Problem

When creating a new service group via the admin UI, a 500 error occurs with:

Duplicate entry '2' for key 'service_groups.PRIMARY'

Root Cause

The ServiceGroup entity uses GenerationType.AUTO for ID generation:

// app/src/main/java/app/model/service/group/ServiceGroup.java:26-28
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

This is inconsistent with all other entities which use GenerationType.IDENTITY:

With MySQL, GenerationType.AUTO uses a hibernate_sequence table to track the next ID value. This sequence can get out of sync when data is seeded or imported with explicit IDs.

Recommended Fix

Change ServiceGroup to use GenerationType.IDENTITY to match other entities:

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

This uses MySQL's native AUTO_INCREMENT which is more reliable and consistent with the rest of the codebase.

Workaround

Until fixed, update the hibernate_sequence table (which GenerationType.AUTO actually uses):

-- Check current sequence value
SELECT * FROM hibernate_sequence;

-- Update to a safe value higher than any existing ID
UPDATE hibernate_sequence SET next_val = 10;

-- Optionally also reset MySQL auto-increment (belt and suspenders)
SELECT MAX(id) FROM service_groups;
ALTER TABLE service_groups AUTO_INCREMENT = <max_id + 1>;

Impact

• Severity: Medium - Admin functionality blocked
• Affected: Creating new service groups