String Functions in ABAP CDS View Entities

45 min read

Why Every ABAP Cloud Developer Should Master String Functions

Business data is not always stored in the exact format required by users or downstream applications. Customer numbers may require leading zeros, document numbers may need formatting, text values often need trimming, and identifiers frequently need to be extracted or modified before they are displayed in reports or Fiori applications.

Instead of performing these operations in ABAP after retrieving the data, SAP recommends pushing string manipulation to the database whenever possible. ABAP CDS provides several built-in string functions that execute directly in SAP HANA, improving performance while keeping business logic inside the CDS View Entity.

String Functions in ABAP CDS View Entities
String Functions allow SAP HANA to format, manipulate and transform text directly inside CDS View Entities, reducing ABAP post-processing.
Click image to enlarge

Learning Objectives

After Completing This Lesson You Will Be Able To

SkillDescription
Format Business DataPad, trim and format character fields.
Manipulate StringsExtract, replace and search text.
Improve PerformancePush string processing to SAP HANA.
Avoid Common MistakesUnderstand the behavior and limitations of string functions.
Build Better CDS ViewsProduce business-ready output directly from CDS.

String Functions Overview

SAP provides several built-in string functions that can be grouped into four major categories.

Categories of String Functions

CategoryFunctions
PaddingLPAD(), RPAD()
TrimmingLTRIM(), RTRIM()
Searching & ExtractionINSTR(), SUBSTRING(), LEFT(), RIGHT(), LENGTH()
ModificationREPLACE(), LOWER(), UPPER(), CONCAT()

Architect Perspective

Architect Insight

Most production CDS Views use only a small subset of these functions. LPAD(), SUBSTRING(), REPLACE(), LENGTH(), and CONCAT() are among the most frequently used functions in RAP applications and analytical reporting.

LPAD()

Adds characters to the left side of a string until the specified length is reached.

ABAP CDS Syntax

lpad( source, total_length, pad_character )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
lpad(
    SoldToParty,
    12,
    '0'
) as Customer

Example Result

InputOutput
12345000000012345
SAP000000000SAP

Real Project Example: Customer Number Formatting

Business Partner, Customer, Vendor, Material and Document numbers are often expected to have a fixed length. LPAD() is commonly used to prepend leading zeros before exposing values to external systems or reports.

💡 SAP Best Practice

Use LPAD() only for presentation purposes. Do not use padded values for joins or business logic because they may no longer match the original database value.

RPAD()

Adds characters to the right side of a string until the required length is reached.

ABAP CDS Syntax

rpad( source, total_length, pad_character )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
rpad(
    SalesOrganization,
    8,
    '_'
) as SalesOrg

Example Result

InputOutput
17101710____
SAPSAP****

Real Project Example: Fixed-Length Export Files

Legacy systems often require fixed-width records. RPAD() allows shorter values to be extended to the required length while preserving the original content.

LTRIM()

Removes the specified character from the left side of a string until a different character is encountered.

ABAP CDS Syntax

ltrim( source, character )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
ltrim(
    SalesDocument,
    '0'
) as SalesDocument

Example Result

InputOutput
0000123456123456
00000010001000
000120030120030

Architect Perspective

Important

LTRIM() removes matching characters only from the beginning of the string.

Characters appearing later in the string remain unchanged.

RTRIM()

Removes the specified character from the right side of a string.

ABAP CDS Syntax

rtrim( source, character )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
rtrim(
    'SAP****',
    '*'
)

Example Result

InputOutput
SAP****SAP
ABC___ABC

Real Project Example: Cleaning Imported Data

Imported files sometimes contain trailing filler characters or padding. RTRIM() removes these characters before exposing the data to applications or reports.

SUBSTRING()

Extracts a portion of a string beginning at a specified position.

ABAP CDS Syntax

substring( source, start_position, length )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
substring(
    SalesDocument,
    1,
    6
) as SalesDocPrefix

Example Result

InputStartLengthOutput
900012345616900012
ABCDEFGHIJ43DEF

Real Project Example: Document Number Prefix

Many organizations encode business information within document numbers. SUBSTRING() allows a CDS View to extract prefixes, suffixes, company identifiers, or fiscal information directly in SAP HANA.

LEFT()

Returns the specified number of characters from the beginning of a string.

ABAP CDS Syntax

left( source, length )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
left(
    SalesDocument,
    4
) as Prefix

Example Result

InputOutput
90001234569000
ABCDEFGHIJABCD

Real Project Example: Company Prefix

LEFT() is commonly used when document numbers or business partner IDs contain meaningful prefixes that need to be reported independently.

RIGHT()

Returns the specified number of characters from the end of a string.

ABAP CDS Syntax

right( source, length )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
right(
    SalesDocument,
    4
) as Suffix

Example Result

InputOutput
90001234563456
ABCDEFGHIJGHIJ

Real Project Example: Fiscal Year or Sequence Number

RIGHT() is frequently used when the last few characters represent sequence numbers, fiscal years, or regional identifiers embedded within business keys.

INSTR()

Returns the position of the first occurrence of a substring.

ABAP CDS Syntax

instr( source, search_string )

Returns

Integer

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
instr(
    SalesDocument,
    '1'
) as Position

Example Result

InputSearchResult
9000123456'1'5
ABCDABC'C'3
ABCDEFG'X'0

Architect Perspective

Important

Character positions begin at 1, not zero.

If the search text is not found, INSTR() returns 0.

Real Project Example: Reference Number Validation

A CDS View can quickly determine whether a separator, prefix, or identifier exists inside a reference number before exposing it to reporting applications.

LENGTH()

Returns the number of characters contained in a string.

ABAP CDS Syntax

length( source )

Returns

Integer

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
length(
    CustomerName
) as NameLength

Example Result

InputOutput
SAP3
CloudABAP10
Sales Order11

Real Project Example: Data Quality Checks

LENGTH() is commonly used in validation CDS Views to identify values that do not meet the expected business format, such as customer IDs, material numbers, or external reference numbers.

REPLACE()

Replaces every occurrence of one string with another.

ABAP CDS Syntax

replace( source, search_string, replace_string )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
replace(
    SalesDocument,
    '0',
    'X'
) as FormattedDocument

Example Result

InputOutput
90001234569XXX123456
SAP CloudSAP RAP

Real Project Example: Data Transformation

REPLACE() is useful when transforming imported values, standardizing separators, masking sensitive data, or preparing text for downstream applications.

💡 SAP Best Practice

REPLACE() substitutes every matching occurrence. If only the first occurrence should change, additional logic is required because REPLACE() does not stop after the first match.

LOWER()

Converts all alphabetic characters to lowercase.

ABAP CDS Syntax

lower( source )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
lower(
    CustomerName
) as CustomerName

Example Result

InputOutput
SAPsap
CloudABAPcloudabap

Real Project Example: Search Optimization

LOWER() helps normalize text before comparisons or search operations, ensuring consistent behavior regardless of the original letter casing.

UPPER()

Converts all alphabetic characters to uppercase.

ABAP CDS Syntax

upper( source )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
upper(
    CustomerName
) as CustomerName

Example Result

InputOutput
sapSAP
CloudAbapCLOUDABAP

Real Project Example: Standardized Reporting

Reports often require values to be displayed in a consistent uppercase format regardless of how they were originally entered into the system.

Architect Perspective

Architect Insight

Although all of these functions manipulate strings, they serve very different purposes.

Use SUBSTRING(), LEFT(), andRIGHT() for extraction, INSTR() for searching, LENGTH() for validation, REPLACE() for transformation, and LOWER()/UPPER() for normalization.

Choosing the right function keeps your CDS View easier to understand and avoids unnecessary complexity.

CONCAT()

Concatenates two character strings into a single string.

ABAP CDS Syntax

concat( source1, source2 )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
concat(
    SalesOrganization,
    DistributionChannel
) as SalesArea

Example Result

InputOutput
1710 + 10171010
SAP + CloudSAPCloud

Real Project Example: Building Composite Business Keys

CONCAT() is frequently used to combine multiple business fields into a single identifier for reporting or integration scenarios.

💡 SAP Best Practice

CONCAT() joins only two expressions. For longer strings, CONCAT_WITH_SPACE() or nested CONCAT() expressions provide better readability.

CONCAT_WITH_SPACE()

Concatenates two strings while inserting the specified number of spaces between them.

ABAP CDS Syntax

concat_with_space( source1, source2, spaces )

Returns

Character String

Code Pushdown

✅ Supported

Supported Types

CHARSSTRINGSTRING
Example
ABAP CDS
concat_with_space(
    FirstName,
    LastName,
    1
) as FullName

Example Result

InputOutput
John + SmithJohn Smith
SAP + CloudSAP Cloud

Real Project Example: Employee and Business Partner Names

Instead of nesting multiple CONCAT() functions, CONCAT_WITH_SPACE() creates readable display names for employees, customers, suppliers, and business partners with minimal code.

Architect Perspective

Architect Insight

Whenever you simply need to insert spaces between two values, CONCAT_WITH_SPACE() is much easier to read and maintain than nested CONCAT() expressions.

Common Mistakes

❌ Common Mistakes

  • Using LPAD() or RPAD() for business logic instead of presentation formatting.
  • Assuming SUBSTRING() starts at position 0 instead of 1.
  • Expecting INSTR() to return -1 when text is not found. It returns 0.
  • Using REPLACE() when only the first occurrence should be modified.
  • Writing nested CONCAT() expressions where CONCAT_WITH_SPACE() is clearer.
  • Performing string manipulation in ABAP that could be pushed down to SAP HANA.

Performance Considerations

String functions execute directly in SAP HANA as part of the generated SQL statement. This allows formatting and transformation to benefit from code pushdown while reducing application server processing.

Performance Recommendations

RecommendationReason
Perform formatting in CDS whenever possible.Supports code pushdown.
Avoid unnecessary nested functions.Improves readability and maintainability.
Use CONCAT_WITH_SPACE() instead of nested CONCAT().Cleaner and easier to maintain.
Keep presentation formatting separate from business logic.Makes CDS Views easier to understand.

Interview Questions

BeginnerInterview Question

What is the difference between LPAD() and RPAD()?

Answer: LPAD() adds characters to the left of a string, while RPAD() adds characters to the right until the specified length is reached.

BeginnerInterview Question

What does SUBSTRING() return?

Answer: It extracts a portion of a string beginning at the specified position for the requested length.

ExperiencedInterview Question

What value does INSTR() return if the search string is not found?

Answer: INSTR() returns 0.

ExperiencedInterview Question

Does SUBSTRING() use zero-based indexing?

Answer: No. Character positions begin at 1.

ExperiencedInterview Question

When should CONCAT_WITH_SPACE() be preferred over CONCAT()?

Answer: Whenever two values simply need to be joined with spaces, such as building employee names or business partner display texts.

ExperiencedInterview Question

Does REPLACE() modify only the first occurrence?

Answer: No. REPLACE() substitutes every matching occurrence within the source string.

ArchitectInterview Question

Why are string functions recommended inside CDS View Entities?

Answer: Because they execute directly in SAP HANA, reducing ABAP post-processing and supporting code pushdown.

ArchitectInterview Question

Which string functions are most commonly used in production RAP projects?

Answer: LPAD(), SUBSTRING(), LENGTH(), REPLACE(), CONCAT(), CONCAT_WITH_SPACE(), LOWER(), and UPPER().

📝
Developer Reference

String Functions Cheat Sheet

This quick reference summarizes the most commonly used string functions in ABAP CDS. Keep it handy while building CDS View Entities, RAP applications, or preparing for technical interviews.

FunctionPurpose
LPAD()Pad characters on the left
RPAD()Pad characters on the right
LTRIM()Remove leading characters
RTRIM()Remove trailing characters
SUBSTRING()Extract part of a string
LEFT()Return leftmost characters
RIGHT()Return rightmost characters
INSTR()Find first occurrence
LENGTH()Return string length
REPLACE()Replace all matching text
LOWER()Convert to lowercase
UPPER()Convert to uppercase
CONCAT()Join two strings
CONCAT_WITH_SPACE()Join two strings with spaces

💡 Key Takeaway

String functions enable CDS View Entities to format, transform, and manipulate character data directly in SAP HANA. This reduces ABAP post-processing while producing business-ready output for RAP applications, analytical reports, and APIs.

Understanding when to use functions such as LPAD(), SUBSTRING(), REPLACE(), LENGTH(), CONCAT(), and CONCAT_WITH_SPACE() allows you to build cleaner, more maintainable, and production-ready CDS Views.

Whenever string manipulation can be performed in CDS, prefer database execution over application-layer processing to fully leverage code pushdown in SAP HANA.

Watch the Complete ADT Walkthrough

In the accompanying video, we'll implement every string function covered in this lesson using Eclipse ADT and SAP S/4HANA Public Cloud. We'll build practical examples, discuss common mistakes, and demonstrate production-ready scenarios used in RAP applications.