Data Dictionary SAP Data Dictionary and using Data Dictionary Objects, Tables, Views, Domains, Data elements and lock objects
Data Dictionary and What are main Functions of Data Dictionary in SAP ? SAP Data Dictionary is a central repository for the development of Objects, SAP Data Dictionary is used to create and maintain meta data ( data definitions ) . T-Code for Data Dictionary is SE11. SQL Can be divided into two parts
DML -- Data Manipulation Language
DDL -- Data Definition Language
Where DML consists of SELECT, INSERT, UPDATE, MODIFY, DELETE etc, this will be handled by ABAP Programs and DDL consists of commands like CREATE TABLE, DROP TABLE, ALTER TABLE, CREATE INDEX etc, this will be handled by Data Dictionary, hence Data Dictionary is the central repository for the development of objects . The Main Functions of Data Dictionary are :
Data Base Tables Views
Data Elements
Domains
Structures
Search Helps
Lock Objects
An ABAP Consultant may need to work on below areas of data dictionary :
Creating Tables Creating Data elements and Domains
Creating structures and Table types
Creating search helps
Creating Lock objects
Creating data base views
Navigation: T-code : SE11
Data Types-Domains-Data Elements ABAP uses different types of Data Types for Objects, basically there are three types of data types Elementary Data types, Complex Types, Reference Types . In Elementary types there are again two types of data types( Categories ) Fixed Length and Variable Length . Fixed Length:
C Text Field N Numeric
D Date
T Time
H Hexadecimal
P Parked Number
I Integer
F Float
Variable Length
STRING Character Sequence
XSTRING Byte Sequence
Complex Types includes Structure Types and Table Types. Reference Types includes Data References and Object References What is a Date Element in SAP ABAP ? Data element is an object which specified semantic information of a field, ex: field label , heading. ( We all know that table is a collection of fields, ex: STUDENT is a table with fields STUDENT_ID,
STUDENT_NAME ext, data element specifies the field labels and headings for these fields ) What is a Domain in SAP ABAP ? Domain is an object which specified technical information of a field in a table ex: Data type, length, value range etc Why we use Data elements and Domains in SAP ? When ever we are creating a new table or adding a field to existing table, we need to specify field labels and data types for the field, in SAP we maintain these values in the form of Data elements and Domains.
Creating Domain and Data Element Creating a Domain in SAP Go to SE11 T-code, select domain radio button, provide a name (ZSAPN_DOMAIN) and create.
Provide short description, no of characters and save (Ctrl S ).
Select local object ( non transportable object ).
Activate.
Domain is created.
Creating data element in SAP Go to SE11, select data type radio button, provide a name (ZSAPN_DATAELEMENT) and create.
A popup will open, select data element radio button
Enter short description and domain name (ZSAPN_DOMAIN) and select field label tab.
Select field label tab and maintain field labels.
Save and Activate, Data element is created.
Components of SAP Tables What are the components of database tables in SAP ? What is a key field, delivery class and size category in SAP ? Before creating a table we must know components of Table.
What is a key field ? A field which dosen`t accept duplicate data is called as key field.
What is a delivery class ? It specifies the type of data stored in a data base table ex: master data, Transaction data, system data etc Options available under delivery class : A- Application Table (Master and Transaction data ). C-Customizing table, maintenance only by customer not SAP. L-Table for storing temporary data. G, E, S, W - These are used to store system data (Basis data ).
Display and Maintenance It specifies whether the user can display the data and maintain the data , the following options are available under display and maintenance. 1. Display/Maintenance Allowed.- User can display and maintain data. 2. Display/Maintenance allowed with restrictions - Some users can display and maintain data. 3. Display/Maintenance not allowed - No user can display data.
What is data class ? It specifies the physical area of a table in the database, the following options are available under data class. APPL0 - Master data APPl1 - Transaction data APPL2 - Organization and Customizing DDIM, DFACT, DODS etc are used by BI and BW.
What is size category ? It specifies the number of records that can be stored in a database table, options available under size category are below. Size Category
No of expected records
0
0 - 7,100
1
7,100 - 28,000
2
28,000 - 1,10,000
The above numbers may vary from company to company . Size category will be incremented dynamically based on increase in records.
Buffer It is a temporary memory for storing the data . It is same as cache memory. The functionality of buffer is defined below.
Types of database tables in SAP What are the different types of database tables in SAP ? What are Transparent Tables, Pooled Tables and Cluster Tables in SAP ? There are three types of tables available in SAP, explained below
Transparent table There is a physical table on the database for each transparent table. The names of the physical tables and the logical table definition in the ABAP/4 Dictionary correspond. All business data and application data are stored in transparent tables.
Pooled table Pooled tables can be used to store control data (e.g. screen sequences, program parameters or temporary data). Several pooled tables can be combined to form a table pool. The table pool corresponds to a physical table on the database in which all the records of the allocated pooled tables are stored.
Cluster table Cluster tables contain continuous text, for example, documentation. Several cluster tables can be combined to form a table cluster. Several logical lines of different tables are combined to form a physical record in this table type. This permits object-by-object storage or object-by-object access. In order to combine tables in clusters, at least parts of the keys must agree. Several cluster tables are stored in one corresponding table on the database.
Creating Table in SAP How to create a Transparent Table in SAP data dictionary ? What in Top to Bottom and Bottom to top approach to create database tables in SAP ? A table can be created in two ways one is top to bottom approach and another one is bottom to top approach. 1.Top to Bottom : In this approach, first table fields are defined and later domain and data element are defined. 2.Bottom to Top : In this approach, first domain and data element are defined and later table will be created . In this example we are going to learn creating a SAP transparent table using top to bottom approach ( I suggest simplest way ). Go to SE11 T-code, provide table name to be created ZSTUDENT_TABLE and create.
Provide short description, delivery class (A), Display Maintenance Allowed and select fields tab.
Select Fields tab, add a field STUDENT_NO, data element as ZSTUDENT_NO and check Key and Initial Value check boxes. A table must contain at least one key field, without a key field we can not create a table.
Double click on data element ZSTUDENT_NO (Not yet created), a pop up will open click yes and one more information message will come press enter. Now a pop up will come asking to create date element, click yes.
Provide short description, domain and label
Save, double click on domain name ZSTUDENT_NO, click on yes. Provide short description, data type, no. characters, save and activate.
Similarly create remaining fields with data elements and domains as below
Once all fields are created click on technical settings button.
Provide data class and size category, save and activate.
You will get a warning message just click on No, table is created. Now add entries to table.
Creating Structure in SAP What is a structure in SAP Data Dictionary ? How to create a Structure in SAP data dictionary ?
Structure Structure is list of fields defined under a name, which is used to process data at run-time in SAP ABAP applications. Structures are two types one is global structure and another one is local structure. Local structure can be created in ABAP programs and global structure can be created in data dictionary and can be reusable in different objects. In this lesson we will be learning creating a structure in data dictionary. Go to SE11, select Data Type radio button and click on create.
A pop up will open, select structure radio button and continue.
Provide short description, add some fields, save and activate.
The structure is created, now we can use this structure in our ABAP programs.
Difference between structure and table in SAP data dictionary Table and structure have lot of differences in the sense of behaviour and properties, the below are the main differences between table and structure in data dictionary.
Table and Structure Difference Table
Structure
Table can store data physically and permanently.
Structure can not store data physically, it can hold data at run time only.
Table have primary key.
Structure dosent have any primary key.
Table have technical settings (data class, size category
Structure dosen`t have any technical
etc), maintanance attributes ( Display maintanance
attributes and maintatance attributes.
restrictions ). Table have primary and secondary indexes.
Structures dosen`t have primary and secondary indexes.
Difference between Transparent, pooled and cluster tables in SAP The below are the major differences between transparent, pooled and cluster tables in SAP data dictionary . Transaparent Tables
Pool Tables
Cluster Tables
Contain a single table. Used to store master data
They are used to hold a large number of very small tables(stores system data).
They are used to hold data from a few number of large tables. (stores system data).
It has a one-to-one relationship It has a many-to-one with a table in the database. relationship with a table in the database.
It has a many-to-one relationship with table in the database.
For each transparent table It is stored with other pooled there is one associated table in tables in a single table called the database. table pool in the database.
Many cluster tables are stored in a single table in the database called a table cluster .
The database table has the same name, same number of fields and the fields have the same names .
The database table has The database table has different different name, different name, different number of fields number of fields and fields have and fields have different names. different names.
There is only a single table .
Table pools contain more tables Contains less tables than table than table clusters . pools .
Secondary indexes can be created .
Secondary indexes cannot be created .
Secondary indexes cannot be created .
Table Validations using check table What is a check table in SAP ? Data validations on SAP tables using check table, creating check table in SAP
What are table validations ? Table validation is a concept through which we can restrict invalid entries in a table.
Possible methods/concepts for table validation 1. Field Level validations: We can validate entries at field level with the help of check table concept. 2. Domain level validations: We can restrict entries at domain level with the help of fixed values of domain and value table of domain.
What is check table ? It is a table which contains all valid entries of a field.
What is value table ? It is a table which contains all valid entries of a domain, this domain can be reused in multiple tables.
What are fixed values for domain ? These are allowed values for a domain ex: GENDER (domain).
Creating check table for table validations. Step1: Go to SE11, create a table ZSTUDENT_CHECK as below Go to SE11, provide name as ZSTUDENT_CHECK and click on create.
Provide delivery class and display maintenance allowed.
Go to fields tab and add field as below
Click on technical settings button and provide data class and size category.
Go to utilities- table contents - create entries add some entries to the table.
Similarly add some more entries.
Step2: Add ZSTUDENT_CHECK as check table for ZSTUDENT_TABLE Go to SE11, provide table name as ZSTUDENT_TABLE( which we have created already in our previous lessons, if not create a table )
Go to tab Entry help/check, select city fields and click on foreign key icon.
Provide short text, check table name ZSTUDENT_CHECK and click on generate proposal and click on copy.
A check table will be added for CITY field
Save and activate the table(If you get a warning popup when activating just press no). Now go to utilities - table entries -> create entries Provide a city name which is not in ZSTUDENT_CHECK table and try to save, it will trough an error.
Fixed Values for domain in SAP SAP Table screen entries can be restricted using domain fixed values, we can maintain domain fixed values at domain level when creating a domain.
Create domain with fixed values Go to SE11, select domain, provide name as ZGENDER, click on create.
Provide short description, data type and length as below and click on value range tab.
Provide fixed values.
Save and activate.
Create data element with domain Go to SE11, select data type, provide name as ZGENDER, click on create .
A popup will come, select data element and press enter.
Provide short description, domain and click on field label.
Provide field labels
Save and activate
Add a field in table Go to SE11, provide a table name ZSTUDENT_TABLE(we have already created, if not create table ) and click on change
Go to fields tab and add a field as below.
Save and activate Go to table utilities- table entries - create entries
Provide values other than M, F and N, it will through an error .
