ecpg does not understand enum datatypes.

The complete structure definition has to be listed inside the declare
section of the structure variable for ecpg to be able to understand it.

Variable type bool has to be checked. I never used it so far.

ecpg cannot use pointer variables except [unsigned] char *

There is no exec sql type statement which is the SQL version of a typedef.

There is no exec sql prepare statement.

There is no SQLSTATE
