SAP DATABASE ACCESS GUIDL documentation, setup help and example usage

GUIDELINE 5.23

Database Accesses

ABAP_BACKGROUND
In ABAP, data in database tables can be accessed in the following ways:

Open SQL

Implemented by ABAP statements, this is a subset of the Structured Query Language ( SQL ) comprising the DML (Data Manipulation Language) part. The statements of Open SQL use the Open SQL
interface to access, independently of the platform, the database tables of the database of an AS ABAP that are defined in the ABAP Dictionary.

Native SQL

Database-specific SQL statements that include both DML and
DDL (Data Definition Language) statements and which can be passed to the Native SQL interface of the database as follows:

The methods of ADBC make it possible to execute dynamic SQL statements on a database system and process the results. ADBC ( ABAP Database Connectivity ), a class-based API that enables object-oriented access to the Native SQL interface.

Native SQL statements can be specified in ABAP programs between the statements EXEC SQL and

ENDEXEC . Static Native SQL statements of this kind are not checked completely by the syntax check and are forwarded almost unchanged from the Native SQL interface to the database of an AS ABAP .
All access types enable access, not only to the central database of an AS ABAP (standard connection), but also to other databases, using additional connections.

ABAP_RULE
Using Open SQL
Use Open SQL for general persistence services where possible. Only use Native SQL for tasks where Open SQL is not suitable.

ABAP_DETAILS
Only Open SQL is guaranteed to be independent of the database platform used. For this reason, Open SQL does not contain the set of all possible SQL statements in a specific database, but only a subset of the DML scope of all database systems supported by
AS ABAP . The database tables that can be processed using Open SQL
can be used in ABAP directly as structured types for the declaration of suitable work areas. Only Open SQL supports SAP buffering of table content in the shared memory .
Native SQL should only be used if the task really cannot be solved using Open SQL . Services that work with Native SQL are generally dependent on the database system used, so that they cannot be executed in all AS ABAP systems. For platform-independent services, implementations should be provided for all supported databases.
If the database is to be accessed using the Native SQL interface instead if the Open SQL interface, ADBC
should be used. ADBC is a modern object-oriented API
that is better suited to modern ABAP programming than
EXEC SQL . Enhancements to the Native SQL interface, such as bulk access using internal tables, are now only provided using ADBC . ADBC also enables dynamic access ; Native SQL
on the other hand is just static.