I don't know how many monks use DBD::Sybase, but I've just been informed of a potentially nasty bug with DBD::Sybase when using placeholders in conjunction with a LIKE clause.

For example: 

use DBI;

my $param = shift;

my $dbh = DBI->connect('dbi:Sybase:database=testdb', 'sa', '');
my $sth = $dbh->prepare("select * from CAL where CAL_DS like ? + '%'")
+;
$sth->execute($param);
while(my $d = $sth->fetch) {
    print "@$d\n";
}

[download]
Assume a CAL table with the following rows: 
 id       CAL_DS              
 -------- --------------------
        1 A                   
        2 AM                  
        3 AMS                 
        4 AMSTEL              
        5 DSTEL

[download]
Running the script with any argument starting with 'A' will return the first 5 rows (so $sth->execute('ABC') and $sth->execute('A') have the same effect).

I've traced this to a bug in the Sybase OpenClient libraries, where the input parameter description returns a parameter length of 1 for this query, even though the CAL column is a varchar(20).

The only work-around that I can think of is to move the '%' character from the SQL string to the parameter (i.e. $sth->execute('AMS%')) which will work as expected, but is not a generic solution for LIKE queries if you always want to have the wildcard in the query.

Michael

In reply to DBD::Sybase bug by mpeppler

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