Question

I dont know what’s wrong with this PHP code:

$sql = "CREATE TABLE test (
 id mediumint(9) unsigned NOT NULL auto_increment,
 filenames text NOT NULL,
 meta longtext,
 added_date datetime NOT NULL default '0000-00-00 00:00:00',
 PRIMARY KEY  (id)
)";
var_export(explode("\n",$sql));

The code above basically explode the string in $sql with newline char (‘\n’) and then output it using var_export. I have some PHP tests file to worked with the code but not all of them displaying what I hope it would be:

array ( 0 => 'CREATE TABLE test ( ', 
        1 => ' id mediumint(9) unsigned NOT NULL auto_increment, ', 
        2 => ' filenames text NOT NULL, ', 
        3 => ' meta longtext, ', 
        4 => ' added_date datetime NOT NULL default \'0000-00-00 00:00:00\', ', 
        5 => ' PRIMARY KEY (id) ', 6 => ') ;', 
)

some diplaying this instead:

array ( 0 => 'CREATE TABLE test ( id mediumint(9) unsigned NOT NULL auto_increment, filenames text NOT NULL, meta longtext, added_date datetime NOT NULL default \'0000-00-00 00:00:00\', PRIMARY KEY (id) ) ;', )

notice the difference? the second one displaying it as there are no newline to exploding the string. I don’t get what’s happening here. Anyone knows something maybe?

Answer 1

You need to be flexible with what a line feed looks like. You can make a flexible explode:

preg_split("/[\r\n]+/", $sql)

… or you can normalize line feeds to the format of your choice:

$sql = strtr($sql, array(
    "\r\n" => "\n",
    "\r" => "\n",
));
explode("\n",$sql)

It’s also worth noting that MySQL offers several SHOW statements that allow you to fetch most useful piece of data from table definitions. Parsing the SHOW CREATE TABLE output is often not necessary:

http://dev.mysql.com/doc/refman/5.1/en/show.html