LOAD and UNLOAD instructions
The LOAD and UNLOAD instructions can produce different
data formats depending on the database server type.
When executing the LOAD and UNLOAD instruction from a BDL
program, SQL commands are not sent as is to the database server.
In fact, the Genero BDL runtime system implements the LOAD and
UNLOAD instructions, using basic INSERT (for
LOAD) or SELECT (for UNLOAD) SQL commands.
With this implementation, the LOAD and UNLOAD instruction can
be supported with various database servers.
However, LOAD and UNLOAD require the description of the column
types in order to work.
Since each database has its own set of SQL data types, you must pay attention to the BDL type that results from the native database column type.
Depending on the native data type, data formatting may be different from Informix®.
DATE column, the
LOAD and UNLOAD instruction will use the date/time format
YYYY-MM-DD hh:mm:ss. Since the native Oracle DATE type can be used
to store both Informix
DATE or DATETIME YEAR TO SECOND values, and as
LOAD / UNLOAD need to make date/time to string conversions when
reading from or writing to unload files, it is not possible to select one of the Informix/BDL native
date type formats.DATE, the date values will use the
DBDATE format setting.| Database Server Type | LOAD/UNLOAD support |
|---|---|
| IBM® DB2® LUW | Yes, see details |
| IBM Informix | Yes, native SQL feature |
| IBM Netezza | Yes, see details |
| Microsoft™ SQL Server | Yes, with some limitations |
| Oracle® MySQL | Yes, see details |
| Oracle Database Server | Yes, with some limitations |
| PostgreSQL | Yes, see details |
| SAP HANA® | Yes, see details |
| SQLite | Yes, see details |