PHP库进行模糊搜索？

Question

I'm looking for a PHP library that will allow users to basically enter commands to run by using real english. Basically I want a user to be able to do something like:

Please search for all users in Europe which would equate to a select * where users = 'Europe'

Or another example of my intentions:

Lookup (Find) the email address for John Smith

Note: It would also be nice if you could say for John Smith, Jane Smith, and John Doe

Ideally I'd like this library if it exists to be scalable so I can program in what needs to happen once certain things show up like find,email or search,users

Is anyone aware of a PHP Library that can do something like the above?

Answer 1

As far as I know, currently there aren't libraries for doing a search based on natural language queries, neither in PHP nor in any other programming language (I assume you can't use IBM Watson :) ).

I think the feasible approaches are a grammar-based parser and fuzzy search :

Using a parser generator like Jison you can parse and "understand" on the user browser all the statements corresponding to a generative grammar, sending to the server just the generated query or an intermediate representation.

It's better than a PHP parser because the user can have an immediate feedback while typing and it's less frustrating than submit a form and get an error. The query interpretation in this case would be 99% correct, but in many case a perfectly right (from the human point of view) query will be rejected because not be foreseen by the grammar.

In the other case, you can do some pre-processing, like removing stop words, making text lowercase, stemming and so on, then search with a full text search engine (Lucene is probably the most powerful, but it's in Java). PostgreSQL support it and also MySQL has some full text search capabilities. It's also possible to build a primitive engine based on a basic RDBMS using index and tokenizing text on whitespaces and punctuation.

Which way depends on how diversified and noisy is your data and various the expected query. You can also try to implement an hybrid approach, that is, parse the text using the grammar and whether it fails use a full text search.