Get Example source ABAP code based on a different SAP table
Warning: Undefined variable $prev in /customers/b/9/9/trailsap.com/httpd.www/sap-help/index.php on line 54
ARTICLE
Relational Databases
The Relational Data Model Application software models a part of the real world. This type of modeling is based on the relational data model>. A data model describes reality using formal structures. In the relational data model, the only formal structure used is known as a relation or table. All the information about the modeled area of reality is represented as values in tables. A table is a two-dimensional matrix which consists of rows and columns (fields). The value range of a field (the set of permitted values for the field) is also known as the domain of the field. A field or combination of fields which uniquely identifies every row in a table is known as the key. This is a minimal attribute: if one of the fields is removed from the key, the remaining fields cannot uniquely identify the table rows. Each table must have at least one table key> (primary key integrity). However a table usually has multiple keys. During the modeling process, only one key is defined as the primary key>. In the relational model, the relationship between objects is expressed in terms of a foreign key>. A combination of fields in a table is known as a foreign key, if it is also the primary key in another table. In an AS ABAP>, the data model is managed in the ABAP Dictionary>, which results in a close compliance with the ABAP type concept >.
The Relational Database All the data relevant for all applications of an AS ABAP> is collected and managed centrally in a relational database>. All ABAP application programs work with this data by default. The largely standardized language SQL> can be used to access relational databases. Application Server ABAP supports database systems from different vendors. SQL is embedded in the ABAP language either with standardized Open SQL>> or vendor-specific Native SQL>>.
Note The primary table key (key fields for a database table of AS ABAP> that build the table key) can have a total size of 900 bytes. However if a key is larger than 120 bytes, the restrictions apply:
Table contents cannot be transported by specifying the complete key values. Instead you need to specify the generic key values with a maximum length of 120 bytes.
The table cannot be used as the base table of a lock object.