What is View? How many types of Views are there?
A view is a logical view on one or more tables. A view on one or more tables i.e., thedata from a view is not actually physically stored instead being derived from one ormore tables. A view can be used to summarize data which is distributed amongseveral tables. There are different views ie.,
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 thesecondary tables also exist are fetched. Inconsistencies between primary andsecondary table could, therefore, lead to a reduced selection set.In database views, the join conditions can be formulated using equality relationshipsbetween any base fields. In the other types of view, they must be taken from existingforeign keys. That is, tables can only be collected in maintenance or help view ifthey are linked to one another via foreign keys.
Help View (SE54)
Help views are used to output additional information when the online help system iscalled. 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 inwhich the check table of the field is the primary table. Thus, for each table no morethan one helps view can be created, that is, a table can only be primary table in atmost 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 isactually required is exchanged when the database is accessed.A projection view can draw upon only one table. Selection conditions cannot bespecified for projection views.
Maintenance View (SE54)
Maintenance views enable a business-oriented approach to looking at data, while atthe same time, making it possible to maintain the data involved. Data from severaltables can be summarized in a maintenance view and maintained collectively via thisview. That is, the data is entered via the view and then distributed to the underlyingtables by the system.
A view is a logical view on one or more tables. A view on one or more tables i.e., thedata from a view is not actually physically stored instead being derived from one ormore tables. A view can be used to summarize data which is distributed amongseveral tables. There are different views ie.,
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 thesecondary tables also exist are fetched. Inconsistencies between primary andsecondary table could, therefore, lead to a reduced selection set.In database views, the join conditions can be formulated using equality relationshipsbetween any base fields. In the other types of view, they must be taken from existingforeign keys. That is, tables can only be collected in maintenance or help view ifthey are linked to one another via foreign keys.
Help View (SE54)
Help views are used to output additional information when the online help system iscalled. 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 inwhich the check table of the field is the primary table. Thus, for each table no morethan one helps view can be created, that is, a table can only be primary table in atmost 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 isactually required is exchanged when the database is accessed.A projection view can draw upon only one table. Selection conditions cannot bespecified for projection views.
Maintenance View (SE54)
Maintenance views enable a business-oriented approach to looking at data, while atthe same time, making it possible to maintain the data involved. Data from severaltables can be summarized in a maintenance view and maintained collectively via thisview. That is, the data is entered via the view and then distributed to the underlyingtables by the system.
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