abap - data dictionary

Data Dictionary

Day 2

We will learn about…

• What is Data Dictionary• Data Dictionary Objects• System Fields• Creating custom table• Internal Tables• Foreign Keys & Cardinality• Structures• Views

What is Data Dictionary

• is a system independent

interface to the database

• is a virtual database ( data

about data)

• provides data for data

manipulation and data

processing

• Also called as DDIC and ABAP

Dictionary

Data Dictionary Objects

• Data Element

• Domain

• Tables

• Structures

• Views

SE16

Elementary Data Types

Type Explanation

C Text (Character)

N Numeric text

D Date (DDMMYYYY)

T Time (HHMMSS)

X Hexadecimal

I Integer

P Packed Number

F Floating point number

Domain• A Domain describes the technical structure of a field that is its size and

its data types.

• Domains are attached to Data Elements

• Fields which refer to the same domain (with the assigned data elements), are also changed when the domain is changed. This ensures that the fields are consistent

• Defines a value range which describes the valid data values for all the fields which refer to this domain

Domain

MATNR

CLNT

Table MARA

Data Element

Creating a Domain

Enter a description (short text)

Enter data type and length

Creating a domain (contd.)

Enter fixed value and description.

Value table may be entered

Data Element

• A data element gives the description of the field of the Table

• Examples of predefined data elements in SAP– LIFNR– KUNNR– MATNR– CLNT

Creating a Data Element


Enter domain name

Creating a Data Element

Maintain field labels and column headers.

Difference between Domain & Data Element

Domain Data Element

Defines Technical Attributes such as data type, length, allowed values, etc.

Defines semantic attributes such as display length, short text, long text, etc

A domain can be part of several data elements

A Data Element can point to only one domain

Used to define data elements, restrict values (using value range, value table, etc)

Used to define fields of tables and screens

A Holistic view

Data element Data element

Domain

Table A Table B Table C

Tables

• Tables are containers which stores data in the form of record

• They are a central component of the SAP R/3 Application• One or more fields form a data record (also known as tupel)

• A number of data records of the same type form a table• Examples of few SAP defined tables

– MARA : Material Master

Tables Contd…

The table definition contains the following components

Table fields: defines the field names and data types of

the fields contained in the table.

Foreign Keys: defines the relationships between the

table and other tables.

Technical Settings: control how the table should be

created on the database.

Indexes: speed up the selection of data from the table.

Tables Contd…

• Types of Tables

ABAPDictionary

ABAPProgram

Transparent

Cluster

Pool

Internal

Tables Contd…

Creating a Transparent Table – Step 1 of 6

Enter the Name of the table (should begin with “Z” or “Y”)

Enter the Name of the table (should begin with “Z” or “Y”)

Press the Create ButtonPress the Create Button



Maintain delivery class

Table maintenance attribute

After making all entries, Press the “Fields” Tab

After making all entries, Press the “Fields” Tab


Maintain field attributes

Maintain data elements

After making all entries, Press the “Technical Settings” Button

After making all entries, Press the “Technical Settings” Button


After making all entries, Press the Save Button. Once Technical Settings are save, Press the “Back” Button (F3)

After making all entries, Press the Save Button. Once Technical Settings are save, Press the “Back” Button (F3)


Save, Check and Activate the Table. After that Press the “Indexes” Button on the Application Toolbar

Save, Check and Activate the Table. After that Press the “Indexes” Button on the Application Toolbar

Creating a Transparent Table – Step 6 of 6Steps to create an index

After entering the Index Fields and other parameters, save and activate the index, Z01

After entering the Index Fields and other parameters, save and activate the index, Z01

SAP Transparent Tables

• Example of few SAP Transparent Tables– MARA : General Material Data– VBAK : Sales Document: Header Data– KNA1 : General Data in Customer Master

• Example of SAP Cluster Table– BSEG : Accounting Document Segment

Tables Contd…

• Foreign Keys– Uses

• Maintain data integrity

• Provide help texts

• Create aggregate dictionary objects

– Prerequisites• The foreign key text field and primary key of the check table must

share the same domain

• A value table must exist for that domain

Tables Contd…

• Cardinality

– Cardinality defines the type of

relationship between two tables

– The cardinality of a foreign key

indicates how many dependent

records a record in a check

table may have

1 : 1

1 : C

1 : N

1 : CN

Cardinality Types

System fields

• SAP has a system table named syst. It stores all the system related data

• Examples of few fields in this table are– Sy-datum : System Date– Sy-langu : System Language– Sy-subrc : System check– Sy-uzeit : System time

SAP Data

ConfigurationData

MasterData

TransactionData

SystemData

• Sales Orders• Purchase Orders• Journal Entries• Goods Receipts

• G/L Accounts• Vendors• Materials• Stock Locations

• Metadata• Programs• Documentation• System Settings

• Currency Codes• Order Types• Payment Terms• Field Status Codes

Structures

• A structure is defined like a table in the ABAP Dictionary and can then be accessed from within ABAP programs

• Contain data temporarily during program runtime

• The same data elements and domains can be used in structures as in tables

Views

• A view combines the data distributed in several tables

• Views allow to gather information from fields of different tables and present it to the users in form they require when working in the R/3 system

abap - data dictionary

Documents