Topic Covered in this Pdf :
- Purpose of ABAP dictionary ?
- What Information is stored in ABAP Dcitionary?
- Integration in the ABAP Development Workbench
- Tables
- Tables Fields
- Assignment of the data Type, Field length and Short text
- Technical Setting
- Data Class
- Size Category
Exercise
Creation Of table
- Field
- Data Element
- Domain
Creation Of view
- Database View
- Projection View
- Maintainance View
- Help View
Creation of Strucutre
- Include
Type of a table or structure
The table type determines how the logical table description defined in
the ABAP/4 Dictionary is reproduced on the database.
There are the following table types:
o transparent table
o structure
o append structure
For internal purposes, such as storing control data or update texts,
there are in addition the following table types:
o pooled table
o cluster table
o generated view structure
structrures in sap
No data records exist in the database for a structure. Structures are
used for the interface definition between programs or between screens and
programs.
Append structure
An append structure defines a set of fields which belong to another table
or structure but which are treated in the correction administration as
its own object.
Append structures are used to support modifications.
sap pooled tables
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.
sap 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
What are ranges? What are number ranges?
It is often necessary to directly access individual records in a data structure. This is done using unique keys. Number ranges are used to assign numbers to individual database records for a commercial object, to complete the key. Such numbers are e.g. order numbers or material master numbers.
What are matchcodes? Describe?
A matchcode is a tool to search for data records in the system. Matchcodes are an efficient and user-friendly search aid for cases where the key of a record is unknown. It consists of two stages one is Match code object and the other is Matchcode ID. A matchcode object describes the set of all possible search paths for a search term. Matchcode ID describes a special search path for a search term.
What is a check table and What is a value table?
The relational data model contains not only tables, but also relationships between tables.
These relationships are defined in the ABAP/4 Dictionary by foreign keys. An important
function of foreign keys is to support data integrity in the relational data model. Foreign
key fields may assume only those values allowed by the check table, in other words,
values occurring in the primary key of the check table.
A foreign key provides a link between two tables, for eg.,T1 and T2 by including a
reference in table T1 to the primary key of table T2. For this purpose, Foreign key fields
assigned to the primary key fields of T2 are included in T1. Table T1, which is the one
being checked, is called a foreign key table, and table T2 is called a check table. The
terms dependent (foreign key) table and referenced (check) table are also used.
VALUE TABLE:If the domain of the check field has a value table, this is proposed by the system as check table in the foreign field maintenance. The key fields of the value table are in this case assigned fields of the foreign key table with the same domain. These
fields may assume only those values allowed by the value table.
The value range of the domain can be defined by specifying value table.All table fields
referring to this domain can then be checked against the corresponding field of this value
table.In order the check can be executed, a foreign key must be defined for the value
table.
What is Table Maintenance Generator . What is use of it?
As all of you know, we can create database tables in SAP using transaction code
SE11. A table can be manipulated by a program or manually.
When creating table, you will find a check box 'Table maintenance allowed'. If we
check that option, we can manually enter entries using SE16 or table
maintenance generator screen.
SE16 is for data browser.
How to create table maintenance generator?
Go to SE11, give the table name and click on change. Then Go to utilities--> Table
maintenance generator.
In the table maintenance generator screen, we should give Authorization Group,
Function Group name (Function Group name can be same as table name),
Maintenance type can be one step or two step, usually we will create with one
step. we should give maintenance screen number. After clicking on create button,
a table maintenance generator will be created.
To check it go to SM30 . In SM30, we find display, Maintain options.
We can view the table contents by choosing Display and we can create table
entries by choosing Maintain.
Why we have to go for Table maintenance generator, when we can edit the table
by SE16 or SE11, utilities->create entries?
In the production system, end-users will not be having access to transaction
codes like SE11 and SE16. Developers will not be having access to many
transaction codes including the above two.
To view the contents of the database table, we will use SE16n in Production
system. Please find out the difference between SE16 and SE16n.
All these authorizations will be maintained by BASIS team, by creating access
profiles.
So in order to edit or create the contents of a database table, we should go for
table maintenance generator. In real time, authorizations will be maintained in
production system. (even in development and Test systems to some extent).
There is an audit like Sarbanes-Oxley Act for American clients, where every thing
will be audited by government agency. To know more about SOX, use the links on
the right hand side of this page.
The second reason is, we can edit or create multiple entries at a time, using table
maintenance generator.
Apart from that we have options like 'Enter conditions' in table maintenance
screen SM30. Please try to find out the use of those, by creating an example.
Table Maintenance generator: Difference between one step and two steps.
While creating table maintenance generator, we find below options:
When we choose one step, we have to give the screen number in Overview Screen field.
When we choose two step, we have to give both overview screen number and single screen number.
You can give any number for screen. Don’t give 1000 screen number. As this
number is reserved for selection screen.
When we choose two step, two screens will be created for table maintenance. For
single step only one screen will be created.
When we choose two step, table maintenance will work as follows
Go to SM30, give the table name for which you have created table maintenance-
Overview screen will be displayed. To create entries, when you click on ‘new
entries’. Another screen will be displayed, where you give input and save. You can
enter one record at a time.
Go to SM30; give table name for which you have created table maintenance-
Overview screen will be displayed; To create entries click on ‘new entries’, you can
enter the records on the same screen. You can enter multiple records at a time.
We use single step generally, as it is user friendly.
To completely understand the difference and above points please do exercise by
creating table maintenance generator in both ways (using single step and two
step).
No comments:
Post a Comment