Basics of ABAP : Data Dictionary Objects

¨ Table: is a 2D data matrix containing rows and columns. Rows contain data while column indicates fields. Table can contain 0 or multiple rows.

¨ Structure: is a skeletal view of a table. It contains the definition of columns and don’t have any contents. Structure is generally a template based on which a table is created. The basic difference between structure

and table is that the structure does not exist at the underlying database system level. Structure exists as definition in the dictionary.

¨ Views: A view is an imaginary table. It contains data, which is really stored in other tables. The contents for the view are dynamically generated when called from program. 

¨ Dataelement: is definition of the properties and type for a table field. It is an intermediate object between the object type domain and the table field. A field in R/3 system is always associated with a data element,

which at the same time is related to domain.

¨ Domain: is formal definition of the data type from a technical point of view. It sets the attributes such as data type, length, possible value range and so on.

¨ Lock objects: These types of objects are used for locking the access to database records in table. This mechanism is used to enforce data integrity that is two users cannot update the same data at the same time.

With lock objects you can lock table-field or whole table.

¨ Search Help Objects: , which gives list of possible values for either primary keys or non-primary keys.