X/Open SQL data types
The X/Open standards support only a subset of the SQL data types that are specific to HCL Informix®. To conform to the X/Open standards, you must use the X/Open SQL data type constants.
The DESCRIBE statement uses these constants to specify the data type of a column (or a return value) when you compile your Informix® ESQL/C program with the -xopen option.
The X/Open data type constants are defined in the sqlxtype.h header file.