Preface – This post is part of the ABAP Beginner series.

Projection View in SAP ABAP

As the name suggests, Projection View in SAP ABAP Projects few fields of a table. Let us understand it with an example, suppose you have an Employee Details table that contains data regarding employee basic details, Employee Address details and Employee Salary Details. You want Address Verification team to just see the Employee Address details. In this case you will create a Projection View of that table.

 

Definition

A Projection View in SAP ABAP is a view that contains exactly one table. It projects only those fields that are assigned to the view.

*NOTE: The tables can be any transparent, cluster or pool. We don’t define any selection/Join condition for Projection Views.

For basics of Views Click Here.

Creation of Projection Views:

Step 01: Open SE11, select Views radio button, and enter a name for your view e.g. ZBARRY_VIEWS and click CREATE. Choose Projection Views from radio buttons.

Step 02: Write an explanatory short text e.g. Views for Employee Details.

Step 03: Enter your Table name in Basis Table Field.

Step 04: Select View Fields tab, click Choose Table Fields, select the required fields from Dialog Box and click COPY.

Step 05: Save it, check for Errors and click Activate.

*NOTE: You can further specify Maintenance Status. There are more functions and additional optional of Projection View, we will update it soon.

Advantages of Projection View in SAP ABAP

• Selection of Data from View is faster.
• It helps to display only required & relevant data.
• It limits full data access to unauthorized users.

[embedyt] https://www.youtube.com/watch?v=4VH6Fn6jqbk[/embedyt]

Preface – This post is part of the ABAP Beginner series.

Database View in SAP ABAP

As the name suggests Database View in SAP ABAP is a view that integrates several distributed database and helps us to view all data at one place. We can access data of Database View using SQL commands (SELECT Statements). It implements inner join for integration. It can even contain a single table without any Join statement. And if there is only table then we can maintain data also otherwise we can just read only.

Definition

A Database View in SAP ABAP is a view which combines multiple tables in to a single View and is used only to read the records.

*NOTE: If only one table is there then it can be maintained too.

For basics of Views Click Here.

Creation of Database View in SAP ABAP:

Step 01: Open SE11, select Views radio button, and enter a name for your view e.g. ZBARRY_VIEWS and click CREATE. Choose Database Views from radio buttons.

Step 02: Write an explanatory short text e.g. Views for Admin Dashboard.

Step 03: Write all your table names you want in your view in column Tables.

Step 04: Now you need to write Join Conditions or just click  if you have earlier specified the foreign keys in tables; it will automatically write the Join conditions for you based on your foreign key relationship. [To know more about Foreign Keys CLICK HERE]. 

Example of a JOIN CONDITION.

Step 05: Click View Fields and then click Table fields, Select the fields from each table that you want to be visible in your View.To know more about Joins CLICK HERE.

Step 06: Save it, check for Errors and click Activate.

*NOTE: You can further go in technical settings of View and specify Buffer. There are more functions and additional optional of Database View, we will update it soon.

Advantages of Database Views

• Selection of Data from Views is faster than Selection of Data from individual tables.
• It helps to select data from logically connected tables.

[embedyt] https://www.youtube.com/watch?v=IIXCz86eyL0[/embedyt]

Preface – This post is part of the ABAP Beginner series.

Inner Join and Outer Join

Inner Join and Outer Join are the two different ways to join two tables. Both of them produce different result. In this article we will learn both of them.

Suppose you have two tables with two fields and following data as shown below:

Table 1

Table 2

Now if you want data that is common in both the table then you will apply Inner Join and get following results:

And if you want all data irrespective of its presence in any table, you will apply outer join and get results as shown below:

Now let see definition of both of the Joins.

Definition

Inner Join

A join that is utilized by Database views which gives the cross-product of the records present in both table.

[For basics of Joins click here]

Outer Join

A join that shows the cross-product of all the records present in different tables. It is utilized by Help Views, Projection Views and Maintenance Views. [For basics of Views click here]

It is of two types:

1. Left Outer Join: It is just like outer join, it includes all the results of Outer Join with all data from the left table.
2. Right Outer Join: It is also just like outer join, it includes all the results of Outer Join with all data from the right table.

 

Preface – This post is part of the ABAP Beginner series.

Joins in SAP ABAP

In View, we need to join two tables; these two tables can have or cannot have Keys in common. In case of View we give Join Condition (e.g. table1-field1 = table2-field1) on basis of which records are merged. Joins in SAP ABAP can also be applied on two tables without a Join condition and in that case it will just give cross product of the two tables.

Definition

Joins in SAP ABAP are cross product of two tables which further uses Join Condition to produce desired output.

Join Condition: When the cross product of two tables doesn’t give desired result, then a condition is written which tells us how the tables are connected. A statement is written where fields of each table are written with table name and equality operator.

e.g. table1-field1 = table2-field1

 

Example:

If we have two table as shown below and we apply

1. Join without any Join Condition

2. Join with Condition

Here the rows who don’t meet the condition are deleted.

 

 

Here the column which comes in right hand side of the Join Condition is also deleted.

 

 

This is the actual View as output.

*NOTE:  It is not necessary to compare two fields of different table to form a condition. A condition can also be like Table-Field1 = 1.

Types of Join

1. Inner Join
2. Outer Join

*Note:

1. Pooled & Cluster tables cannot be joined via Join statement.
2. In a single SELECT statement we must define at max 49 JOINS and specifying each table a namespace using AS.
3. A WHERE condition applied with JOIN statements are actually applied on the results of the JOIN statements.
4. If same column name appears in multiple tables, then its source is specified using column selector i.e. (~).
5. JOIN expressions bypass BUFFERING. We can access table buffer by using FOR ALL ENTRIES.

Preface – This post is part of the ABAP Beginner series.

Views in ABAP

Have you ever seen the views outside your window? Let’s suppose that a beautiful girl leaves just in front of your house with her parents. Now suppose you have a big window in your room from where you can see windows of both the girl and her parents. If you just want to see the girl, then you can use curtains to hide one part of the window, if you want to check her parents’ activity you can move the curtains again. That is Views in ABAP.

Views in ABAP helps us to see what we want to see from one table or many.

 

Definition

A View is a reusable object which doesn’t stores any data physically but is derived from one or more tables.

Mandatory steps to make Views in ABAP

 

Step 01: Open SE11 and choose Views Radio Button. Enter the name and Type of the View

Step 02: Select the tables for view.

Step 03: Link tables using Join Conditions.

Step 04: Select the fields from tables; these will be only visible in the views.

Step 05: Define the selection conditions which will restrict the records in the view.

 

Types of Views

 

VIEWS TYPE	JOIN USED	Description
Database Views	Inner Join	A View that integrate multiple Table into a single View.
Projection Views	N.A	A View that shows only few fields of single Table.
Help Views	Outer Join	A Search Help can show data from Table or Structure. But if you need data from multiple tables then we create a Help View for Search Help.
Maintenance Views	Outer Join	Unlike Database View where you can only View Data, if you want to maintain multiple Table @ a single place using View then we create Maintenance Views.

 

*NOTE: To know more about Joins click here.

 

Example

Requirement: You have three tables of Employee:

1. ZEMP_DETAILS that have Employee Details like Employee ID, USERNAME, PASSWORD, NAME, and Date of Birth.
2. ZEMP_ADDRESS that have Employee Details like Employee ID, Employee Address, Town, State, and Country.
3. ZEMP_SALARY that have Employee Details like Employee ID, Employee Basic Salary, Allowance and Tax.

Now you want to view all the details of an employee altogether. What will you do?

 

Proposed Solution:  We will create a view which will be based on Employee ID.

From above View we can see how we can project multiple tables altogether.

Preface – This post is part of the ABAP Beginner series.

ABAP Table Index

Suppose you have a million unsorted records and you want to perform search on the basis of non primary key. Then it will take a lot of time to process all the records. In this case you will make something called Secondary Indexes or ABAP Table Index.

Definition

An Index is a sorted copy of Database which contains pointer pointing to non-key fields which is used to increase the search speed of a table.

Types of Indexes

Primary Index:

The Primary Index is an Index created by system itself just after the creation of table. It contains only key fields. It has ID 0.

Secondary Index:

When your search criteria are not fulfilled by Primary Index, then in this case we can create our own Indexes called Secondary Indexes. Its ID can be of max 3 digit alphanumeric value. The total length of Index Name can be of 13 digit which includes table name and Index ID.

The naming convention of Secondary Indexes:

<TABLE_NAME> ~ <INDEX_ID>

e.g.  ZBARRY_ALLEN ~ A.

 

Unique Index:

If we define an Index as Unique Index if we want only unique records or unique combination of field in the table.

e.g. If you have defined two field combination as Unique. Then only unique values will be inserted. For more visit ABAP Documentation.

Extension Index:

A secondary Index is temporary index and needs recreation after every upgrade. If we create Extension Index it is upgrade protected. We don’t have to do anything new, just choose Extension Index in step 02 below.

How to Create a Secondary ABAP Table Index:

Step 01: Create a table and in the maintenance screen click on Indexes. [How to Create a table: Click here]

Step 02: Choose New Icon  and click Create.

Step 03: Choose Index from Drop Down box. Enter Index ID and click CONTINUE.

Step 04: Enter an explanatory Short Description.

Step 05: Choose Table Fields, choose desired fields and choose COPY.

*NOTE: The order of the field is important.

Step 06: If the values in the index are always unique then choose Unique radio button else leave it.

Step 07: According to the use of Index choose one of the radio button:

Radio Button	Description
For all database systems	If it will be used across all database systems
For selected database systems	If only for selected database systems. You can select at max 4.
Not at all in the database	If it is an exclusive Index

 

Step 08: Save it, Check for Errors and Activate it.

Disadvantages of Index

More the number of ABAP Table Index, the more load on the system, as it needs to adjust Indexes every time you Insert, Update or Delete a record. Due to which Table which is written frequently must have less indexes.

Preface – This post is part of the ABAP Beginner series.

Table Buffering in SAP ABAP

Before we start with “Table Buffering in SAP ABAP”. Let us take a general example. Have you ever used YouTube? And, have you ever buffered video before watching it?

If YES, then you already have the idea of Buffering.

And If not, go to YouTube and pause your video, it will load it (Buffer it). So in this scenario, the YouTube video is loaded in your Browser/Application and when you play it, it doesn’t load it anymore from YouTube Server but directly plays it from the Buffer of your Application Server.

In this way you save your time and have a better experience. This concept of Buffering is also utilized by ABAP Tables and termed as Table Buffering in SAP ABAP.

Definition

Table Buffering in SAP ABAP is a concept in ABAP Tables to enhance performance (10 to 100 times) and reduce time of processing (accessing) the table.

A Buffer is an interface between Database layer and Application layer. Application Layer communicates with Buffer and the Buffer communicates with Database layer and vice-versa.

*NOTE: Database Interface determines whether the Data is in buffer or not. If not, it takes data from database and also syncs the Buffer.

Using Buffers in Table

Step 01: Choose one radio button from Buffering Permissions.

Permission	Description
Buffering not allowed	This is default value. It is for Transaction table where data changes frequently
Buffering allowed but switched off	Buffer is allowed but it is switched OFF and can be switched ON anytime according to the requirement of customer
Buffering switched on	Buffering is allowed. In this case we need to provide the Buffering type.

 

Step 02: Choose the buffering type: It defines which data will be loaded and when.

Buffering Type	Description
Full Buffering	System loads all the data into Buffer whenever single record of the table is accessed.
Generic Buffering	When a record with a specific Generic key is accessed, all other records of that Generic key are also buffered.
Single-record Buffering	Only the record that was really accessed is buffered.

 

Full Buffering

When Full Buffering is used then either entire table is buffered or none of the records will be buffered. When a single record is accessed, the entire data/record of that table is buffered. By Buffering we mean that all the record is in the buffer table.

When To Use Full Buffering

• Larger table is rarely written and frequently read like Master Table, and then we need to use Full Buffering.
• For small tables like customizing tables that are mainly read.

Generic Buffering

When Generic Buffering is used, all the records with Generic keys are buffered all at once.

*NOTE:

• Generic Keys: The key combination of only certain keys that is used to filter data from table.
• Generic key is a part of Primary key.
• All the Generic keys should be mentioned in WHERE condition of SELECT statement otherwise Buffer is bypassed and data is read from Database.

When To Use Generic Buffering

• When only certain Generic Areas are needed.
• For Client Specific Tables, the Client field is the Generic key.
• For Language Specific Tables, The Generic key includes Language key.

Single-Record Buffering

All the Data that you have accessed will be buffered and nothing apart from them.

When To Use Single-Record Buffering

• Table where only few records are accessed

How to Bypass a Buffer

By using BYPASSING BUFFER we can bypass the buffer and read directly from database.

SELECT * FROM <TABLE_NAME> INTO TABLE <ITAB> BYPASSING BUFFER.

 

 

Preface – This post is part of the ABAP Beginner series.

Delivery Class in ABAP Tables

In Data Class we have specified the Type of Data we will be using for our table, in Size Category we have declared the expected Volume of Data we will be saving. Now, we need to define the way the Data in the table behaves. It means whether data can be moved from one Landscape/system to other or not. It is achieved using Delivery Class in ABAP Tables.

*NOTE: Although the Delivery Class is declared before Data Class and Size Category, still it is advisable to read about it after them.

Definition

A delivery class defines:

• Transport control of Data within Landscapes and customer systems
• Transport control of Data for an installation or upgrade
• Transport control of Data of client copy
• Data can be maintained in Extended Table Maintenance [SM30] or not.

In short we can say a delivery class determines whether data of the table can be maintained & transported or not.

Types of Delivery Class

TYPE	TABLE TYPE	DESCRIPTION	TABLE BEHAVIOUR DURING CLIENT COPY	TABLE BEHAVIOUR During Installation, Upgrade and Language Import
A	Application table (Master and Transaction data)	Master and Transaction data is maintained by SAP	Data is copied only if requested	·         Cross-Client Tables : No Data Imported ·         Client-Dependent Tables: Data Imported into Client 000.
C	Customer table	Data is only maintained only  by Customer	Data is copied to the target client	·         Cross-Client Tables : No Data Imported ·         Client-Dependent Tables: Data Imported into Client 000.
G	Customer table	SAP can only Insert data & cannot modify/Delete	Data is copied to the target client	·         Cross-Client Tables : Imported and cannot be overwritten ·         Client-Dependent Tables: Imported and can be overwritten only for CLIENT 000.
L	Temporary table	Table to story only temporary data	Data are not copied to the target client	·         Cross-Client Tables : No Data Imported ·         Client-Dependent Tables: No Data Imported.
E	System table	Table with own namespace(in table TRESC) for customer entries	Data is copied to the target client	·         Cross-Client Tables: Imported and can be overwritten with same key. ·         Client-Dependent Tables: Imported and can be overwritten.
S	System table	Table with status of Data changes	Data is copied to the target client	·         Cross-Client Tables: Imported and can be overwritten with same key. ·         Client-Dependent Tables: Imported and can be overwritten.
W	System table	Table whose Data is Transported via its own Transport Objects	Data are not copied to the target client	·         Cross-Client Tables: Imported and can be overwritten with same key. ·         Client-Dependent Tables: Imported and can be overwritten.

*NOTE: Client Dependent Tables are tables with MANDT field and any changes in the table will impact only one Client while Client Independent Tables are also called Cross Client Table which does not have MANDT field and hence any changes will impact all the clients in the server.

Preface – This post is part of the ABAP Beginner series.

Size Category of Database Tables

In Data Class we have defined the kind of Data we are going to have for our table. Now, it’s time to decide the expected Volume of Data. We do it via Size Category of Database Tables.

Initially Every Table receives equal amount of allowed space. If the data exceeds the initial space provided then an extent of memory is provided to the table, the amount of extended memory will depend upon the size category we provide.

In this way we actually prevent creation of Large extended memory and thus reduce the wastage of data base space.

Definition

Initially every table have some memory allotted. Size Category tells us the amount of space that will be extended after the initial memory is filled.

What will happen if extended memory created is also filled?

Then a new extend will be created again with the memory equal to the size category provided as shown below:

How Multiple Extends affects the Data base?

A table with multiple extensions affects database in following ways:

• Decreases System Performance: Data will be fetched from two different sources.
• Increases Database management: Database Reorganization is required
• Lowers Systems Availability: For Database reorganization, it is taken offline.

TYPES OF SIZE CATEGORY

 

Size Category	Expected Rows
0	0 to 1,000
1	1,000 to 4,200
2	4,200 to 17,000
3	17,000 to 68,000
4	68,000 to 270,000
5	270,000 to 540,000
6	540,000 to 1,000,000
7	1,000,000 to 2,100,000
8	2,100,000 to 4,300,000
9	4,300,000 to 170,000,000

 

Preface – This post is part of the ABAP Beginner series.

Data Class in ABAP

Data Class in ABAP is assigned to a table in its Technical Settings. SAP was smart while creating properties for tables. With the help of Data Class it divides the Tables according to their type of Data. It keeps all Master Data together, all Transaction Data together, all User Data together and all Organizational Data together.

Definition:

A Data Class represents a physical area in Data Base where all the Data of the table assigned to this Data Class are stored.

TYPES OF DATA CLASS:

 

DATA CLASS	TYPE OF DATA	DESCRIPTION
APPL0	Master Data	Data that doesn’t changes frequently. e.g. Your Name, Your Employee ID, Your Student ID
APPL1	Transaction Data	Data that changes frequently. e.g. Number of Products on Amazon, Value of Bitcoin
APPL2	Organizational Data	Customizing Data which is defined during System Installation and that doesn’t changes frequently. e.g. Country Codes.
USR & USR1	User Data	Data Class only for user Development.

 

*NOTE: Customizing Data is the data that describes the behavior of SAP environment for particular module.

e.g.  Country Codes, types of Reimbursement Expenses, working hours of Employees.