VIEW's

[Former Member]

Hi All,

1. What is dataelement and domain.

2.what is view and why we create views.

Thanks

srinivas

[Former Member]

Hi,

A data element describes either an elementary type or a reference type.

An elementary type is defined by the built-in data type, length and possibly the number of decimal places.

These type attributes can either be defined directly in the data element or copied from a domain.

A reference type defines the types of reference variables in ABAP programs.

You can use a data element to define the type of a table field, structure component or the row type

of a table type. A data element can also be referenced in ABAP programs with TYPE. As a result, variables

that take on the attributes of a data element can be defined in an ABAP program.

Information about the meaning of a table field or structure component and information about editing the

corresponding screen field can be assigned to a data element. This information is automatically available

to all screen fields that refer to the data element.

This information includes the display of the field in input templates using key word text, column headers

for list output of the table contents (see Field Labels ), and output editing using parameter IDs.

Domain:

A domain defines a value range. A domain is assigned to a data element. All table fields or structure components

that use this data element then have the value range defined by the domain. The relationship between the field or

component and the domain is thus defined by the data element of the field or component.

Fields or components that refer to the same domain (with the assigned data elements) are also changed when the domain

is changed. This ensures that the value ranges of these fields or components are consistent. Fields or components that

are technically the same can thus be combined with a reference to the same domain.

The value range of a domain is defined by specifying a data type and length (and number of decimal places for

numeric data types).

A personnel number is defined by the data format NUMC and by specifying the number of places for this personnel number.

The value range of a domain can be restricted by defining fixed values. If all the fields or components that refer to the

domain should be checked against a certain table, this table can be defined as the value table of the domain.

Output attributes can also be defined for all the fields or components that refer to the domain (see Creating Domains).

A conversion routine can be assigned to a domain. This conversion routine converts values from display format to internal

format for the fields or components that refer to this domain.

Views:

Data about an application object is often distributed on several tables. By defining a view, you can define an

application-dependent view that combines this data. The structure of such a view is defined by specifying the tables

and fields used in the view. Fields that are not required can be hidden, thereby minimizing interfaces. A view can be

used in ABAP programs for data selection.

The data of a view is derived from one or more tables, but not stored physically. The simplest form of deriving data

is to mask out one or more fields from a base table (projection) or to include only certain entries of a base table in

the view (selection). More complicated views can comprise several base tables, the individual tables being linked with

a relational join operation. See also Join, Projection and Selection.

The base tables of the view must be selected in the first step of a view definition. In the second step, these tables

must be linked by defining the join conditions. It is also possible to use the join condition from a foreign key defined

between the tables (see Foreign Key Relationship and Join Condition). In the third step, you must select the fields of the

base tables to be used in the view. Selection conditions that restrict the records in the view can be formulated in the

fourth step.

Four different view types are supported. These differ in the way in which the view is implemented and in the methods

permitted for accessing the view data.

Database views are implemented with an equivalent view on the database.

Projection views are used to hide fields of a table (only projection).

Help views can be used as selection method in search helps.

Maintenance views permit you to maintain the data distributed on several tables for one application object at one time.

Database views implement an inner join. The other view types implement an outer join (see Inner and Outer Join).

The join conditions for database views can be formulated using equality relationships between any base fields.

The join conditions for the other view types must be obtained from existing foreign keys. Tables therefore can only be

combined in a maintenance view or help view if they are linked to one another with foreign keys.

The maintenance status defines whether you can only read data with the view or whether you can also insert and change data

with it.

with regards,

sowjanyagosala.

[Former Member]

A view is a logical view on one or more tables, that is, a view is not actually physically stored, instead being derived from one or more other tables.

In the simplest case, this derivation process can involve simply suppressing the display of one or more fields from a table (projection) or transferring only certain records from a table to the view (selection). More complicated views can be assembled from several tables, with individual tables being linked using the relational join operation.

Types of view

Database view,Projection view,Maintenance view,Help view

- Database View (SE11)

Database views are implement an inner join, that is, only records of the primary table (selected via the join operation) for which the corresponding records of the secondary tables also exist are fetched. Inconsistencies between primary and secondary table could, therefore, lead to a reduced selection set.

In database views, the join conditions can be formulated using equality relationships between any base fields. In the other types of view, they must be taken from existing foreign keys. That is, tables can only be collected in a maintenance or help view if they are linked to one another via foreign keys.

- Help View ( SE54)

Help views are used to output additional information when the online help system is called.

When the F4 button is pressed for a screen field, a check is first made on whether a matchcode is defined for this field. If this is not the case, the help view is displayed in which the check table of the field is the primary table. Thus, for each table no more than one help view can be created, that is, a table can only be primary table in at most one help view.

- Projection View

Projection views are used to suppress or mask certain fields in a table (projection), thus minimizing the number of interfaces. This means that only the data that is actually required is exchanged when the database is accessed.

A projection view can draw upon only one table. Selection conditions cannot be specified for projection views.

- Maintenance View ( SE54 )

Maintenance views enable a business-oriented approach to looking at data, while at the same time, making it possible to maintain the data involved. Data from several tables can be summarized in a maintenance view and maintained collectively via this view. That is, the data is entered via the view and then distributed to the underlying tables by the system.

Reward if useful

[Former Member]

Domains:

Domain is the central object for describing the technical characteristics of an attribute of an business objects. It describes the value range of the field.

Data Element:

It is used to describe the semantic definition of the table fields like description the field. Data element describes how a field can be displayed to end-user.

Domain is stored in DD01L table

Data elements is stored in DD04L table