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

<p>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</p>

<pre><code>where (@search_term = '' or (FREETEXT(lst.search_text, @search_term)))
</code></pre>

<p>or</p>

<pre><code>left join containstable (listing_search_text, search_text,  @search_term) ftb on l.listing_id = ftb.[key] 
    and len(@search_term) &gt; 0
</code></pre>

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

<p>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?</p>

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/