ABAP - Advance Business Application Programming

Sharing nota akak on ABAP lah ye..  kih3 :D

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1.8.1. Introduction to ABAP
=======================

use FIFO (first in first out) method.

work processes:

• task handler
• ABAP/4 interpreter
• screen interpreter
• database interpreter

ABAP WorkBench SE80

• object browser SE80
• ABAP Editor - create program SE38
• Function builder
• screen painter - GUI program SE51
• menu painter - text in menu SE41

SQL Trace 
- performance of program
- tcode ST05
- options:

• SQL trace
• Enqueue trace
• RFC trace
• Table buffer trace

Run Time Analysis
- measures the run time program.
- time take for each stmt
- 3 section of result:

• ABAP
• Database
• System

Program Testing

• unit test
• functional test
• integration test
• regression test

ABAP debugger

• use to execute programs
• execute one by one or as a whole to check the flow.
• breakpoint.

Program type:

• 1-Report - executable programs.
• M-Module Pools - screen logic, must have tcode.
• F-Function Modules
• K-Class Definitions
• J-Interface definitions
• S-Subroutine pools
• I-Include

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1.8.2. Data Types in ABAP
=======================
- 3 Data Types:

• Elementary (fixed - C, N, D, T, variable length - STRING, XTRING)
• Reference (Data, Object References)
• Complex (Structure, table type)

F-From
R-Report
I-Interface
C-Conversion
E-Enchancement
W-Work flow.

PBO - Process Before Output
PAI - Process After Input
Defining:

• predefined (system variables)
• Data Dictionary
• Local Data types - in ABAP programs

TYPE statement

• to define data types
• can use existing data type or created new.

LIKE statement

• to define data types
• copies technical attributes

============================
1.8.3. Controlling Program Flow
============================

- conditional branching:

• if
• case

-unconditional branching:

LOOPS

1. unconditional = DO
2. conditional = WHILE
3. internal table = LOOP
4. dataset = SELECT

Terminating loops:

• continue - unconditional
• chek
• exit

ABAP Program starts:

• REPORT
• PROGRAM

Program Structure

• Declaration Part
• Processing Block

==================
1.8.4. Internal Tables
==================

Type:

1. Standard - referenced to a DB table.
2. Sorted - data sorted when this calles, using INSERT.  use table key.
3. Hashed - hash alghorithm to identify rescord at runtime.

IT (Internal Table) - used for data storage at runtime.
WA (work Area) - store one record at a time.

Populating IT:

• APPEND - by lines
• INSERT .. INTO TABLE, inert WA into IT.

Data Exchange

• Copy/move = MOVE source TO Dest
• Append line = APPEND LINES OF it1 TO it2
• Insert line = INSERT LINES OF ..
• Copy = MOVE ... TO ...

Changing Lines

• copy/move = MOVE ... TO ..
• MODIFY
• WRITE ... TO ...

Summing:
- Calculate totals :  COLLECT ... INTO ...

Initializing:

• Initialize: clear the current data
• Refresh: applies to the body of the table.
• Clear: can clear the content of variables.
• FREE: to release the memory space.

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1.8.5. Data Dictionary
==================

Data elements usage: 

• reusability
• semantic attributes

DOMAINS
define technical attributes
- data type
- length
and value ranges
- fixed
- interval

Tables
- data containers in a relational DB
- components:

• fields
• foreign keys
• technical settings
• indexes

Structures
- sequence of any other data type from ABAP dictionary
- central definition used more than once, can be change centrally.
- 2 ways:

• include structure: into different table.
• append structure: into same table.

Table types:
- SE11
- generate table type.
- range table type.

Views
- logical view on one or more then one table.
- Type:

• Database view: same view as in DB
• Projection view: hide fields of table, one table only.
• Help view: selecttion method in search help.
• Maintenance view.

LOCK Objects
- SAP synchronizes simultaneous access of several users to the same data with lock mechanism.
- lock object: define the lock mechanism for the table.
- structure of lock objects.
- lock arguments : key fields
- lock mode:

• exclusive lock - single user.
• shared lock - more the one user, display only
• exclusive but not cummulative.

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1.8.6. Event and Messages
=======================

Events

• initialization
• at selection-screen output
• at selection-screen on field
• at selection-screenon block
• at selection-screen 
• start-of-selection
• end-of-selection

 interactive events:

• at line-selection
• at user-command
• at pfnn
• top-of-page during line selection

list events:

• top-of-page
• end-of-page

control break events

• at first
• at last
• at new
• at end of
• at change of

messages:

• flow logic stmt
• MESSAGE stmt in ABAP
• error dialog performed by system
• dialog mode
• selection  screens
• messages in a list.

===================
1.8.7.  Open SQL Stmt

===================

LUW - Logical Unit of Work.
- commit work
- rollback work

SQL - Structured Query Language.

Open SQL
- subset of standard SQL fully intergrated in ABAP.
DML - Data Manipulation Language
SELECT, INSERT, UPDATE, & DELETE.

Aggregate Function

• max
• min
• avg
• sum
• count
• count(*)
• group by - group by line statically
• order by - sort by column.

===================
1.8.8. List Processing
===================

Type:

• simple lists
• interactive lists
• ranked list

complex list - user interact up to 20 secondary lists

command: write, uline, skip, new-page.

formatting

• numeric - no-sign, decimals, round, currency
• date - DD/MM/YY, DDMMYY
• all - centered, no zero, no-gap

====================
1.8.9. List Processing 2
====================

checkbox
1 or X = checked
0 or (space) = unchecked.

- vertical line = | or sy-vline
- horizontal line = uline
- blank line = skip
- scroll = scroll list to ...
- outputting fields on hotspot.

===================
1.8.10. Interactive Lists
===================

- basic list
- secondary list
- pop up screen = window
- describe list

sy-subrc 

• 0 OK
• 4 line not exist
• 8 list not exist

- assigning custom GUI statue:

Set pf-status '(status name)'
status name: 20 char & caps letter only

=====================
1.8.11.  Dialog Programs.
=====================

Dialog programs = provide interface to users to enter, change, display or process data.
- starts with SAP tcode.
- components:

• SAP tcode (1- executable, M module)
• Screens (Screen painter, PAI, PBO)
• GUI Status (menu bar, application bar)
• ABAP program

- screens can be called by:

• tcode
• CALL SCREEN stmt

- user action - funtion code is assigned, trigger PAI event.
- screen consists of:

• flow logic
• elements
• attributes
• layout

=========================
1.8.12.  BDC & SAP Scripts
=========================

BDC - Batch Data Communication
Steps:

• analysing transaction
• assign data
• format conversion
• transfer legacy data to SAP

Methods:

• Batch Input (BI)
• Call Transaction (CT)
• Direct Input (DI)

SAP Script
- used to print the form

ABAP Debugger

• static breakpoint
• dynamic breakpoint
• watch point