How hard is it to incorporate full text search with SQL Server?

Question

I am building a C#/ASP.NET app with an SQL backend. I am on deadline and finishing up my pages, out of left field one of my designers incorporated a full text search on one

Answer 1

First off, you need to enabled Full text Searching indexing on the production servers, so if thats not in scope, your not going to want to go with this.

However, if that's already ready to go, full text searching is relatively simple.

T-SQL has 4 predicates used for full text search:

• FREETEXT
• FREETEXTTABLE
• CONTAINS
• CONTAINSTABLE

FREETEXT is the simplest, and can be done like this:

SELECT UserName
FROM Tbl_Users
WHERE FREETEXT (UserName, 'bob' )

Results:

JimBob
Little Bobby Tables

FREETEXTTABLE works the same as FreeTEXT, except it returns the results as a table.

The real power of T-SQL's full text search comes from the CONTAINS (and CONTAINSTABLE) predicate...This one is huge, so I'll just paste its usage in:

CONTAINS
    ( { column | * } , '< contains_search_condition >' 
    ) 

< contains_search_condition > ::= 
        { < simple_term > 
        | < prefix_term > 
        | < generation_term > 
        | < proximity_term > 
        | < weighted_term > 
        } 
        | { ( < contains_search_condition > ) 
        { AND | AND NOT | OR } < contains_search_condition > [ ...n ] 
        } 

< simple_term > ::= 
    word | " phrase "

< prefix term > ::= 
    { "word * " | "phrase * " }

< generation_term > ::= 
    FORMSOF ( INFLECTIONAL , < simple_term > [ ,...n ] ) 

< proximity_term > ::= 
    { < simple_term > | < prefix_term > } 
    { { NEAR | ~ } { < simple_term > | < prefix_term > } } [ ...n ] 

< weighted_term > ::= 
    ISABOUT 
        ( { { 
                < simple_term > 
                | < prefix_term > 
                | < generation_term > 
                | < proximity_term > 
                } 
            [ WEIGHT ( weight_value ) ] 
            } [ ,...n ] 
        ) 

This means you can write queries such as:

SELECT UserName
FROM Tbl_Users
WHERE CONTAINS(UserName, '"little*" NEAR tables')

Results:

Little Bobby Tables

Good luck :)