Lots of ereg_replace 's

joey3002

$text = ereg_replace("(","[",$text);
$text = ereg_replace(")","]",$text);
$text = ereg_replace("[[","[",$text);
$text = ereg_replace("]]","]",$text);
$text = ereg_replace("_"," ",$text);

I have another 20 to 30.

I have over 175,000 records in my database. How much do reg_replace slow down the query?

Also, is there a better way to do alot of replace's like this?

Thanks Guys

jernhenrik

how much it slows down i have no idea??

$arr1= array ("/=74/", "/=F8/", "/=E5/", "/(\015\012)|(\015)|(\012)/", "/=20/");
$arr2= array ("æ","ø","å", " ", " ");
$text=preg_replace($arr1, $arr2, $text);

this is preg_replace, but it should be the same, its off course just a 'neater' way of doing it than line by line.

hth

joey3002

your replacements are not mine i take it?

any chance for a sample of like 2 of my lines... what it would look like?

thanks again

jernhenrik

$arr1= array("(", ")", "[[", "]]", "_");
$arr2=array("[", "]", "[", "]", " ");
$text=ereg_replace($arr1, $arr2, $text);

just fill up arrays in correct order, so that what is in arr1[0] corrosponds to what must be substituted with in $arr2[0]..and so on

joey3002

NICE!! thanks, do you think this will speed things up?

I have alot of replaces like this... i have to think i might be able to shed .25 of a second. My query is running at about .70, I want to get that down to like .25

I did run explain select blah,blah blah

and i have the index on the on where clause.

jernhenrik

pfff....u are asking the wrong guy....but my first intuition is, that as long as u stay away from joins 😉 when dealing with mysql queries, and u have indexed ur db according to the fields u use for searching u can't really do anything more on the query itself.
How u treat the data afterwards by replacing and so on, i have no idea whatsoever how much it will mean for ur speed of excecution when u replace using an array 😕

joey3002

i will let you know. I am hoping to do all the replaces tonight as well as

$next = Next

that kind of replacements too

i will give ya an update later.

liljim

In your example, you're using straight characters (or sets of characters, like brackets preceeded by a backslash) in your replacements. For replacements in strings like this, you're almost certainly always better off using str_replace(). Use the preg/ereg functions when you're wanting to match and / or replace patterns.

str_replace can take arrays as arguments, too. Just for the record, from the manual entry:

This function returns a string or an array with all occurences of search in subject replaced with the given replace value. If you don't need fancy replacing rules, you should always use this function instead of ereg_replace() or preg_replace().

intenz

Do NOT use REGEXP, it slows things up when you CAN use str_replace.
Try...

$arrObj1 = array('(',')','[[',']]','_');
$arrObj2 = array('[',']','<b>[</b>','<b>]</b>',' ');
$strText = str_replace($arrObj1,$arrObj2,$strText);