views and create locks

Hi rams,

1. wat r the different types of views and how to create those views

a) Views are created using SE11.

b) basically there are 4 types of views.

c) database view and projection view

(they are based one more than 1 table / 1 table

and can be used in abap programs

in Select * from viewname,

or can be declared in strucgture.

d) other view - maintenance view

is just a bunch of screens

to facilitate data entry in to the table.

(it cannot be used in abap programs

like point no c)

e) last is help view ( ihave not used much)

2.

how ro create locks and wat r the differen types of locks

can u explain me detail pls

LOCK Objects , are created using se11.

regards,

amit m.

hi rams,

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.

- 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

<b>locks</b>

locks are created using transaction se11..

this link has all the informatiion about lock objects

http://help.sap.com/saphelp_nw04/helpdata/en/41/7af4c5a79e11d1950f0000e82de14a/content.htm

<b>reward appropriate points if useful..and close the thread..</b>

Message was edited by: Ashok Kumar Prithiviraj

Hai babu,

There are four types of Views..

<b>Database view

Project

maintaneance

Help</b>

Much info is in this link...

http://www.sappoint.com/abap/ab4dict.pdf

Regards,

Srikanth.

Hi,

read the SAP help

Check the help on Database View

http://help.sap.com/saphelp_nw04/helpdata/en/36/74c0358373003ee10000009b38f839/frameset.htm

Help on Projection view

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21ed20446011d189700000e8322d00/frameset.htm

Help on Maintenace view.

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21ed2d446011d189700000e8322d00/frameset.htm

Help on Help view

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21ed13446011d189700000e8322d00/frameset.htm

regards

vijay

Hi,

Just to add one more point....

When you try to use locks in your programs follow this procedure...

it is always advisable to create an Optimized Lock.

At the time when you really are updating the database entries convert the Optimized lock into exclusive lock.

This will always avoid foriegn lock problems.

Unlike the database, which sets physical locks, the SAP lock mechanism sets logical locks. This means that

A locked database entry is not physically locked in the database table.

The lock entry is merely entered as a lock argument in the central R/3 lock table. The lock argument is made up of the primary key field values for the tables in the lock object. These are import parameters of the enqueue function module. The lock is independent of database LUWs. It is released either implicitly when the database update or the SAP transaction ends, or explicitly, using the corresponding dequeue function module. You can use a special parameter in the update function module to set the exact point at which the lock is released during the database update.

<b>A locked entry does not necessarily have to exist in a database table.

You can, for example, set a lock as a precaution for a database entry that is not written to the database until the update at the end of the SAP LUW</b>.

The effectiveness of the locks depends on cooperative application programming.

Since there are no physical locks in the database tables themselves, all programs that use the same application objects must look in the central table themselves for any locks. There is no mechanism that automatically prevents a program from ignoring the locks in the lock table.

Regards,

Vara