Understanding ABAP CDS Built-in Data Types

One of the first things developers notice when moving from classical ABAP programming to ABAP CDS View Entities is that data types are defined differently.

Although ABAP Classes and CDS View Entities share many common data types, their syntax is different. Understanding these differences is essential because almost every CDS expression—including CAST, CASE, arithmetic operations, currency handling, quantity calculations, and conversion functions—depends on choosing the correct data type.

If you are building RAP applications, CDS View Entities, or APIs in SAP S/4HANA Public Cloud, this is one lesson you should master before moving on to more advanced topics.

One of the most common mistakes beginners make is assuming that CDS uses exactly the same syntax as ABAP Classes.

Although the underlying concepts are similar, CDS View Entities define data types using the abap.* namespace, whereas ABAP Classes use the traditional ABAP type system.

Instead of memorizing every individual data type, it is much easier to group them into logical categories.

We will study each category individually before learning how they are used in CAST expressions and advanced CDS functions.

Built-in data types should be selected based on the nature of the data you are modeling rather than simply choosing the largest available type.

Character data types are the most frequently used built-in types in CDS View Entities. They are used to store identifiers, codes, descriptions, language keys, and other textual business information.

Although they appear simple, each character type serves a different purpose. Choosing the correct type improves readability and prevents unnecessary conversions later in RAP development.

abap.char() is the most commonly used built-in data type in CDS. It stores a fixed number of characters and is typically used for business identifiers whose length never changes.

cast( Supplier as abap.char(10) ) as SupplierText,
cast( Material as abap.char(40) ) as MaterialDescription

DATA lv_company TYPE c LENGTH 4.
DATA lv_name    TYPE c LENGTH 40.

Although NUMC contains only digits, it is still treated as a character-based data type rather than a numeric type.

NUMC is commonly used for business document numbers where leading zeros must be preserved.

cast( PurchaseOrder as abap.numc(10) ) as PurchaseOrder

DATA lv_po TYPE n LENGTH 10.

Example value:

4500001234

abap.string stores variable-length text without requiring a predefined maximum length.

cast( ProductDescription as abap.string ) as Description

DATA lv_text TYPE string.

abap.sstring() represents a short variable-length string and is commonly used in CDS View Entities.

Unlike abap.string, the maximum length must be specified.

cast( ProductText as abap.sstring(255) ) as ProductText

DATA lv_text TYPE string.

Although ABAP does not provide an SSTRING keyword for variable declarations, the type is widely used in the Dictionary and CDS View Entities.

Numeric data types are used whenever mathematical calculations, aggregations, comparisons, or arithmetic expressions are required.

Unlike character types, numeric data types can participate in calculations without requiring explicit conversions.

SAP provides several numeric data types, each designed for different precision and storage requirements.

Integer data types store whole numbers without decimal places. They are commonly used for counters, quantities, loop indexes, flags, and other numeric values that never require fractions.

cast( ItemCount as abap.int4 ) as ItemCount,
cast( SequenceNo as abap.int8 ) as SequenceNumber

DATA lv_counter TYPE int4.
DATA lv_sequence TYPE int8.

abap.dec() represents fixed-point decimal numbers and is one of the most commonly used numeric data types in CDS View Entities.

It is ideal for storing monetary values, percentages, tax amounts, discounts, and business calculations requiring a fixed number of decimal places.

cast( NetAmount as abap.dec(15,2) ) as NetAmount

DATA lv_tax TYPE p LENGTH 8 DECIMALS 2.

abap.decfloat16 stores decimal floating-point numbers with approximately 16 digits of precision.

It provides higher precision than packed decimals and is frequently used for exchange rates and financial calculations.

cast( ExchangeRate as abap.decfloat16 ) as ExchangeRate

DATA lv_rate TYPE decfloat16.

abap.decfloat34 offers approximately 34 digits of precision and is the preferred choice for high-precision business calculations.

cast( Amount as abap.decfloat34 ) as Amount

DATA lv_amount TYPE decfloat34.

abap.fltp represents binary floating-point numbers.

Although it supports decimal values, floating-point arithmetic may introduce rounding differences due to binary representation.

cast( Ratio as abap.fltp ) as Ratio

DATA lv_ratio TYPE f.

Besides character and numeric types, CDS View Entities provide specialized built-in data types for handling currencies, quantities, dates, times, clients, and binary data. These types are widely used in RAP applications and SAP standard VDM views.

abap.curr() represents a currency amount. It should be used together with a corresponding currency key field for proper currency semantics.

cast( NetAmount as abap.curr(15,2) ) as NetAmount

DATA lv_amount TYPE wrbtr.

abap.quan() represents a business quantity. Like CURR, it should always be associated with a Unit of Measure field.

cast( Quantity as abap.quan(13,3) ) as Quantity

DATA lv_qty TYPE menge_d.

Dates and times are represented using dedicated built-in data types. These are frequently used in business documents, audit fields, and RAP applications.

cast( CreationDate as abap.dats ) as CreationDate,
cast( CreationTime as abap.tims ) as CreationTime

SAP provides dedicated built-in types for currencies, units of measure, and client fields.

cast( Currency as abap.cuky ) as Currency,
cast( BaseUnit as abap.unit ) as BaseUnit,
cast( Client as abap.clnt ) as Client

Binary data types are primarily used for UUIDs, hash values, PDF content, images, and other binary objects.

cast( UUID as abap.raw(16) ) as UUID

Follow this lesson in Eclipse ADT as we demonstrate every built-in data type, compare it with the equivalent ABAP Class syntax, and explain where each type is typically used in SAP S/4HANA Public Cloud development.