Programming the Perl DBI

Name

bind_param_inout

Synopsis

$rc = $sth->bind_param_inout($p_num, \$bind_value, $max_len) ||
die $sth->errstr;
$rv = $sth->bind_param_inout($p_num, \$bind_value, $max_len,
\%attr) || ...
$rv = $sth->bind_param_inout($p_num, \$bind_value, $max_len,
$bind_type) || ...

This method acts like bind_ param , but also enables values to be updated by the statement. The statement is typically a call to a stored procedure. The $bind_value must be passed as a reference to the actual value to be used.

Note that unlike bind_ param, the $bind_value variable is not read when bind_ param_inout is called. Instead, the value in the variable is read at the time execute is called.

The additional $max_len parameter specifies the minimum amount of memory to allocate to $bind_value for the new value. If the value returned from the database is too big to fit, then the execution should fail. If unsure what value to use, pick a generous length, i.e., a length larger than the longest value that would ever be returned. The only cost of using a larger value than needed is wasted memory.

It is expected that few drivers will support this method. The only driver currently known to do so is DBD::Oracle (DBD::ODBC may support it in a future release). Therefore, it should not be used for database-independent applications.

Undefined values or undef are used to indicate null values. See also "Placeholders and Bind Values” for more information.