Table of Contents for

MySQL in a Nutshell, 2nd Edition

This function executes a statement handle that has been processed with the prepare() method. A value of undef is returned if there’s an error. It returns true if successful, even when the results set is blank or zero. For statements other than SELECT statements, the number of rows affected is returned. Here is an example:

...
my $dbh = DBI->connect ("$data_source","$user","$pwd")

my $pub_year = '1961';
my $genre = 'novel';

my $sql_stmnt = "SELECT title, author 
                 FROM books
                 WHERE pub_year = '$pub_year'
                 AND genre = '$genre'";
my $sth = $dbh->prepare($sql_stmnt);

my $rows_chg = $sth->execute();

while( my($title,$author) = $sth->fetchrow_array()) { 
   print "$title by $author \n";
}

You can use placeholders in the SQL statement (e.g., for $pub_year and $genre) by giving the values with execute():

. . .
my @values = ('1961','novel');

my $sql_stmnt = "SELECT title, author 
                 FROM books
                 WHERE pub_year = ?
                 AND genre = ?";
my $sth = $dbh->prepare($sql_stmnt);

$sth->execute(@values);

while( my($title,$author) = $sth->fetchrow_array()) { 
   print "$title by $author \n";
}

You don’t have to put values into an array for use with this method. You can put the strings inside the parentheses of the function (e.g., $sth->execute($pub_year,$genre);).