Question

I have a database table with following layout, containing 100.000 entries:

id | url 
1  | http://www.foo.com/ZedFe.htm
2  | www.foo.com/tEzqz.htm?q=eee
3  | foo.com/ZeeFg.htm
4  | http://www.foo.com/lkeiO
etc.

I now want to have a third column with the 5-character code of every url, but as you see not every url is formatted in the same way.
In php, I would do it like this:

$id = substr($url, strpos($url,'foo.com/') + 8, 5);

Can this be done in MySQL, using the LOCATE() and SUBSTR() functions?

Answer 1

Another I think more common point of view is that string operations are a perfectly legitimate part of SQL and using them for the purpose you describe is quite appropriate.

Here’s the basic list – you’ll find what you are familiar with – use CONCAT because there’s no equivalent operator.

http://dev.mysql.com/doc/refman/5.5/en/string-functions.html

I found many examples when I googled “mysql sql parse url”. One interesting sample:

SUBSTRING_INDEX(SUBSTRING_INDEX(SUBSTRING_INDEX(TRIM(LEADING
"https://" FROM TRIM(LEADING "http://" FROM TRIM(url))), "/", 1), ":",
1), ".", IF(url LIKE "%.org.__%" OR url LIKE "%.net.__%" OR url LIKE
"%.com.__%" OR url LIKE "%.__.us%" OR url LIKE "%.co.__%" OR url LIKE
"%.__.uk%", -3, -2) )