7645 Null or empty full-text predicate

问题

I have a query that ran fine on SQL2005 but moving the database to SQL2008 gives me the error from the title.

The code that is the problem is a call to CONTAINS, CONTAINSTABLE or FREETEXT with an empty parameter. However I'm trying to only call or join when there is a value like such

where (@search_term = '' or (FREETEXT(lst.search_text, @search_term)))

left join containstable (listing_search_text, search_text,  @search_term) ftb on l.listing_id = ftb.[key] 
    and len(@search_term) > 0

However I cannot find any workaround for this to work on SQL2008. Any ideas?

I know I can do dynamic SQL or have a if statement with two different cases (select with FT join, select without FT join. Any better workaround which doesn't require doing this?

回答1:

I found the answer to this today when converting my own database from SQL 2005 to SQL 2008.

Pass "" for your search term and change the @search_term = '' test to be @search_term = '""' SQL server will ignore the double quotes and not throw an error.

For example, the following would actually returns all records in the Users table:

declare  @SearchTerm nvarchar(250)

SET @SearchTerm = '""'

select UserId, U.Description, U.UserName
from dbo.Users U
WHERE ((@SearchTerm = '""') OR CONTAINS( (U.Description, U.UserName), @SearchTerm))

If you are using .Net, you might grab a copy of E. W. Bachtal's FullTextSearch class. His site is very informative: http://ewbi.blogs.com/develops/

回答2:

This solution didn't work for me on SQL 2008. The answer seemed pretty clear and was deemed useful but I would get time outs on a table with 2M records. In fact it locked up a server just running the query in SSMS.

It didn't seem to like the OR in the where clause but I could run the query fine separating the conditions.

I ended up using a UNION successfully as a workaround.

declare  @SearchTerm nvarchar(250)

SET @SearchTerm = '""'

select UserId, U.Description, U.UserName
from dbo.Users U
WHERE ((@SearchTerm = '""') 

UNION 

select UserId, U.Description, U.UserName
from dbo.Users U
WHERE CONTAINS( (U.Description, U.UserName), @SearchTerm))

回答3:

Just ADD Double quotes. You can check for empty string and then add double quotes in it.

Set @search_term = case when @search_term = '' then '""' else @Address End

Here you go -

where (@search_term = '""' or (FREETEXT(lst.search_text, @search_term)))

回答4:

The problem with FTS and the OR operand was fixed in SP2 CU4. The OR condition should run ok without having to UNION if you are on that level or later. We tried a very recent update of SP2 CU8 and FTS works with OR now. Also, searches such as 3.12 which would fail before now work just fine.

来源：https://stackoverflow.com/questions/189765/7645-null-or-empty-full-text-predicate

标签

sql-server

full-text-search