Post from: http://blog.itpub.net/post/38171/480475original author Gavin sap abap pa certification training notes Part 1
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The client represents a virtual organization and is divided into two types:
Customizing is divided into two parts:
The repository objects are all cross-client objects.
Asap roadmap (SAP configuration roadmap)
1.The basis module first configures the online system
2.Configuration by module consultant (such as mm and SD)
3.When additional features need to be developed, the ABAP personnel conduct development
Three Development Methods
1. Customer DevelopmentIndependent Development(Recommended)
2. ExtensionEnhanced Development
3. ModificationsModified Development(It is strongly not recommended, which may cause difficulties for future upgrades)
You can enter the database query conditions on the screen, print the data (list), and display the data to the user.
Each application server has a large shared memory
Each work process has a local buffer,
The local buffer can store some infrequently changed data objects or read-only objects.
Basic Methods of SAP GUI
1.Sap gui for Windows (Advantages:Fast data operation
Disadvantages:Not cross-platform, and the client needs to be installed)
2.Sap gui for Java (Advantages:Cross-platform
Disadvantages:The operation speed is slightly slower than for Windows)
3.Sap gui for HTML (Advantages:0 installation, easy to view a small amount of data
Disadvantages:High requirements on network transmission and slow speed)
SAP basis database layer (database layer)
The local buffer has a table buffer.
You can add tables that do not change frequently to table buffer.
Communication between systems
Multiple dispatcher communication management by Message Server
Gateways manage communications between multiple systems
Instance instances cannot communicate directlyCommunication through dispather and Ms
Possession and release
Connection between ABAP and database
ABAP does not need to connect to the database by itself, which is different from the Java language.
After each worker process starts, it is connected to the database.
Long transaction run:
When a user occupies multiple processes and executes long-running ABAP program (Long Run Time program example: an endless loop Program), other users can only use a few remaining processes, this will cause most users to wait, and the speed will be very slow,
Solution:The basis personnel can operate or delete users that occupy multiple processes to release threads and relieve the running pressure.
Background processing (background process)
Features:You cannot manually control the check. For example, the system automatically checks the check at AM.
1.Two servers, dialog server and background processing server, are configured respectively.
2.DWP in DS inserts a job into scheduling table (calendar) in the database and sets the background thread task.
3.In BPS, DWP regularly queries the scheduling table cyclically (60 s by default). When a new background task is found, the task is transferred to BWP in bps.
4.BWP operates the database according to the task
The SWP-print process can be configured or not configured, but a DWP needs to be configured.
1.You can click the print button to send a print request (the data is encoded in a recognizable way)
2.DWP puts the print request into the spool request-print queue (which can be database/File System)
(Data can be identified in encoding Mode)
3.SWP searches for print tasks in the queue at intervals. When a new print task is found, the print task is executed.
4.The print task can be sent to the local operating system spool (operating system printing thread) for printing, or printed on a remote printer through the network (for example: printers in the boss's office can remotely print reports. (Data is an unrecognized binary code)
Lock admistration Lock Mechanism
EWP can be matched or not matchedDWP is required. If this server is configured, it is called a lock server.
1.Use su3 to operate the user master data (the system has locked the user master data of the database)
2.New sessionWhen su3 is used, the user data cannot be accessed and modified because the master data has been locked.
The EWP locks the objects corresponding to the table in the memory.
You can customize locks.
Shared lock (read lock)
Incompatible reading/writing at the same time
As long as the user exclusive does not allow any operation (add, delete, modify, query)
Note: If the Lock Object is activated, the system will automatically generate two function module locking methods and unlock
Enqueue (LOCK)Dequeue (unlock)
The dialog server must be attached to a locked server for locking.
To pass the leadership
Locking is to lock the objects in the table in the memory, and lock the database by locking the memory.
The objective is to lock the database.
Principle: cable TV uses the cable TV transmission gap for Network Transmission
DWP processing process
When you click a button, you may execute one or more ABAP programs and may have one or more requests.
The program may be in a series. After the first program is completed, the second program runs, but the program also needs to be put into the queue and wait for the idle thread.
Only when all programs or requests are executed can the results be displayed.
PbO: Process before output
Pai: Process after input
The ABAP screen will trigger two events before the pop-up time.PbOAnd Pai
To process an event, you need to add the corresponding code for implementation.
Event trigger mechanismTrigger
The code block written for the event is called the event block.
Note: The same programThe screen number cannot be repeated.
PbO Pai before and after a screen may not be in the same DWP. Due to the time relationship, the system may divide them into different DWP, but it gives users a smooth feeling.
Enterprise Structure: Enterprise Architecture
Logical size order:
Client> company code> plant> sales organization> division> storage locations
Client (Group) representative Enterprise
All branches of an enterprise have the company code.
Production in subordinate factories
Note: before the system goes online, all organizations must be configured in R/3.
Customer master customer master data
General data public data
Financial Accounting DataFinancial Information
Finished semi-finished products in SAP are considered Materials
There are three types:
1.Immediately create an invoice immediately when creating an order
3.Next selection run or at a specified time create an invoice at a specified time
Message Type message types include:
View invoice on screen
On the printer
Fax an invoice
Send an invoice via email
EDI electronic data exchange
Business workflow Workflow
1.Employees need to make an appointmentEnter the reservation application on your computer
2.Process the reservation application on the supervisor's computer through the workflow and make a decision on whether to approve the application.
3.Workflow ended after approval
4.If the rejected application is not approved, the application will be sent to the employee and further decision-making is required. Do you need to modify the application form again or stop the workflow without modifying the application form?
5.If the application form is modified again, the superior will obtain the application form again. If the application form is approved, the workflow ends.
Business scenario scenarios
Use scenarios to interpret workflows
ABAP program process---- Main business scenario
Sap abap must have business scenarios
Airport Business Model sap flight date Model
Departure airportDeparture airport
Destination Airport destination airport
Basic Requirements for ticket booking for travel agents or travel agencies:
At a specific time to a specified location
Process specific flight booking
Very important: flight model table:
Scarr airline table
Spfli route table
Sflight flight schedule (required during ticket booking)
The relationship between the above tables is a tree relationship.
One airline corresponds to multiple routes, and one route corresponds to multiple flights
Work Process can execute abapprogram
The application server is split into two parts:
1.Some Java programs can be executed.
2.The other part is the ABAP program.
Black box Black Box
For GUI and user, it is equivalent to a black box
View for the user User View
Screen standard screen: standard screenDynproDynimic: FunctionUser input, in order to insert a database,
Selection screen: function: query the database based on the conditions entered by the user (generally)
List function: displays data to users.(Important: Every ABAP programmer must master)
Interaction between server Layers
Interaction between two layers on the server
When the ABAP program starts, it needs to execute the program in WP.
The same program is divided into different blocks
Start of Screen
All the repository of ABAP is stored in the database.
When defining the screen selection, the added screen fields are defined according to the fields in the data dictionary.
Therefore, you need to check which type of field is required from the repository before the definition.
Both the screen memory and the field variables on the hard disk correspond to the same
But the storage location is different.
In a program, you can use the variables in the memory as database conditions and use the where statement for database operations.
Then the database returns the result set to the ABAP program, and finally to the list screen.
The program can regard memory variables as conditions.
Important: in the new version, development classes