What is foreign key in SAP ABAP with example?
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What is foreign key in SAP ABAP with example?
A foreign key allows you to assign data records in the foreign key table and check table. By using the entries in the foreign key fields, one record of the foreign key table uniquely identifies one record of the check table.
What are foreign keys in SAP ABAP?
You use foreign keys to define relationships between tables in the ABAP Dictionary, create value checks for input fields and link several tables in a view or a lock object . A foreign key links two tables T1 and T2 by assigning fields of table T1 to the primary key fields of table T2.
How do I find a foreign key in SAP ABAP?
Normally, if you are trying to locate a foreign key, you can proceed as follows.
- Transaction Code: SE11.
- Enter the table in question. For example BSEG.
- Select a table field. For example BUKRS or KUNNR.
- Click on Foreign Keys.
- A screen will pop-up with the foreign key fields and tables where you can see the CHECK TABLE.
How many types of foreign keys are there in SAP ABAP?
Now at the below screen, you can see the option of Foreign key field type, which is containing four options. We have already explained these options in the above section. Now click on the Generate proposal button, and then click to the copy button.
What is the difference between primary key and foreign key in SAP ABAP?
A primary key is a field or combination of fields that uniquely identify a record in a table, so that an individual record can be located without confusion. A foreign key (sometimes called a referencing key) is a key used to link two tables together.
What is generic key in SAP ABAP?
The generic key is a part of the primary key of the table that is left-justified. Tip. In this example, a program reads the record highlighted in red from table SCOUNTER. If the table is generically buffered, all records whose generic key values (MANDT and CARRID) agree are loaded into the buffer.
What is generic buffer in ABAP?
You use generic buffering to load in the buffer all the records whose generic key fields match with the accessed record of the table. The generic key is a part of the primary key of the table that is left-justified. In this example, a program reads the record highlighted in red from table SCOUNTER.
Can a foreign key have duplicate values?
A foreign key can contain duplicate values. There is no limitation in inserting the values into the table column. While inserting any value in the foreign key table, ensure that the value is present into a column of a primary key.
What is the use of ST02 Tcode in SAP?
Tune summary (transaction ST02) displays buffer and memory resources in the ABAP system.
What is buffering and types of buffering in SAP ABAP?
The buffering type defines which table records are loaded into the buffer of the application server when a table record is accessed. There are the following buffering types: Full buffering: All the records of the table are loaded into the buffer when one record of the table is accessed.
Can we store null value in foreign key?
Yes,You can null value in Foreign key Column.
What if foreign key is null?
A foreign key containing null values cannot match the values of a parent key, since a parent key by definition can have no null values. However, a null foreign key value is always valid, regardless of the value of any of its non-null parts.
What is the role of a foreign key?
A foreign key (FK) is a column or combination of columns that is used to establish and enforce a link between the data in two tables to control the data that can be stored in the foreign key table.
What is AL08 used for in SAP?
Transaction code AL08 shows the list of all the users who are logged on to the system globally or for all the instances in the system which are active. • Active instance – Shows the Active instance.
What are swaps in ST02?
Buffer swaps occurs when there are no sufficient directories or space. When more swaps occur they are displayed on ST02 in swaps column. Analysis: Identify the buffer areas whose swaps/ Database access are more. Buffer Swaps indicate the following.
