Question

Let’s say i check if

 $strig = "how can i do this";

already exists in my database with all words order options?
Like:
“how i can do this”
or
“i do this can how”
…
…

my database looks like:

 id    string
  1    how can i do this
  2    hello how are you
  3    how i can do this world
  4    another title
 etc   etc

Thanks

Answer 1

This is a tricky problem if you want to fix this in sql only, but that aside:

As @er.anuragjain says, you can do a query with LIKE %word%, but you would also get a hit on your example ‘3’.

So if you have a query like this:

SELECT * FROM table WHERE
     column LIKE '%how%' 
AND  column LIKE '%can%'
AND  column LIKE '%i%'
AND  column LIKE '%do%'
AND  column LIKE '%this%'

Then you also get number 3. So you need to check if there are no other words. You can do this by checking the word count (if you have 5 words and all of your words are in there, you are done.).

Checking wordcount is not trivial, but there is a trick. From several sources*:

SELECT LENGTH(total_words) - LENGTH(REPLACE(total_words, ' ', ''))+1
FROM tbl_test;

should do the trick. So check the LIKE‘s, and check the wordcount, and you’re done. But I’m not really sure this is a pretty sollution 🙂

• http://www.webtechquery.com/index.php/2010/03/count-number-of-words-in-mysql-mysql-words-count/
  and http://www.mwasif.com/2008/12/count-number-of-words-in-a-mysql-column/
  (random google hits 🙂 )