PHP) printing an object as a string is really calling the __toString() method of that object.

  3. echo($query->dump());: This code is equivalent to the first and second code, with one minor difference: the #__ is replaced with the actual database (or table) prefix (or alias). This is the best method to print the SQL string out of the DatabaseQuery object.

  4. str_replace('#__', $query->db->getPrefix(), $query): This code yields the exact output as the previous one – this is normal, because the dump method simply consists of this str_replace code.

Note that all 4 methods work in Joomla 2.5, 3, 4, and 5 – it’s probably worth to mention though that the implementation of the __toString method (which is the base method used by all the other methods) differs between Joomla 2.5/3 and Joomla 4/5.

So, which method is the most used to print a SQL query? One would think the 3rd method, but, from our observation, it’s actually the first one – which is odd, because the second method is the simplest, and the third method is the best (as it prints the SQL command with the database prefix). What’s even more odd is that the third method is deprecated since Joomla 4 with no replacement (according to the documentation). We’re not sure why is that exactly.

We hope you found this short post useful – and if you need help with anything Joomla, including development, then please contact us. Our fees are right, our Joomla expertise is unquestioned, and our work is very clean!

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