Join VS For all Entries

DPM125 — Tue, 05 Aug 2025 19:11:51 +0000

Joins

combine rows from two or more tables based on a related column, usually a key field. ABAP supports various join types (INNER JOIN, LEFT OUTER JOIN, etc.) mostly used inside Open SQL queries.

How to Use Joins:

SELECT a~vbeln, a~erdat, b~posnr, b~matnr
FROM vbak AS a
INNER JOIN vbap AS b ON a~vbeln = b~vbeln
INTO TABLE @DATA(result).

Here, sales order header (vbak) is joined with sales order items (vbap) on the sales order number (vbeln).
Result is fetched in one go, improving performance by reducing database calls.

FOR ALL ENTRIES

is a clause in ABAP that allows you to select records from a table where a field matches any entry in an internal table, acting like an “IN” condition.

How to Use FOR ALL ENTRIES:

DATA: lt_vbak TYPE TABLE OF vbak,
lt_vbap TYPE TABLE OF vbap.

” First select sales orders into internal table
SELECT vbeln erdat vkorg kunnr FROM vbak
INTO TABLE lt_vbak
WHERE vkorg = ‘1000’.

” Use FOR ALL ENTRIES to select matching items
IF lt_vbak IS NOT INITIAL.
SELECT vbeln posnr matnr FROM vbap
    INTO TABLE lt_vbap
    FOR ALL ENTRIES IN lt_vbak
    WHERE vbeln = lt_vbak-vbeln.
ENDIF.

The first SELECT fetches sales orders for a sales org.
The second SELECT fetches all items related to these orders.
This reduces database hits compared to looping with multiple selects.

What is the difference between association vs Joins in CDS ?

DPM125 — Tue, 05 Aug 2025 18:30:22 +0000

Association An association is a declarative relationship between CDS entities (like foreign keys), defined using the association keyword. Key Characteristics: Lazy/Evaluated-on-demand: Data from the association is not fetched unless it is explicitly accessed using a path expression (like to_customer.name). Navigation-style access: You can access associated data using dot (.) notation. Defined once, reused many times: Associations can be defined once and used in multiple views or queries. Cardinality can be defined: e.g. [0..1], [1..*].

define view ZSalesOrder as select from sales_order
association [0..1] to customer as _Customer on $projection.customer_id = _Customer.id
{
key sales_order_id,
customer_id,
_Customer.name
}

Here, _Customer is an association. It won’t trigger a join unless _Customer.name is accessed.

Join

A join is an explicit operation in CDS to combine two data sources based on a condition, much like in SQL. Key Characteristics: Eager execution: The join happens immediately during view evaluation. More control: You control the type of join (INNER, LEFT OUTER, etc.). Typically used when data from both tables is always needed.

define view ZSalesOrderJoin as select from sales_order
inner join customer on sales_order.customer_id = customer.id
{
sales_order.id,
customer.name
}

Here, a real-time INNER JOIN is performed.

When to Use What?

Use Association:

When modeling data relationships.
When you want flexibility and better performance for optional fields.
When the associated data isn’t always needed.

Use Join:

When you always need data from both sources.
When performing aggregations or filters based on joined fields.
When doing complex multi-joins with specific types (e.g. inner join).

joins – SAP EWM Help

Join VS For all Entries

How to Use Joins:

How to Use FOR ALL ENTRIES:

What is the difference between association vs Joins in CDS ?

When to Use What?