📋

Description

Error 271, ERR_SQL_DPLC_ALIAS, indicates that an SQL statement or view definition attempts to use the same alias name more than once within the same scope. This typically occurs during database operations, report generation, or custom development when SQL queries are executed against the SAP S/4HANA database.

💬

Error Message

ERR_SQL_DPLC_ALIAS

🔍

Known Causes

4 known causes

⚠️

Duplicate Alias in SELECT Statement

An SQL query within a custom report or application defines the same alias for two different columns or expressions in the SELECT clause.

⚠️

Conflicting Alias in JOIN Clause

When performing JOIN operations, an alias used for one table or subquery conflicts with another alias defined for a different table or subquery within the same query.

⚠️

Ambiguous Alias in Subquery

A nested SQL query (subquery) uses an alias that is already defined in the outer query or another sibling subquery, leading to an ambiguity in scope.

⚠️

View Definition Error

A database view is being created or modified with an underlying SQL statement that contains duplicate aliases, causing the view definition to fail upon execution.

🛠️

Solutions

3 solutions available

1. Identify and Rename Conflicting SQL Alias in ABAP Development medium

Locate the ABAP code causing the duplicate alias and rename it.

1

Analyze the ABAP dump (ST22) to pinpoint the exact source code that is triggering the error. Look for the SELECT statement or CDS view definition that is causing the conflict.

2

Identify the specific table or view that has been assigned the same alias multiple times within the same SQL statement or CDS view context. The error message in ST22 will usually highlight the problematic alias.

3

Modify the ABAP code to use a unique alias for each table or view within the SQL query. If you are using CDS views, ensure that the aliases defined within the view are distinct.

Example of renaming an alias:

Original (problematic):
SELECT a~field1, b~field2 FROM table1 AS a JOIN table2 AS a ON a~key = b~key.

Corrected:
SELECT a~field1, b~field2 FROM table1 AS a JOIN table2 AS b ON a~key = b~key.

4

Reactivate the modified ABAP program or CDS view and test the functionality to confirm the error is resolved.

2. Check and Correct SQL Aliases in SAP HANA Native SQL Procedures or Functions medium

Review HANA native SQL code for duplicate aliases and correct them.

1

Access the SAP HANA Studio or SAP Business Application Studio to review the SQL procedures or functions that are being executed.

2

Examine the SQL statements within these procedures/functions. Pay close attention to JOIN clauses and subqueries where table aliases are defined.

3

Ensure that each table or derived table within a single SQL statement has a unique alias. If an alias is reused, modify it to be distinct.

Example of a problematic SQL statement in a HANA procedure:

SELECT a.column1, b.column2 FROM schema.table1 AS a JOIN schema.table2 AS a ON a.id = b.fk_id;

Corrected SQL statement:

SELECT a.column1, b.column2 FROM schema.table1 AS a JOIN schema.table2 AS b ON a.id = b.fk_id;

4

Save and activate the modified SQL procedure or function. Execute the related application logic to verify the fix.

3. Investigate and Resolve Alias Conflicts in CDS Views medium

Identify and fix duplicate aliases within SAP S/4HANA CDS view definitions.

1

Open the relevant CDS view definition in SAP HANA Studio or SAP Business Application Studio.

2

Review the `FROM` clause and any joins. Look for instances where the same alias is assigned to different tables or subqueries within the same CDS view.

3

Rename the duplicate alias to a unique identifier. This might involve renaming aliases in the main view definition or within associations.

Example of a CDS view with a duplicate alias:

@AbapCatalog.sqlViewName: 'MYCDSVIEW'
define view MY_CDS_VIEW as select from my_table as alias1
  join another_table as alias1 on my_table.key = another_table.key;

Corrected CDS view:

@AbapCatalog.sqlViewName: 'MYCDSVIEW'
define view MY_CDS_VIEW as select from my_table as alias1
  join another_table as alias2 on my_table.key = another_table.key;

4

Save and activate the CDS view. Clear the cache for the CDS view if necessary and re-test the application that uses it.

🔗

Related Errors

5 related errors

SAP S/4HANA Error 271: Duplicate SQL Alias