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data dictionanry

Former Member
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What is data objects ? and what is logical database ?

1 ACCEPTED SOLUTION

Former Member
0 Kudos

Hi Lakshmanan,

<u><b> Logical databases</b></u> are SAP standard programs that are desinged with selections screens that helps easy retrival and access of data from various tables in and efficient manner.

You can get to know more about the logical databases from the SAP documentation or the following links.

A logical database is a special ABAP/4 program which combines the contents of certain database tables. You can link a logical database to an ABAP/4 report program as an attribute. The logical database then supplies the report program with a set of hierarchically structured table lines which can be taken from different database tables.

Logical databases are special ABAP programs that retrieve data and make it available to application programs. The most common use of logical databases is still to read data from database tables by linking them to executable ABAP programs.

However, from Release 4.5A, it has also been possible to call logical databases using the function module LDB_PROCESS. This allows you to call several logical databases from any ABAP program, nested in any way. It is also possible to call a logical database more than once in a program, if it has been programmed to allow this. This is particularly useful for programs with type 1.

Logical databases contain Open SQL statements that read data from the database. You do not therefore need to use SQL in your own programs. The logical database reads the program, stores them in the program if necessary, and then passes them line by line to the application program or the function module LDB_PROCESS using an interface work area.

Logical Databases - Views of Data

A logical database provides a particular view of database tables in the R/3 System. It is always worth using logical databases if the structure of the data that you want to read corresponds to a view available through a logical database.

The data structure in a logical database is hierarchical. Many tables in the R/3 System are linked to each other using foreign key relationships. Some of these dependencies form tree-like hierarchical structures. Logical databases read data from database tables that are part of these structures.

Advantages of Logical database -

1) No need of programming for retrieval , meaning for data selection

2) Easy to use standard user interface, have check completeness of user input.

Disadvantages

1) Fast in case of lesser no. of tables But if the table is in the lowest level of hierarchy, all upper level tables should be read so performance is slower.

GO THROUGH LINKS -

http://www.sap-basis-abap.com/saptab.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9bfa35c111d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9b5e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_nw04/helpdata/en/c6/8a15381b80436ce10000009b38f8cf/frameset.htm

<u><b>data object</b></u>

A data object is a part of the repository whose content can be addressed and interpreted by the program. All data objects must be declared in the ABAP program and are not persistent, meaning that they only exist while the program is being executed. Before you can process persistent data (such as data from a database table or from a sequential file), you must read it into data objects first. Conversely, if you want to retain the contents of a data object beyond the end of the program, you must save it in a persistent form.

Declaring Data Objects

Apart from the interface parameters of procedures, you declare all of the data objects in an ABAP program or procedure in its declaration part. These declarative statements establish the data type of the object, along with any missing technical attributes. This takes place before the program is actually executed. The technical attributes can then be queried while the program is running.

The interface parameters of procedures are generated as local data objects, but only when the procedure is actually called. You can define the technical attributes of the interface parameters in the procedure itself. If you do not, they adopt the attributes of the parameters from which they receive their values.

Reward points if helpful.

Regards,

Hemant

9 REPLIES 9

former_member588853
Active Contributor
0 Kudos

hi Lakshmanan,

Please search in the Forums first,

you will get the answers..

regards,

nazeer

Former Member
0 Kudos

Hi,

DDIC objects are data dictionary objects, anything that you can create via SE11, including Tables, Data Elements, Domains, Search Helps, Lock Objects, Views, structures, table types, etc.

The ABAP Dictionary centrally describes and manages all the data definitions used in the system. The ABAP Dictionary is completely integrated in the ABAP Development Workbench. All the other components of the Workbench can actively access the definitions stored in the ABAP Dictionary.

The ABAP Dictionary supports the definition of user-defined types (data elements, structures and table types). You can also define the structure of database objects (tables, indexes and views) in the ABAP Dictionary. These objects can then be automatically created in the database with this definition. The ABAP Dictionary also provides tools for editing screen fields, for example for assigning a field an input help (F4 help).

The most important object types in the ABAP Dictionary are tables, views, types (data elements, structures, table types), domains, search helps and lock objects

http://sapabap.iespana.es/sapabap/manuales/learnabap/

http://help.sap.com/saphelp_nw2004s/helpdata/en/43/41341147041806e10000000a1553f6/frameset.htm

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21eb6e446011d189700000e8322d00/content.htm

http://help.sap.com/saphelp_nw2004s/helpdata/en/cf/21ea31446011d189700000e8322d00/frameset.htm

http://help.sap.com/printdocu/core/Print46c/en/data/pdf/BCDWBDIC/BCDWBDIC.pdf

Logical databases are SAP standard programs that are desinged with selections screens that helps easy retrival and access of data from various tables in and efficient manner.

You can get to know more about the logical databases from the SAP documentation or the following links.

A logical database is a special ABAP/4 program which combines the contents of certain database tables. You can link a logical database to an ABAP/4 report program as an attribute. The logical database then supplies the report program with a set of hierarchically structured table lines which can be taken from different database tables.

Advantages of Logical database -

1) No need of programming for retrieval , meaning for data selection

2) Easy to use standard user interface, have check completeness of user input.

Disadvantages

1) Fast in case of lesser no. of tables But if the table is in the lowest level of hierarchy, all upper level tables should be read so performance is slower.

GO THROUGH LINKS -

http://www.sap-basis-abap.com/saptab.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9bfa35c111d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9b5e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_nw04/helpdata/en/c6/8a15381b80436ce10000009b38f8cf/frameset.htm

Regards,

Priyanka.

Former Member
0 Kudos

Hi,

pls go through

logical database;

A logical database is a special ABAP/4 program which combines the contents of certain database tables. You can link a logical database to an ABAP/4 report program as an attribute. The logical database then supplies the report program with a set of hierarchically structured table lines which can be taken from different database tables.

Advantages of Logical database -

1) No need of programming for retrieval , meaning for data selection

2) Easy to use standard user interface, have check completeness of user input.

Disadvantages

1) Fast in case of lesser no. of tables But if the table is in the lowest level of hierarchy, all upper level tables should be read so performance is slower.

GO THROUGH LINKS -

http://www.sap-basis-abap.com/saptab.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9bfa35c111d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9b5e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_nw04/helpdata/en/c6/8a15381b80436ce10000009b38f8cf/frameset.htm

dataobjects:

A data object is a part of the repository whose content can be addressed and interpreted by the program. All data objects must be declared in the ABAP program and are not persistent, meaning that they only exist while the program is being executed. Before you can process persistent data (such as data from a database table or from a sequential file), you must read it into data objects first. Conversely, if you want to retain the contents of a data object beyond the end of the program, you must save it in a persistent form.

Declaring Data Objects

Apart from the interface parameters of procedures, you declare all of the data objects in an ABAP program or procedure in its declaration part. These declarative statements establish the data type of the object, along with any missing technical attributes. This takes place before the program is actually executed. The technical attributes can then be queried while the program is running.

The interface parameters of procedures are generated as local data objects, but only when the procedure is actually called. You can define the technical attributes of the interface parameters in the procedure itself. If you do not, they adopt the attributes of the parameters from which they receive their values.

Reward points if helpful

thanks

Vana

former_member2382
Active Participant
0 Kudos

Are u preparing for the Interview????

Do not put ur question if u not interested in rewarding points... I have seen more post in SDN from you with no REWARDS.

Former Member
0 Kudos

Hi Lakshmanan,

<u><b> Logical databases</b></u> are SAP standard programs that are desinged with selections screens that helps easy retrival and access of data from various tables in and efficient manner.

You can get to know more about the logical databases from the SAP documentation or the following links.

A logical database is a special ABAP/4 program which combines the contents of certain database tables. You can link a logical database to an ABAP/4 report program as an attribute. The logical database then supplies the report program with a set of hierarchically structured table lines which can be taken from different database tables.

Logical databases are special ABAP programs that retrieve data and make it available to application programs. The most common use of logical databases is still to read data from database tables by linking them to executable ABAP programs.

However, from Release 4.5A, it has also been possible to call logical databases using the function module LDB_PROCESS. This allows you to call several logical databases from any ABAP program, nested in any way. It is also possible to call a logical database more than once in a program, if it has been programmed to allow this. This is particularly useful for programs with type 1.

Logical databases contain Open SQL statements that read data from the database. You do not therefore need to use SQL in your own programs. The logical database reads the program, stores them in the program if necessary, and then passes them line by line to the application program or the function module LDB_PROCESS using an interface work area.

Logical Databases - Views of Data

A logical database provides a particular view of database tables in the R/3 System. It is always worth using logical databases if the structure of the data that you want to read corresponds to a view available through a logical database.

The data structure in a logical database is hierarchical. Many tables in the R/3 System are linked to each other using foreign key relationships. Some of these dependencies form tree-like hierarchical structures. Logical databases read data from database tables that are part of these structures.

Advantages of Logical database -

1) No need of programming for retrieval , meaning for data selection

2) Easy to use standard user interface, have check completeness of user input.

Disadvantages

1) Fast in case of lesser no. of tables But if the table is in the lowest level of hierarchy, all upper level tables should be read so performance is slower.

GO THROUGH LINKS -

http://www.sap-basis-abap.com/saptab.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9bfa35c111d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db9b5e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_nw04/helpdata/en/c6/8a15381b80436ce10000009b38f8cf/frameset.htm

<u><b>data object</b></u>

A data object is a part of the repository whose content can be addressed and interpreted by the program. All data objects must be declared in the ABAP program and are not persistent, meaning that they only exist while the program is being executed. Before you can process persistent data (such as data from a database table or from a sequential file), you must read it into data objects first. Conversely, if you want to retain the contents of a data object beyond the end of the program, you must save it in a persistent form.

Declaring Data Objects

Apart from the interface parameters of procedures, you declare all of the data objects in an ABAP program or procedure in its declaration part. These declarative statements establish the data type of the object, along with any missing technical attributes. This takes place before the program is actually executed. The technical attributes can then be queried while the program is running.

The interface parameters of procedures are generated as local data objects, but only when the procedure is actually called. You can define the technical attributes of the interface parameters in the procedure itself. If you do not, they adopt the attributes of the parameters from which they receive their values.

Reward points if helpful.

Regards,

Hemant

Former Member
0 Kudos

hai lakshmanan,

<b>Data Objects</b>

Data objects are the physical units with which ABAP statements work at runtime. The contents of a data object occupy memory space in the program. ABAP statements access these contents by addressing the name of the data object and interpret them according to the data type.. For example, statements can write the contents of data objects in lists or in the database, they can pass them to and receive them from routines, they can change them by assigning new values, and they can compare them in logical expressions.

Each ABAP data object has a set of technical attributes, which are fully defined at all times when an ABAP program is running (field length, number of decimal places, and data type). You declare data objects either statically in the declaration part of an ABAP program (the most important statement for this is DATA), or dynamically at runtime (for example, when you call procedures). As well as fields in the memory area of the program, the program also treats literals like data objects.

<b>Logical Database</b>

A logical database is a special ABAP/4 program which combines the contents of certain database tables. You can link a logical database to an ABAP/4 report program as an attribute. The logical database then supplies the report program with a set of hierarchically structured table lines which can be taken from different database tables.

reward points if helpful.

kavitha

Former Member
0 Kudos

answered

Former Member
0 Kudos

answered