The CTlib API supports placeholders (and I've even added that support to Sybase::CTlib).

But the support is in the server - this means that some code examples given in the DBI man page fail miserably. In particular, perldoc DBI mentions that to include NULL values from placeholders in a WHERE clause you need to do something like this: 

... WHERE (product_code = ? OR (? IS NULL AND product_code IS NULL))

[download]
This will fail miserably with Sybase, because Sybase will attempt to find the datatype of each placeholder by matching it with a column. The ? is null doesn't map to any column name, so Sybase returns an error.

Whether this is a behavior that is valid or not is maybe debatable, but the great advantage is that Sybase knows the datatype of each placeholder when you execute a prepared statement - no need to bind them with a specific datatype (and in fact using bind_param() with a datatype will ignore the hint).

Cross-platform APIs are non-trivial, and cross-platform programming with databases is even more so because various forms of SQL syntax can have a huge impact on performance.

Michael

In reply to Re: Re: DBI prepare_cached and DBD::Sybase by mpeppler
in thread DBI prepare_cached and DBD::Sybase by mpeppler

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