SQLer for Open Systems
SQLer is a module to develop portable applications,
independent from the relational database used. SQLer implements the
XPG3 specifications to build a database, to modify its structure and to
access the data. SQLer translates these specifications towards the
target database management systems.
Using SQLer in open mode, the developers can also use the target
dynamic SQL dialect directly.
SQLer supports the host-based and the client/server architectures.
Data Definition Language
Starting from a conceptual model and an internal schema,
SQLer produces a command file for the SQL interpreter of the target
database.
The internal schema maps the conceptual domain definitions of SQLer
upon the data types supported by the target database. The index
management is included in the internal schema. SQLer always enforces
entity integrity and provides referential integrity on request.
You can change an existing database with the SQLer DDL. You don't need
to unload and reload your data when changing the database schema. New
columns are created with their default value. When a column data type
is modified, the data are converted from the old data type to the new
one.
Data Manipulation Language
The SQLer DML takes care of the data type conversion
between the databases and the host language. SQLer provides standard
error messages but still allows to read and test the database specific
(native) error messages. Of course, SQLer DML allows to access any
stored procedures.
Host-based SQLer (4 modes)