Error
Error Code:
305
SAP S/4HANA Error 305: Single Row Query Failure
Description
This error indicates that a database query, designed to retrieve exactly one record, has unexpectedly returned multiple records. It typically occurs when a unique identifier or filter condition fails to properly narrow down the result set, violating the single-row expectation of the application or report.
Error Message
ERR_SQL_SINGLE_ROW
Known Causes
3 known causesDuplicate Master Data
Data intended to be unique (e.g., customer ID, material number) contains duplicates in the database, causing a single-row query to retrieve multiple records.
Flawed Query Logic
The underlying SQL query or application code expects a single result but lacks sufficient filtering conditions (e.g., WHERE clause) or uses incorrect joins, allowing multiple rows to be returned.
Missing or Incorrect Parameters
Essential parameters or variables that should narrow down the query's scope to a single record are either not provided or contain invalid values.
Solutions
3 solutions available1. Investigate and Correct SQL Query Logic medium
Analyze the problematic SQL query to ensure it returns exactly one row as expected.
1
Identify the specific ABAP report, transaction code, or custom program that is executing the failing SQL statement. This often requires debugging the application or checking application logs.
2
Extract the exact SQL query that is causing the 'ERR_SQL_SINGLE_ROW' error. This can be done by enabling SQL tracing (e.g., ST05 in SAP GUI) or by examining program code.
SELECT * FROM <table_name> WHERE <condition>; -- Example of a potentially problematic query3
Review the WHERE clause of the SQL query. Ensure that the conditions specified are precise enough to uniquely identify a single row. If multiple rows match, the error will occur.
4
Modify the query to include additional criteria or to use a different approach if multiple rows are legitimately expected but only one is desired. Consider using functions like `ROW_NUMBER()` or `RANK()` if applicable in a more complex scenario (though less common for this specific error).
SELECT * FROM <table_name> WHERE <unique_condition> = '<specific_value>' AND <another_unique_condition> = '<another_specific_value>'; -- Example of a more precise query5
If the intention is to retrieve the *first* matching row, consider using `UP TO 1 ROWS` or similar syntax depending on the specific database dialect (e.g., `FETCH FIRST 1 ROW ONLY` in HANA SQL).
SELECT * FROM <table_name> WHERE <condition> FETCH FIRST 1 ROW ONLY; -- HANA SQL example6
Test the corrected SQL query directly in an SQL client (e.g., SAP HANA Studio, DBVisualizer) to confirm it returns exactly one row. Then, re-run the application or report.
2. Analyze Data Integrity and Table Indexes medium
Ensure data in the relevant table is structured such that unique identifiers consistently yield single rows.
1
Identify the table being queried by the failing SQL statement. This is crucial for data integrity analysis.
2
Examine the primary key and unique indexes defined on the table. If the query relies on these to return a single row, ensure their uniqueness is maintained.
SELECT TABLE_NAME, INDEX_NAME, IS_UNIQUE FROM "SYS"."INDEXES" WHERE TABLE_NAME = '<table_name>'; -- HANA SQL to check index properties3
If the error occurs when querying based on a non-unique field that *should* be unique in the application's context, investigate data inconsistencies. This might involve running custom SQL queries to find duplicate entries.
SELECT <column_name>, COUNT(*) FROM <table_name> GROUP BY <column_name> HAVING COUNT(*) > 1; -- SQL to find duplicate values in a column4
If duplicate data is found and it violates the expected uniqueness, implement a data cleansing process. This might involve writing custom ABAP programs or using ETL tools to correct or remove duplicates.
5
Ensure that the indexes used by the query are present and not corrupted. In rare cases, index corruption could lead to unexpected query results, although this is less likely to manifest as a 'single row' error directly.
3. Review Application Configuration and Customizations advanced
Check for misconfigurations or faulty custom code that might be generating incorrect SQL.
1
Consult SAP Notes and relevant documentation for the specific S/4HANA module or component involved. Error 305 might be a known issue with a specific SAP release or patch level.
2
If the failing query originates from a custom development (e.g., custom ABAP report, CDS view, Fiori app), thoroughly review the source code. Look for any logic that could inadvertently lead to a non-single row result when one is expected.
3
Examine any custom configurations or settings within the S/4HANA system that might influence data retrieval or query behavior for the affected objects.
4
If the error is intermittent, consider whether it's related to specific user actions, data volumes, or background jobs. This can help narrow down the scope of investigation.
5
If the issue persists, consider opening an incident with SAP Support, providing detailed logs, trace files, and the specific steps to reproduce the error.