Object list: Error "Subquery returns more than 1 row"

Problem

When opening an object list or setting a filter, an error message ending with "Subquery returns more than 1 row" is displayed instead of the expected objects. Often only specific object types are affected (e.g. servers, switches).

Cause

The database contains single-value categories (categories that allow only one entry per object) with more than one record. This can be caused by:

• Faulty imports (CSV, JDisc)
• API calls that write duplicate entries
• List editing on many objects simultaneously
• Database migration issues during updates

The SQL query for the object list expects exactly one value for single-value categories — if the database returns multiple, the error occurs.

Solution

Step 1: Run system repair

1. Navigate to Administration > System Tools > Cache / Database
2. Run the System Repair — this automatically detects and fixes duplicate single-value entries

In many cases, this is sufficient to resolve the problem.

Step 2: Location correction (if location column is affected)

If the error occurs when displaying the location column in the object list:

1. Navigate to Administration > System Tools > Cache / Database
2. Run the Location Correction

Step 3: Manual cleanup via SQL

If the system repair does not resolve the issue, duplicate entries can be identified manually. In this case, contact support at help@i-doit.com with:

• The exact error message
• The affected object type
• The i-doit version

Detailed documentation: System repair in the Knowledge Base