Developer's Journal: ABAP/HANA Connectivity via Secondary Database Connection

Introduction

In this first edition of this HANA Developer's Journey I barely scratched the surface on some of the ways which a developer might begin their transition into the HANA world. Today I want to describe a scenario I've been studying quite a lot in the past few days: accessing HANA from ABAP in the current state.  By this, I mean what can be built today.  We all know that SAP has some exciting plans for ABAP specific functionality on top of HANA, but what everyone might not know is how much can be done today when HANA runs as a secondary database for your current ABAP based systems.  This is exactly how SAP is building the current HANA Accelerators, so it’s worth taking a little time to study how these are built and what development options within the ABAP environment support this scenario.

Developer’s Journal: HANA Catalog Access from ABAP

Introduction

I introduced the topic of ABAP Secondary Database Connection and the various options for using this technology to access information in a HANA database from ABAP. Remember there are two scenarios where ABAP Secondary Database Connection might be used.  One is when you have data being replicated from an ABAP based application to HANA. In this case the ABAP Data Dictionary already contains the definitions of the tables which you access with SQL statements.

The other option involves using HANA to store data gathered via other means.  Maybe the HANA database is used as the primary persistence for completely new data models.  Or it could be that you just want to leverage HANA specific views or other modeled artifacts upon ABAP replicated data.  In either of these scenarios, the ABAP Data Dictionary won’t have a copy of the objects which you are accessing via the Secondary Database Connection. Without the support of the Data Dictionary, how can we define ABAP internal tables which are ready to receive the result sets from queries against such objects?

In this blog, I want to discuss the HANA specific techniques for reading the Catalog and also how the ABDC classes could be used to build a dynamic internal table which matches a HANA table or view. The complete source code discussed in this blog can be downloaded from the SCN Code Exchange.