Sounds like you're out of luck:
Null Values
Undefined values, or "undef", can be used to indicate null values.
+ However, care must
be taken in the particular case of trying to use null values to qua
+lify a "SELECT"
statement. Consider:
SELECT description FROM products WHERE product_code = ?
Binding an "undef" (NULL) to the placeholder will not select rows
which have a NULL "product_code"! Refer to the SQL manual for your
+database
engine or any SQL book for the reasons for this. To explicitly sel
+ect
NULLs you have to say ""WHERE product_code IS NULL"" and to make th
+at
general you have to say:
... WHERE (product_code = ? OR (? IS NULL AND product_code IS NUL
+L))
and bind the same value to both placeholders. Sadly, that more gene
+ral syntax
doesn't work for Sybase and MS SQL Server. However on those two ser
+vers
the original ""product_code = ?"" syntax works for binding nulls.
-- DBI
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|