DATA DICTIONARY

Data Dictionary

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 • The T-Code for DDIC is SE-11.

Data Dictionary (SE11)

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

Table Components • A table contains Fields that are composed of a Data element that uses a Domain. – The domain contains the technical characteristics of a field, such as the field length and data type. – The data element contains the field labels and online documentation .

Components of table

Domain •

A Domain describes the Technical structure of a field that is its size and its data types.

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Domains are attached to Data Elements

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

Creating a Domain

Enter a description (short text) Enter data type and length

Creating a domain (contd.)

Enter fixed value and description.

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 a description (short text)

Enter domain name

Creating a Data Element

Maintain field labels and column headers.

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.

Types of Tables

Transparent ABAP Dictionary

Cluster Pool

ABAP Program

Internal

Transparent Table. • A transparent table in the dictionary has a one-toone relationship with a table in the database. • Its structure in R/3 Data Dictionary corresponds to a single database table. Has one to one relationship with a Db table. – Used to hold application data or master data used by application. – Has the same name and fields as the Db table.

POOLED TABLES • Holds customizing data from many database tables and they have many-to-one relationship with a database table . • For one database table, there are many tables in the dictionary ( with different table name; different field names and different number of fields). Each pooled table contains table description.

Cluster Table – Holds data from a few very large tables (like joining tables on common part of primary key). It has many-to-one relationship with a database table. Many clustered tables are stored in a single database table called a table cluster. – (Pooled tables and clustered tables are usually used only by SAP)

Creating a Transparent Table – Step 1

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

Press the Create Button

Creating a Transparent Table – Step 2

Enter a description (short text) After making all entries, Press the “Fields” Tab

Maintain delivery class

Table maintenance attribute

Creating a Transparent Table – Step 3 After making all entries, Press the “Technical Settings” Button

Maintain field attributes

Maintain data elements

Creating a Transparent Table – Step 4 After making all entries, Press the Save Button. Once Technical Settings are save, Press the “Back” Button (F3)

Creating a Transparent Table – Step 5 Save, Check and Activate the Table. After that Press the “Indexes” Button on the Application Toolbar

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

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 Master Data

• • • •

G/L Accounts Vendors Materials Stock Locations

System Data Transaction Data

• • • •

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Metadata Programs Documentation System Settings

Sales Orders Purchase Orders Journal Entries Goods Receipts

Configuration Data

• • • •

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 • The data of a view is derived from one or more tables, but not stored physically. • Data that can be selected with a view depends primarily on whether the view implements inner join or outer join.

Types of Views • SAP R/3 supports four types of Views • • • •

1) Database View 2) Projection View 3) Help View 4) Maintenance View

Database View • A database view provides an application-specific view . If the database view only contains a single table, the maintenance status can be used to determine if data records can also be inserted with the view. If the database view contains more than one table, you can only read the data.

Projection View • A project view contains exactly one table. • You cannot define selection conditions for selection views. • Project views are used when you required to use only few selected fields in your view.

Help view • You have to create a help view if a view with outer join is needed as selection of a search help. • Only foreign keys that have certain attributes can be used here.

Maintenance View • A maintenance view permits you to maintain the data of an application object together. • Only those tables that are linked with the primary table (indirectly with a foreign key can be included in the maintenance view).

How Search Help works?

1. The user starts the input help to display the possible input values for a field. 2. The system offers the user a number of possible search paths 3. The user enters restrictions if required and then starts the search. 4. The system determines the values that satisfy the entered restrictions (hits) and displays them. 5. The user selects the most suitable line from the hit list by double-clicking

Search Helps • Selection method to limit data records used in table selection. • Allows you to include to field input help. • In R/3 you can create two types of search helps. • 1) Elementary Search help • 2) Collective search help

Elementary Search Help • Where does the data displayed in the hit list come from (selection method) • What information should be displayed in the dialog box for value selection and in the hit list (search help parameters)

Collective Search Help • A collective search help combines several elementary search helps. The user can thus choose one of several alternative search paths with a collective search help.

Lock Objects • The R/3 System synchronizes simultaneous access of several users to the same data records with a lock mechanism. When interactive transactions are programmed, locks are set and released by calling function modules. These function modules are automatically generated from the definition of lock objects in the ABAP Dictionary.

Lock Objects • Activating a lock object in the ABAP Dictionary automatically creates function modules for setting (ENQUEUE_) and releasing (DEQUEUE_) locks.

• The generated function modules are automatically assigned to function groups. You should not change these function modules and their assignment to function groups since the function modules are generated again each time the lock object is activated.

Thanks