what is data base view, projection view

[Former Member]

hi

experts

please answer me

what is data base view, projection view

[Former Member]

Hi

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.

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.

[Former Member]

hi,

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.

A projection view contains exactly one table. You cannot define selection conditions for projection

views.

There is no corresponding object in the database for a projection view. The R/3 System maps the

access to a projection view to the corresponding access to its base table. You can also access

pooled tables and cluster tables with a projection view.

Data about an application object is often distributed on several database tables. A database view

provides an application-specific view on such distributed data.

Database views are defined in the ABAP Dictionary. A database view is automatically created in

the underlying database when it is activated.

Application programs can access the data of a database view using the database interface. You

can access the data in ABAP programs with both OPEN SQL and NATIVE SQL. However, the

data is actually selected in the database. Since the join operation is executed in the database in

this case, you can minimize the number of database accesses in this way. Database views

implement an inner join

[Former Member]

Hi Naresh,

The main concept of view is to combine several fields of two or more tables or it can be done within single table. See below for clear explanatioin between the Database View and Projection View.

DATABASE VIEW:

The database view is combining several fields of two or more tables into single table.

For example: Consider three tables T1,T2 and T3.

Fields of T1 are F1,F2 and F3.

Fields of T2 are F1,F5.

By using a Database view u can combine the fields of both T1 and T2 provided primary and foreign key relation is maintained between the two tables and final view can have fields like

F1,F2,F3,F5.

PROJECTION VIEW:

First will say the difference between projection and database view which is nothing but for projection view, view is maintained only in one table but in database view, view is maintained between 2 or more tables. Here single table view is not allowed

For projection view, view is maintained within a single table.

For example,if Table T1 has fields F1,F2,F3,F4,F5.

After projection view, view will look like F1,F2,F5.

Award points if useful.

Thanks,

Karthik

[Former Member]

Hi Dude,

DB View:

The database view is the only type of view in SAP that is physically created at the database level. In other words, the underlying database system also directly recognises the view, apart from SAP. Therefore, database views must be created over transparent tables.

With the database view, all three of the relational operations (projection, selection, and join) can be used.

Database views can be buffered just like transparent tables. In the technical settings you can decide whether to have buffering off, or on with type single record, generic, or full.

Can be built over many tables

Data can be updated if the view is built over a single table

Data updates can use open SQL or Native SQL

Updates are more efficient than using

a Projection View

Fields in the view can be named differently from the fields in the underlying table(s)

Can be buffered

The projection view is a logical view. In this context, the word “logical” means that the view exists within the ABAP Dictionary but is not recognised by the underlying database system.

Projection views must be defined over a single transparent table.

The only relational operation that is valid for a projection view is projection.

Must be built over a single table

Data can be updated

Data updates must use open SQL

Updates are less efficient than using a Database View

Fields in the view must be named the same as the fields in the

underlying table

Can’t be buffered

Regards,

Lakshmanan

[Former Member]

[Projection View|http://help.sap.com/saphelp_nw70/helpdata/en/cf/21ecc5446011d189700000e8322d00/frameset.htm]

[Database View|http://help.sap.com/saphelp_nw70/helpdata/en/cf/21ecc5446011d189700000e8322d00/frameset.htm]

Regards.

Edited by: Sravan Prakash.V on Feb 20, 2008 3:22 PM

[Former Member]

hi,

Database views are implemented with an equivalent view on the

database.

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

Data about an application object is often distributed on several

database tables. A database view provides an application-specific

view on such distributed data.

Database views are defined in the ABAP Dictionary. A database

view is automatically created in the underlying database when it is

activated.

Application programs can access the data of a database view using

the database interface. You can access the data in ABAP programs

with both OPEN SQL and NATIVE SQL. However, the data is

actually selected in the database. Since the join operation is executed

in the database in this case, you can minimize the number of database

accesses in this way. Database views implement an inner join.

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.

A projection view contains exactly one table. You cannot define

selection conditions for projection views.

There is no corresponding object in the database for a projection

view. The R/3 System maps the access to a projection view to the

corresponding access to its base table. You can also access pooled

tables and cluster tables with a projection view.

regards,

sreelakshmi.

[Former Member]

HI

Hope it will help you.

Reward if help.

The followings are different types of views:

- 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.

Go thru this link plzz

http://help.sap.com/saphelp_nw2004s/helpdata/en/cf/21ecf9446011d189700000e8322d00/frameset.htm

- 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.

Please have a look at below link. It will help you.

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21ed06446011d189700000e8322d00/frameset.htm

for more detailed info look on:

http://www.sap-img.com/abap/what-is-the-different-types-and-usage-of-views.htm

&

https://www.sdn.sap.com/irj/sdn/wiki?path=/display/home/abap+dictionary&;

1.Go to se11

2. select view radiobutton and give a name

3. Create

4. select type of view you want to create. Such as database view.

5. give short description

6. give a table name such as mara

7. press the pushbutton relationship. here you will find all the tables which are allowed to create view with mara.

8. select one or mane tables.

8 copy

9.save , check and activate.

[Former Member]

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