8. ABAP Dictionary views Flashcards
View
A view is an object, like the telescope, that provides a picture of something. In its most basic form, a view simply mirrors an entire database table. It looks just like the table and it acts just like the table – but it isn’t actually the table.
We can use views to
Join several tables
Project (or choose) certain fields from one or more tables
Select (or choose) certain records from one or more tables
Relational Operations
Join, projection, and selection
Projection operation
is used to narrow a view’s focus to certain fields in a table.
Selection operation
is used to narrow a view’s focus to certain records in a table.
Join Operation
is used to combine information from multiple tables into a single view.
Types of views
- Database view
- Projection view
- Help view
- Maintenance view
Database view
The database view is the only type of view in SAP that is physically created at the database level. In other words, the underlying database system also directly recognises the view, apart from SAP. Therefore, database views must be created over transparent tables.
Projection view
The projection view is a logical view. In this context, the word “logical” means that the view exists within the ABAP Dictionary but is not recognised by the underlying database system.
The only relational operation that is valid for a projection view is projection.
Help views
Help views can be used as selection methods for Search Helps. It might be necessary to create a Help View if you are trying to accomplish an outer join, since database views only create inner joins.
Maintenance views
These views permit maintenance of base table data. Transactions SM30 and SE54 are provided for working with maintenance views.
