How to create more complex Lucene query strings?

Question

This question is a spin-off from this question. My inquiry is two-fold, but because both are related I think it is a good idea to put them together.

• How to programmatically create queries. I know I could start creating strings and get that string parsed with the query parser. But as I gather bits and pieces of information from other resources, there is a programattical way to do this.
• What are the syntax rules for the Lucene queries?

--EDIT--

I'll give a requirement example for a query I would like to make:
Say I have 5 fields:

1. First Name
2. Last Name
3. Age
4. Address
5. Everything

All fields are optional, the last field should search over all the other fields. I go over every field and see if it's IsNullOrEmpty(). If it's not, I would like to append a part of my query so it adds the relevant search part.
First name and last name should be exact matches and have more weight then the other fields. Age is a string and should exact match. Address can varry in order. Everything can also varry in order.

How should I go about this?

Answer 1

The easiest way to programmatically creating queries is by building a query string and use the Query Parser to generate the query.

Syntax for Lucene Query Parser can be found here.

Answer 2

Use the BooleanQuery class to compose query objects. Create one of these and add() other Query objects to it to create a larger, disjunctive query:

• BooleanQuery q = new BooleanQuery();
• q.add(qFirstName, Occur.SHOULD);
• q.add(qLastName, Occur.SHOULD);
• ...

Atomic queries can be built with the Term and TermQuery classes.

(Links and example are for Lucene Java, but .NET should be similar.)