What are the basic objects in abap dictionary ?

Hi satyam,

The basic objects of the ABAP DICTONARY are

1.DATABASE TABLE

2.VIEW

3.DATA TYPE

4.TYPE GROUP

5.DOMAIN

6.SEARCH HELP

7.LOCK OBJECT

Award points if helpful.

Kiran Kumar.G.A

Hi Satyam,

Check this link..

http://help.sap.com/saphelp_webas620/helpdata/en/cf/21ea31446011d189700000e8322d00/content.htm

The DDIC is nothing but the ABAP Dictionary. The ABAP Dictionary centrally describes and manages all the data definitions used in the system.

Data types

Data types are the actual type definitions in the ABAP Dictionary. They allow you to define elementary types, reference types, and complex types that are visible globally in the system. The data types of database tables are a subset of all possible types, namely flat structures.

Data Elements

Data elements in the ABAP Dictionary describe individual fields. They are the smallest indivisible units of the complex types described below, and are used to specify the types of columns in the database. Data elements can be elementary types or reference types.

Structures

A structure is a sequence of any other data types from the ABAP Dictionary, that is, data elements, structures, table types, or database tables. When you create a structure in the ABAP Dictionary, each component must have a name and a data type. In an ABAP program, you can use the TYPE addition to refer directly to a structure.

If you define a local data type in a program by referring to a structure as follows:

TYPES <t> TYPE <structure>.

Table Types

Table types are construction blueprints for internal tables that are stored in the ABAP Dictionary.

When you create a table type in the ABAP Dictionary, you specify the line type, access type, and key. The line type can be any data type from the ABAP Dictionary, that is, a data element, a structure, a table type, or the type of a database table. You can also enter a predefined Dictionary type directly as the line type, in the same way that you can with a domain.

Type Groups

Before Release 4.5A, it was not possible to define standalone types in the ABAP Dictionary to which you could refer using a TYPE addition in an ABAP program. It was only possible to refer SAP AG BC - ABAP Programming

Data Types in the ABAP Dictionary to flat structures. Structures in programs corresponded to the structures of database tables or structures in the ABAP Dictionary. In ABAP programs, you could only refer to database tables and structures in the ABAP Dictionary using LIKE. It was, however, possible to refer to individual components of the Dictionary type. Complex local data types such as internal tables or deep structures had no equivalent in the ABAP Dictionary. The solution to this from Release 3.0 onwards was to use type groups. Type groups were based on the include technique, and allowed you to store any type definitions globally in the Dictionary by defining them using TYPES statements.

Views:

There are 4 types views are avilable in SAP.

Database View - To club more than one table

Projection View - To hide fields in one table

Maintanance View - To maintain database records in table

Help View - To provide help for a fields (Same functionality as Search help. This is outdated)

View are improves perfromance in the following aspects

1. If you want to use more than two table in 'JOIN' condition better to use Views . It will improves performance of a program

2. If you want to use mutiple FOR ALL ENTRIES clause, better to club all SELECT statement in a view.

Lock Objects:

Lock objects are use in SAP to avoid the inconsistancy at the time of data is being insert/change into database.

SAP Provide three type of Lock objects.

Read Lock(Shared Locked)

protects read access to an object. The read lock allows other transactions read access but not write access to

the locked area of the table

Write Lock(exclusive lock)

protects write access to an object. The write lock allows other transactions neither read nor write access to

the locked area of the table.

Enhanced write lock (exclusive lock without cumulating)

works like a write lock except that the enhanced write lock also protects from further accesses from the

same transaction.

You can create a lock on a object of SAP thorugh transaction SE11 and enter any meaningful name start with EZ Example EZTEST_LOCK.

Use: you can see in almost all transaction when you are open an object in Change mode SAP could not allow to any other user to open the same object in change mode.

Example: in HR when we are enter a personal number in master data maintainance screen SAP can't allow to any other user to use same personal number for changes.

Technicaly:

When you create a lock object System automatically creat two function module.

1. ENQUEUE_<Lockobject name>. to insert the object in a queue.

2. DEQUEUE_<Lockobject name>. To remove the object is being queued through above FM.

You have to use these function module in your program.

Search Helps:

These are two types.

Elementary n Collective.

1) Elementary search helps describe a search path. The elementary search help must define where the data of the hit list should be read from (selection method), how the exchange of values between the screen template and selection method is implemented (interface of the search help) and how the online input help should be defined (online behavior of the search help).

2) Collective search helps combine several elementary search helps. A collective search help thus can offer several alternative search paths.

3)An elementary search help defines the standard flow of an input help.

4) A collective search help combines several elementary search helps. The user can thus choose one of several alternative search paths with a collective search help.

5)A collective search help comprises several elementary search helps. It combines all the search paths that are meaningful for a field.

6)Both elementary search helps and other search helps can be included in a collective search help. If other collective search helps are contained in a collective search help, they are expanded to the level of the elementary search helps when the input help is called.

See the below link to understand this completely:

http://help.sap.com/saphelp_nw2004s/helpdata/en/cf/21ee93446011d189700000e8322d00/frameset.htm

Rewards if useful

hi satyam,

The basic elements are :

->tables

->data elements

->structures

->domains

Tables:

In the abap/4 dictionary,tables can be defined in a way,which is not database dependent.for this,fields of the table are defined with their database-independent data-types and lengths.when table is activated,a physical table definition in the database is added to the table definition stored in abap dictionary.the minimum set of fields sufficient to uniquely identify each table line by their values is termed as key.

The technical settings allow u to optimize space requirements and table access behaviour for database tables.

The most important parameters in technical settings are:

Data class:the data class establishes the physical area of the database in which ur table is to be stored.

Size category: the size category will allow to specify estimated space requirements for the table in the database.

Data element:

To create a field you need a data element. The data element contains the field labels and online documentation (also called F1 help) for the field. It is purely descriptive; it contains the semantic characteristics for the field, also known as the "business context." The labels you provide within a data element will be displayed on the screen beside an input field. The data element also contains documentation that is displayed when the user asks for help on that field by pressing the

F1 key.

Domain:

A data element's definition requires a domain (see Figure 3.5). The domain contains the technical characteristics of a field, such as the field length and data type. Domains and data elements are reusable. A domain can be used in more than one data element, and a data element can be used in more than one field and in more than one table.

For example, assume you need to design a customer information table called zcust that must contain work, fax, and home telephone numbers

To create a field, you usually start by creating a domain for it. In this case, you might create a generic telephone number domain, name it zphone and give it a data type of CHAR and a length of 12. This would be a generic telephone number domain; most types of telephone numbers could be stored using this domain. As such, it can be used to define specific types of telephone numbers, such as fax or home telephone numbers.

After creating the domain to hold the purely technical description of a field, you then create a data element to hold the descriptive attributes of the field. In the data element you must enter the name of a domain to give it technical characteristics. Then, you enter the labels and documentation (F1 help) to describe the data you will store. In this example, you would probably create three data elements, one for each of the home, work, and fax telephone numbers. In each data element, you would enter field labels describing the type of telephone number you will store with it, and the F1 help for the end-user.

Having created the data elements, you can now create the table. You could create three phone number fields in the table (home, work, and fax) and assign the corresponding data element to each field. A data element is assigned to each field. This gives the field descriptive information from the data element and technical information from the domain that it references. When the field is used on a screen, it obtains a label and F1 help documentation from the data element, and its length and data type form the domain within the data element.

Structures:

In the abap/4 dictionary the construction of the data produced when calculations are carried out within programs or when data is transferred between programs can also be defined globally.

Structures are defined in almost the same way as tables.the only difference is that no database table is generated.the same data elemnts and domains can be used in sturcturs as in tables.

U can download the book,sams teach yourself abap in 21 days from google.it is very helpful

Refer to these links:

http://help.sap.com/saphelp_nw70/helpdata/en/fc/eb3138358411d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_nw70/helpdata/en/cf/21ea0b446011d189700000e8322d00/frameset.htm

regards,

sravanthi.

Hi,

BASIC OBJECTS

- Tables

- Domains

- Data elements

- Structures

- Foreign keys

AGGREGATE OBJECTS

- Views

- Matchcodes

- Lock objects

Regards

Madhu

hi,

basic objects in abap dictionary are

Tables

Domains

Data elements

Structures

Foreign Keys

and aggeregate objects are

Views

Match Code.

Lock Object.

regards

rajasekhar

Hi Satyam,

1.DATABASE TABLE

2.VIEW

3.DATA TYPE

4.TYPE GROUP

5.DOMAIN

6.SEARCH HELP

7.LOCK OBJECT

DATABASE TABLE :

Form of display for data in a relational database. The columns or database fields of the database tables in the SAP System are defined in the ABAP Dictionary. Each database table has a unique primary index and can have additional secondary indexes. Foreign currency relationships can exist between the individual database tables.

VIEWS:

They have structure as a table.They are referenced to a table.But they dont hold data.

DATA TYPE:

The data types are predefined by the C/C++ precompiler.It defines the kind of data that the data element would hold.

DOMAIN:

Domain definitions enable ranges of values to be defined and designated for table columns.

Each value range definition has a name that is unique within the overall database system.

If a domain was defined without an owner, the catalog sections (part catalogs) are searched in the following order to locate the specified value range:

Catalog part of the current owner

Catalog part of the DBA who created the current user

Catalog part of the SYSDBA

SEARCH HELP:

Search helps enable you to restrict selections using a variety of criteria. They are particularly useful if you want to report on data for persons for whom the information at your disposal is incomplete. If you choose Search helps, the system displays a variety of search helps (such as last name – first name and organizational assignment) which can be used to select personnel numbers efficiently.

After you have selected the search help for which you have the most information, enter the information. When the report is executed, it only runs for the employees who meet the criteria specified.

The Search helps function enhances the search helps included in the selection screen with the employee’s application number, system user name, and free search search helps, for example. PDC error indicator and payroll correction run are also important search helps. These search helps enable you to select personnel numbers for which errors occurred when a time evaluation report or payroll run was executed.

LOCK OBJECTS:

The R/3 System synchronizes simultaneous access of several users to the same data records with a lock mechanism. When interactive transactions are programmed, locks are set and released by calling function modules (see Function Modules for Lock Requests). These function modules are automatically generated from the definition of lock objects in the ABAP Dictionary.

Basic Objects of ABAP Dictionary:

1.tables

2.Data elements

3.Domain.

Cheers,

Hakim

Hi murthy,

BASIC OBJECTS are

1.Tables 2.Domains 3.Data elements 4.Structures 5.Foreign keys

AGGREGATE OBJECTS

1.Views 2.Matchcodes 3.Lock objects

Regards

prabhushankar.b