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

The error message for "no data" in an exec sql insert select from statement
has to be 100.

sqlwarn[6] should be 'W' if the PRECISION or SCALE value specified in a SET
DESCRIPTOR statement will be ignored.

it would be nice to be able to use :var[:index] as cvariable

support for dynamic SQL with unknown number of variables with DESCRIPTORS

The line numbering is not exact.

What happens to the output variable during read if there was an
indicator-error? 

Add a semantic check level, e.g. check if a table really exists.

Missing statements:
 - exec sql ifdef
 - exec sql allocate
 - exec sql deallocate
 - SQLSTATE
