Define all table/column names as constants in PHP?

[ywliu]

Hello,

I know there is a kind of practice to define all table and column names, in addition to DB host, DB user , and DB password, as constants in PHP. For example:

define('TB_MEMBER','member');
define('FLD_MEMBERID','memberid');

$sql='SELECT '. FLD_MEMBERID. ' FROM '. TB_MEMBER;

This is a very tiny example. But as the tables grow, there can easily be hundreds of define()s in the code.

I have been looking around to look for any pros and cons to this practice, to no avail. I've been handled a project with more than two hundred of defined table/column constants, which don't make change easier but result in more ugly and messy code and defines.

I personally seldom or never use this approach. I personally think this makes possible db design change a little easier,but with a high price to pay. I'd like to know how you guys think if this practice is good to you.

Thanks for your attention.

Yen-Wei Liu

[Weedpacket]

Here's the question. Is

$sql = 'SELECT '.FLD_MEMBERID.' FROM '.TB_MEMBER;

any easier to read than

$sql = 'SELECT memberid FROM member';

?

The first might be preferable if you had a tendency to rename tables and columns in the database.

ywliu wrote:

I know there is a kind of practice to define all table and column names, in addition to DB host, DB user , and DB password, as constants in PHP.

I've never seen it. More useful is isolating all the database-specific stuff in one place, so that if anything changes with the database, it's only the database-specific portion that has to be updated to match it.

[djjjozsi]

you can make a function for select, then you can use the user friendly field names.