'Database Index' contains fields from one table.
'Match Code' contain fields from several tables. Match code objects can build on cluster tables, transparent tables, and pooled tables.

The different types of database integrities are specified below -

• Semantic Integrity
• Relational Integrity
• Primary Key Integrity
• Value Set Integrity
• Foreign Key Integrity
• Operational Integrity

ABAP Query (also known as an SAP Query or Query) is a powerful tool used to generate simple reports without any coding.

SQ01 is a transaction code used for SAP Query: Maintain queries in SAP.

Match Code is a tool to help us to search for data records in the system. Match codes are an efficient and user-friendly search tool where key of a record is unknown.
Match code objects builds on cluster tables, transparent tables, and pooled tables.
Database index contains fields only from one table.

SAP memory is a global memory.
ABAP memory is local memory.

Database interface is responsible for the conversion between ABAP/4 data types and the database layer.

SY-TABIX - Current line of an internal table. SY-TABIX is set by the statements below, however only for index tables. The field is either not set or is set to 0 for hashed tables.

• APPEND sets SY-TABIX to the index of the last line of the table, that is, it contains the overall number of entries in the table.
• COLLECT sets SY-TABIX to the index of the existing or inserted line in the table. If the table has the type HASHED TABLE, SY-TABIX is set to 0.
• LOOP AT sets SY-TABIX to the index of the current line at the beginning of each loop loss. At the end of the loop, SY-TABIX is reset to the value that it had before entering the loop. It is set to 0 if the table has the type HASHED TABLE.
• READ TABLE sets SY-TABIX to the index of the table line read. If you use a binary search, and the system does not find a line, SY-TABIX contains the total number of lines, or one more than the total number of lines. SY-INDEX is undefined if a linear search fails to return an entry.
• SEARCH FOR sets SY-TABIX to the index of the table line in which the search string is found.

SY_INDEX - In a DO or WHILE loop, SY-INDEX contains the number of loop passes including the current pass.

GET -
Syntax - GET <nodename>.
GET event occurs(triggers) when the logical database has read a line from the node <nodename> and makes it available to the work area in the program declared using the statement NODES <nodename>.
GET LATE -
Syntax - GET <nodename> LATE
GET LATE event is triggered when all the data records for a node and all the data records of the sub-nodes under it in the hierarchy of the logical database have been read.

The following list specifies some of the system fields(30) -

• SY-DBSYS - Central Database
• SY-HOST - Server
• SY-OPSYS - Operating System
• SY-SAPRL - SAP Release
• SY-SYSID - System Name
• SY-LANGU - User Logon Language
• SY-MANDT - Client
• SY-UNAME - Logon Username
• SY-DATLO - Local Date
• SY-DATUM - Server Date
• SY-TIMLO - Local Time
• SY-UZEIT - Server Time
• SY-DYNNR - Screen Number
• SY-REPID - Current ABAP program
• SY-TCODE - Transaction Code
• SY-ULINE - Horizontal Line
• SY-VLINE - Vertical Line
• SY-INDEX - Number of current loop Pass
• SY-TABIX - Current line of internal table
• SY-DBCNT - Number of table entries processed
• SY-SUBRC - Return Code
• SY-UCOMM - Function Code
• SY-LINCT - Page Length of list
• SY-LINNO - Current Line
• SY-PAGNO - Current Page Number
• SY-LSIND - Index of List
• SY-MSGID - Message Class
• SY-MSGNO - Message Number
• SY-MSGTY - Message Type
• SY-SPONO - Spool number during printing

SM30.

Primary Key – It can accept 0 value and cannot be NULL.
Unique Key – It can be NULL.

There are four types of Joins -

• Self-Join
• Inner Join
• Outer Join
• Equi Join

By using two statements -

• Top-of-page during line-selection
• At line-selection

• Sales Document: Item Data – VBAP
• Sales Document: Partner – VBPA
• Sales Document: Header Data – VBAK
• Sales Document Flow – VBFA
• Sales Document: Delivery Item Data - LIPS
• Customer Master – KNA1
• Material Data – MARA
• Conditions (Transaction Data) – KONV

GET CURSOR statement transfers the name of the screen element on which the cursor is positioned during a user action into the variable <field>.
GET CURSOR FIELD <field> [OFFSET <offset>] [LINE <line>] [VALUE <value>] LENGTH <length>].

Database utility is an interface between the ABAP/4 Dictionary and the underlying the SAP system.

The basic functions of database utility are -

• Create database objects
• Delete database objects
• Adjust database objects to changed ABAP/4 dictionary definition

Transaction SE36.

The main events used for Logical Database are as specified below -

• GET - The programs used for Logical Database are executed with the help of GET event. It mainly takes place when a line from the node was read by the logical database. GET statements determine the depth of the logical database.
• PUT - The program flow is directed by the PUT event.

A logical database is a special ABAP/4 program that combines the contents of certain database tables. Logical database is mostly involved in retrieving data for the concerned application programs. Logical database has the data created by linking more than one table of the database in the special ABAP program. Logical database is specially created during the program running and used to read data from the database tables by linking them.
LDB offers an easy-to-use selection-screens. We can modify the pre-generated selection-screen based on our requirements. It offers reasonable data selections and functions to check whether user input is complete, correct, and plausible. It contains central authorization checks for database accesses. Enhancements such as improved performance immediately apply to all report programs that uses the logical database.

Advantages -

• No need of programming for retrieval, meaning for data selection.
• Easy to use standard user interface, have check completeness of user input.

Disadvantages -

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

If we do not specify a logical database in the program attributes, the GET events never occur.
There is no ENDGET command, so the code block associated with an event ends with the next event statement such as another GET or an END-OF-SELECTION.

Select-options: dname for deptt-dname.

The unique key accepts null values; however, the primary key does not accept null values. Primary key can accept zero value but not null.

There are several database integrities and some of them are - primary key integrity, operational integrity, relational integrity, and semantic integrity.

Yes, we can either create include program in the database or define Macros.

When the internal table ends, a record needs to be added at the certain specified work area. The function of the append statement is to add the record.

No. The data can put into the database only after the data has been entered via transaction.

Indexes are specified as a copy of a database table reduced to specific fields. This data exists in sorted form. This sorting form improve fast access to the field of the tables. In the order that other fields are also read, a pointer to the associated record of the actual table are included in the index. The indexes are activated along with the table and are created automatically with it in the database.

Transparent tables in the dictionary has a one-to-one relation with the table in database. Its structure corresponds to single database field. Table in the database has the same name as in the dictionary. Transparent table holds application data.
Pooled tables in the dictionary has a many-to-one relation with the table in database. Table in the database has the different name as in the dictionary. Pooled table are stored in table pool at the database level.

ABAP/4 Query is a powerful tool to generate simple reports without any coding. ABAP/4 Query can generate the following 3 simple reports -

• Basic List - It is the simple reports.
• Statistics - Reports with statistical functions like Average, Percentages.
• Ranked Lists - For analytical reports.

For creating a ABAP/4 Query, programmer has to create user group and a functional group. Functional group can be created using with or without logical database table. Finally, assign user group to functional group. Finally, create a query on the functional group generated.

Select single fetches first matching record. If more than one matching record are there, then only the first matching record will be considered and other records will not be considered. Whereas, select up to 1 row will fetch all the matching records from the database.

A table physically stores data. A view does not store any data on its own. It can contain data from multiple tables and it just accesses/reads data from those tables.

• Append Structures.
• Customizing Includes.

select 'No, or user, recording routine' while creating TMG.

Cluster table stores the data as name value pair. A cluster table contains data from multiple DDIC tables.

Go to transaction SE11. Press "Copy" button to copy table. Enter the name of the standard table and in the target table enter Z_table name and press enter.

While adjusting database table in SE14, select 'Save Data' radio button.

No, we cannot have same append structure in more than one database table.

After the final selection of the output is performed and the application document is saved, entries are created in the NAST table with application ID, Application document number, output type, output medium, output timing and Status code.

Stores all the forms, driver programs and all NACE settings.

3

Open SQL has 2 system fields with return codes -

• SY-SUBRC
• SY-DBCNT