How to dynamically create object properties from an array in Javascript?

Is storing the name fields as a representation for a table identifier in either a PHP associative array, or in a Javascript object (client) a viable alternative for making an extra join in MySQL?

• This is a question that I have wondered about for quite some time. When I need to make a query that is for example as follows: SELECT o.business_id, b.business_name, b.category  FROM owner_tbl o  INNER JOIN business_tbl b WHERE o.user_id = 1 Imagine that I need to display the name of the business category (defined in the business_tbl) in Javascript at the client, and I know upfront that the number of categories will not change quickly. I can prevent making an extra join with the category_tbl by storing the category names either: In an associative array in PHP; In an object in Javascript. Would you consider this to be bad practice? This type of situations often occurs: where you make a join, just to retrieve one 'name' field. Is there any alternative way that avoids making a join to speed up the retrieval?

• Answer:

  On the server side, if you can avoid running the SQL query entirely, storing the results in $_SESSION or in a temporary file using perhaps <?php file_put_contents("./datafiles/query1.dat",serialize($myarray),LOCK_EX); // and $myarray = unserialize(file_get_contents("./datafiles/query1.dat")); ?> should gain a bit of speed. You can use filemtime to read when the file was last modified, in order to find out when the file is too old. <?php $filedate = filemtime("./datafiles/query1.dat"); echo "File changed ".date("F d Y H:i:s.", $filedate).", that was ".((now()-$filedate)/60/60)." hours ago."; ?> But if you can not avoid calling the query entirely, a join should be faster unless you are reading/writing to a data file that you need to use anyway. On the client side, you can use window.localStorage (https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Storage) to cache more or less unchanging data. In this case you are simply unloading the job to the client, boosting your own speed a tiny, tiny bit. This is however not very compatible since not all browsers support it, and not all users have JavaScript support turned on.