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Description

This error indicates that an SQL query or database operation could not uniquely identify a table due to ambiguous referencing. It commonly occurs in queries involving multiple tables where table or column names are not sufficiently qualified.

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Error Message

ERR_SQL_AMBG_TABLE: Table ambiguously defined

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Known Causes

3 known causes

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Missing Table Aliases

When joining multiple tables, columns with identical names are referenced without using distinct table aliases, making their origin unclear to the database.

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Unqualified Column References

A column is referenced in a query without explicitly specifying its parent table, and that column name exists in more than one table involved.

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Duplicate Table Instances

The same table is included multiple times in a query (e.g., for a self-join) without assigning unique aliases to differentiate each instance.

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Solutions

3 solutions available

1. Identify and Qualify Ambiguous Table References in Custom Code medium

Locate and explicitly qualify table names in custom ABAP programs or HANA SQL scripts that are causing ambiguity.

1

Analyze the error message to identify the specific SQL statement and the tables involved. The error message often provides clues about the context of the ambiguity.

ERR_SQL_AMBG_TABLE: Table ambiguously defined. Statement: SELECT * FROM my_table t1 JOIN another_table t2 ON t1.field = t2.field WHERE t1.id = '123'

2

Examine the ABAP code or HANA SQL script where the error occurs. Look for instances where the same table name is referenced multiple times, either directly or through aliases, without proper qualification.

ABAP Example (problematic):
DATA: lt_data TYPE STANDARD TABLE OF my_table.
SELECT * FROM my_table INTO TABLE lt_data.

HANA SQL Example (problematic):
SELECT * FROM my_table t1, my_table t2 WHERE t1.id = t2.id;

3

Qualify table references by using explicit table names or aliases, especially when joins or subqueries are involved. Ensure each table in a join is uniquely identified.

ABAP Example (corrected):
DATA: lt_data TYPE STANDARD TABLE OF my_table.
SELECT * FROM my_table AS mt INTO TABLE lt_data.

HANA SQL Example (corrected):
SELECT t1.* FROM my_table AS t1 JOIN my_table AS t2 ON t1.id = t2.id WHERE t1.id = '123';

4

If the ambiguity arises from a view or a complex query, ensure that all underlying tables within the view are properly aliased or qualified if they are also referenced directly in the main query.

HANA SQL Example (view):
CREATE VIEW my_ambiguous_view AS
SELECT
  t1.col1,
  t2.col2
FROM
  table_a t1
JOIN
  table_b t2 ON t1.id = t2.id;

-- Query causing ambiguity if table_a is also referenced directly:
SELECT
  mv.col1,
  ta.other_col
FROM
  my_ambiguous_view mv
JOIN
  table_a ta ON mv.col1 = ta.id;

5

Test the modified code thoroughly to ensure the ambiguity is resolved and the query executes as expected.

N/A

2. Review and Correct Ambiguous Table Names in Standard SAP Objects advanced

Investigate if the error originates from a custom modification or enhancement to a standard SAP object that has introduced table name conflicts.

1

Utilize SAP's tools like 'Where-Used List' (SE38/SE11) for the problematic table name or related objects to identify all instances where it's being used.

Transaction: SE38 or SE11
Object: Enter the table name or related program/structure name.
Action: Select 'Where-Used List'.

2

Focus on custom developments, user exits, BADIs, enhancement spots, or custom tables that might share naming conventions with standard SAP tables.

N/A

3

If you find custom code that is using a table name that is too similar to a standard SAP table (e.g., Z_MARA vs. MARA), rename the custom table or the conflicting reference in the custom code to ensure uniqueness.

Example: If a custom table is named 'Z_EKKO' and the standard table is 'EKKO', rename 'Z_EKKO' to something like 'Z_CUSTOM_EKKO' or adjust the query referencing it.

4

If the ambiguity is within a standard SAP object (which is rare but possible with complex upgrades or patches), it's crucial to raise an incident with SAP Support. Provide detailed information about the error and the context.

Transaction: SAP Solution Manager (SolMan) or SAP ONE Support Launchpad
Component: BC-ABA-LA or BC-DB-HDB
Details: Include error message, transaction code, program name, and steps to reproduce.

5

Apply any SAP Notes or patches that might be available for the reported issue, especially if it's identified as a bug in standard SAP code.

Transaction: SNOTE
Action: Check for relevant SAP Notes.

3. Examine HANA Calculation Views and SQL Script Logic medium

Debug HANA Calculation Views or native SQL scripts that might have duplicate table or view references.

1

Open the problematic Calculation View or SQL script in the SAP HANA Studio or SAP Business Application Studio.

Tool: SAP HANA Studio or SAP Business Application Studio
Action: Navigate to the Calculation View or SQL Script file.

2

Review the graphical model of the Calculation View. Look for any data sources or projections that are mapped to the same physical table or view, especially if they are being joined or unioned.

N/A

3

In the SQL Script, identify all table and view references. Use aliases consistently for all tables and views, even if they are only referenced once, to prevent future ambiguity and improve readability.

HANA SQL Example:
SELECT
  t1.column_a,
  t2.column_b
FROM
  schema_name.table_one AS t1
JOIN
  schema_name.table_two AS t2 ON t1.id = t2.id
WHERE
  t1.status = 'ACTIVE';

4

If a view is used, ensure that the view definition itself does not cause table ambiguity within its own logic, and that its usage in the outer query is also unambiguous.

N/A

5

Execute the modified view or script in a test environment and verify that the error is resolved.

N/A

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Related Errors

5 related errors

SAP S/4HANA Error 387: SQL Table Ambiguity