RCurtis Posted November 4, 2013 Share Posted November 4, 2013 Very much a noob here...please bear with me! I have a MySQL table that has a particular column that contains data that "looks" like CSV data. Example: We'll say that the column name is "class" record 1 - 1,3,5,2,8,10 record 2 - 6,4,8,10,2,1 I need to read through each record (I know how to do this...) read each field value into a string (can do this...) Here is my challenge: Once I have the data read into a string value I need to be able to "remove" a given value from the string and write it back. In other words, let's assume I want to remove "1": Data would become: record 1 - 3,5,2,8,10 record 2 - 6,4,8,10,2 Note that any of the field values could have a "1" *and* a "10". Simply looking for the "1"s in a string search isn't going to cut it. I am assuming the data needs to be pulled into an array and do some comparing...but my brain is "losing it" here...no clue how to proceed! Can someone point me in a direction? Quote Link to comment https://forums.phpfreaks.com/topic/283590-php-mysql-field-string-manipulation-and-value-replacement/ Share on other sites More sharing options...
DavidAM Posted November 4, 2013 Share Posted November 4, 2013 ... Can someone point me in a direction?Fix your database design! Normalize the table so you do NOT have multiple values in a single column. There should be a parent table and a child table with a one-to-many relationship. Then the "update" you want to do becomes a simple DELETE statement. Otherwise, you will need a query (SELECT), a for loop, explode(), array_search(), implode(), and another query (UPDATE). Quote Link to comment https://forums.phpfreaks.com/topic/283590-php-mysql-field-string-manipulation-and-value-replacement/#findComment-1456912 Share on other sites More sharing options...
RCurtis Posted November 4, 2013 Author Share Posted November 4, 2013 Thanks very much for the quick reply! I wish that I *could* change the database...but it is part of a website CMS that I really can't change. *I* am the one that is (somewhat) going out on a limb and trying to do something behind the scenes. Quote Link to comment https://forums.phpfreaks.com/topic/283590-php-mysql-field-string-manipulation-and-value-replacement/#findComment-1456929 Share on other sites More sharing options...
AbraCadaver Posted November 4, 2013 Share Posted November 4, 2013 Probably an easier pattern, but: $var = preg_replace('/,1\b|\b1,/', '', $var); Quote Link to comment https://forums.phpfreaks.com/topic/283590-php-mysql-field-string-manipulation-and-value-replacement/#findComment-1456930 Share on other sites More sharing options...
Solution DavidAM Posted November 4, 2013 Solution Share Posted November 4, 2013 Probably an easier pattern, but: $var = preg_replace('/,1\b|\b1,/', '', $var); I'm not sure that will work if "1" is the ONLY value in the column (there's no comma to match). If I were stuck with this data, I would either use the explode/implode sequence: $list = '1,3,5,2,8,10'; $list = explode(',', $list); if (($sub = array_search(1, $list)) !== false) unset($list[$sub]); $list = implode(',', $list); OR add a comma to the beginning and the end of the string and then replace ",1," with ",", and then trim the leading/trailing commas: $list = '1,3,5,2,8,10'; $newlist = ',' . $list . ','; $newlist = str_replace(',1,', ',', $newlist); $newlist = trim($newlist, ','); Quote Link to comment https://forums.phpfreaks.com/topic/283590-php-mysql-field-string-manipulation-and-value-replacement/#findComment-1456953 Share on other sites More sharing options...
RCurtis Posted November 5, 2013 Author Share Posted November 5, 2013 DavidAM...The explode/implode snippet worked perfectly!! Thank you so much. I had a feeling it was going to involve explode...but I've never used implode before and I certainly don't think I would have ever gotten the entire if statement down on my own...Thanks! Quote Link to comment https://forums.phpfreaks.com/topic/283590-php-mysql-field-string-manipulation-and-value-replacement/#findComment-1456985 Share on other sites More sharing options...
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