topic Re: Views in Application Development and Automation Discussions

Views

Former Member — Mon, 11 Aug 2008 06:00:59 GMT

Hi experts,

What is the need of creating views.

projection view.

What are the advantages.

Thank you.

Re: Views

Former Member — Mon, 11 Aug 2008 06:07:01 GMT

Go through the link given below :

With Regards

Nikunj shah

Re: Views

Former Member — Mon, 11 Aug 2008 06:09:58 GMT

Hi Praveen,

Projection let u hide field of only one table

you can use views for a number of reasons in abap

database views can be used in the same way as tables.

Maintenance views can be used for generating different maintaining in sm30 for your table..

there are four options in maintainnec views like :-

read only

read and change

read ,change, delete and insert

read and change(time-specific)

help views are used for search helps.

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

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

Database views should be created if want to select logically connected data from different tables simultaneously.

Database views implement an inner join.

Application programs can access the data of a database view using the database interface. (Just as we write select queries on database tables, we can write them for views as well.)

Includes in Database Views

An entire table can be included in a database view. In this case all the fields of the included table will become fields of the view (whereby you can explicitly exclude certain fields).

To include one of the tables in the view, enter character * in field View field, the name of the table to be included in field Table and character * again in field Field name on the View fields tab page of the maintenance screen of the view.

You can also exclude individual fields of an included table. If you do not want to include a field of the included table in the view, enter - in field View field, the name of the included table in field Table and the name of the field to be excluded in field Field name.

Inserts with Database Views

If a database view contains only one single table, data can be inserted in this table with the view .

You have the following options for the contents of the table fields not contained in the view:

If the field is defined on the database with NOT NULL as initial value, the field is filled with the corresponding initial value.

If the field is defined on the database as NOT NULL without initial value, an insert is not possible. This results in a database error.

If the field is not defined on the database as NOT NULL, there will be a NULL value in this field.

A maintenance view permits you to maintain the data of an application object together.

The maintenance status determines which accesses to the data of the underlying tables are possible with the maintenance view.

Read only: Data can only be read through the view.

Read, change, delete, insert: Data of the tables contained in the view can be

changed, deleted, and inserted through the view.

Read and change: Existing view entries can be changed. However, records

cannot be deleted or inserted.

Read and change (time-dependent views): Only entries whose non-time

dependent part of the key is the same as that of existing entries may be

inserted.

Maintenance View (SE54)

You can use a maintenance view to maintain data, which is distributed over several tables, at the same time.

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.

Regards,

Ranveer.

Re: Views

Former Member — Mon, 11 Aug 2008 06:20:45 GMT

Hi,

Views are created to achieve the same functionality of JION in datafetch operation without using complex code.

for details in views and how to create it chek,

http://help.sap.com/saphelp_webas630/helpdata/en/a8/695a3e740be946e10000000a114084/content.htm

Regards,

Anirban

Re: Views

Former Member — Mon, 11 Aug 2008 06:26:30 GMT

hi,

Refer to the link.

http://help.sap.com/saphelp_nw70/helpdata/en/cf/21ecc5446011d189700000e8322d00/content.htm

http://help.sap.com/saphelp_nw70/helpdata/en/cf/21ed20446011d189700000e8322d00/content.htm

Regards

Sumit Agarwal

Re: Views

Former Member — Mon, 11 Aug 2008 06:59:11 GMT

Pls find below link for the same.

For views Information.

http://help.sap.com/saphelp_40b/helpdata/en/cf/21ec5d446011d189700000e8322d00/content.htm

For Projection Views

http://help.sap.com/saphelp_40b/helpdata/en/cf/21ecc5446011d189700000e8322d00/content.htm

Hope this helps.

Regards,

Re: Views

Former Member — Mon, 11 Aug 2008 08:18:20 GMT

Hi Praveen,

You will find this links helpfull:

http://abapdictionary.blogspot.com/2007/11/abap-views.html

Regards,

Prashant.

Re: Views

Former Member — Mon, 11 Aug 2008 11:08:53 GMT

hi,

Data for an application object is often distributed on several database tables. Database systems therefore provide you with a way of defining application-specific views on data in several tables. These are called views.

Data from several tables can be combined in a meaningful way using a view (join). You can also hide information that is of no interest to you (projection) or only display those data records that satisfy certain conditions (selection).

The data of a view can be displayed exactly like the data of a table in the extended table maintenance.

Given two tables TABA and TABB. Table TABA contains 2 entries and table TABB 4 entries.

The tables are first appended to one another. This results in the cross-product of the two tables, in which each record of TABA is combined with each record of TABB.

Usually the entire cross-product is not a meaningful selection. You should therefore limit the cross-product with a join condition. The join condition describes how the records of the two tables are related.

In our example, Field 3 of TABB identifies Field 1 of TABA. The join condition is then:

TABA - Field 1 = TABB - Field 3

With this join condition, all the records whose entry in Field 1 is not identical to the entry in Field 3 are removed from the cross product. The column for Field 3 in the view is therefore unnecessary.

STRUCTURE OF A VIEW:

Often some of the fields of the tables involved in a view are of no interest. You can explicitly define the set of fields to be included in the view (projection).

The set of records that can be displayed with the view can be further restricted with a selection condition.

In our example, only those records with value 'A' in Field 4 should be displayed with the view.

A selection condition therefore can also be formulated with a field that is not contained in the view.

The join conditions can also be derived from the existing foreign key relationships. Copying the join conditions from the existing foreign keys is supported in the maintenance transaction.

The field names of the underlying table fields are normally used as field names in the view. However, you can also choose a different field name. This is necessary for instance if two fields with the same name are to be copied to the view from different tables. In this case you must choose a different name for one of the two fields in the view.

Selection with a database view, however, is usually more efficient than selection with a nested SELECT statement.

As of Release 4.0 you can formulate the join condition directly in OPEN SQL.

A view has type character and can be accessed in programs like all other types and can be used to define data objects.

DATA BASE VIEWS:

A database view is defined in the ABAP Dictionary and automatically created on the database during activation. Accesses to a database view are passed directly to the database from the database interface. The database software performs the data selection.

If the definition of a database view is changed in the ABAP Dictionary, the view created on the database must be adjusted to this change. Since a view does not contain any data, this adjustment is made by deleting the old view definition and creating the view again in the ABAP Dictionary with its new definition.

The maintenance status defines whether you can only read with the view or whether you can also write with it. If a database view was defined with more than one table, this view must be read only.

The data read with a database view can be buffered. View data is buffered analogously to tables. The technical settings of a database view control whether the view data may be buffered and how this should be done. The same settings (buffering types) can be used here as for table buffering. The buffered view data is invalidated when the data in one of the base tables of the view changes.

INCLUDES IN DATA BASE VIEWS:

You can include entire tables in database views. In this case all the fields of the included table become fields of the view (whereby you can explicitly exclude certain fields). If new fields are included in the table or existing fields are deleted, the view is automatically adjusted to this change. A new or deleted field is therefore automatically included in the view or deleted from it.

If an append structure is added to a table included in a view, the fields added with the append structure are automatically included in the view.

To include a table in a view, you must enter the character '' in field View field in the view maintenance, the name of the table to be included in the field Table and the character '' again in the field Field name.

If you do not want to insert a field of the included table in the view, you must enter a '-' in field View field, the name of the included table in field Table and the name of the field to be excluded in field Field name.

As of Release 4.6C, fields of the base tables of a database view can be included in the view without modifications using an append view. This is analogous to enhancing a table using an append structure. An append view is assigned to exactly one database view. But more than one append view can be created for a database view.

MAINTENANCE VIEWS:

Data that is distributed on more than one table often forms a logical unit, called an application object. You should be able to display, change and create the data of such an application object together. Users usually are not interested in the technical implementation of the application object, such as the distribution of the data on several tables.

You can maintain complex application objects in a simple way using a maintenance view. The data is automatically distributed on the underlying database tables.

All the tables used in a maintenance view must be linked with a foreign key. This means that the join conditions are always derived from the foreign key in the maintenance view. You cannot enter the join conditions directly as in a database view.

A maintenance interface with which the data of the view can be displayed, changed and created must be generated from the definition of a maintenance view in the ABAP Dictionary.

When the maintenance interface is created, function modules that distribute the data maintained with the view on the underlying tables are automatically generated.

The maintenance interface is generated with the Transaction Generate Table View (Transaction SE54) or from the view maintenance screen with Utilities -> Tab.maint.generator.

cheers

fareed

Re: Views

Former Member — Mon, 11 Aug 2008 11:22:33 GMT

Dear,

Projection views are used to mask out certain fields of 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 only refer to one table. Selection conditions cannot be specified for projection views.

There is no corresponding object on the database for a projection view. Access to a projection view is mapped by the R/3 System onto the corresponding access to its base table.

It is also possible to access pooled tables or cluster tables with a projection view.

In an INSERT with a projection view, the fields which were masked out are supplied with their initial values, thus avoiding NULL values.

for more detail u can go through this link....

http://help.sap.com/saphelp_40b/helpdata/en/cf/21ecc5446011d189700000e8322d00/content.htm

Thanks ,

Jaten

Re: Views

former_member206439 — Tue, 12 Aug 2008 04:19:33 GMT

Data for an application object is often distributed on several database tables. Database systems therefore provide you with a way of defining application-specific views on the data contained in several tables. These are called views.

Projection views are used to hide fields of a table. This can minimize interfaces; for example when you access the database, you only read and write the field contents actually needed

Sometimes some of the fields of the tables involved in a view are not of interest. The set of fields used in the view can be defined explicitly (projection).