MySQL fulltext autocomplete search issues

Question

So I have been struggling with FULLTEXT index searches, had a previous question here which was resolved, but it seems for some searches it works ok, and on others it doesn't

As before, looking for games in a games table, has about 25k rows, with the FULLTEXT index on g_name. I also need it to work using autocomplete as well, eg with incomplete search terms

With the search term, I explode it and then loop each iteration, appending a * onto the end eg 'grand* theft* auto* v*'

So here are some sample searches. It outputs the query at the top:

BOOLEAN MODE off, results ok

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BOOLEAN MODE on, results not coming back as expected

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BOOLEAN MODE off, results ok, although unsure how 'Tenchu: Shadow Assassins' is scoring more relevant to other 'assassins creed' games?

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BOOLEAN MODE on, results not showing 'assassins creed iii'

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Autocomplete texting partial word, BOOLEAN MODE off, NO RESULTS?!

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Autocomplete texting partial word, BOOLEAN MODE off, ok results

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Not sure why turning boolean mode on / off is producing such strange results. Its like I need it on for some searches and off for others, but I need a single search query. The scores seem to be just BS figures pulled from nowhere.

Also if I start adding '+' into the mix for non optional words it produces even stranger results. The whole reason I added fulltext was to make things more flexible, and return more useful results, but seems to have made things worse.

So my question , how do I make it return useful results every time, regardless of the nuances of that particular search term / game, and if its a partial search, or the full term. Ideally similar to how http://www.metacritic.com/ do it (top right search box)

Answer 1

One course project I taught covers this topic: https://grape.ics.uci.edu/wiki/public/wiki/cs122b-2012-spring-project4#Requirement2 Solution: https://grape.ics.uci.edu/wiki/public/wiki/cs122b-2012-spring-mysql-fulltext Pay attention to the following examples:

Prefix Search: SELECT entryID FROM ft WHERE MATCH (entry) AGAINST ('grad*' IN BOOLEAN MODE);

Boolean Searches: SELECT entryID FROM ft WHERE MATCH (entry) AGAINST ('+graduate -michigan' IN BOOLEAN MODE);

This approach works, but is slow and has poor ranking.