midMySQL
Aggregating with GROUP_CONCAT
Updated May 4, 2026
Short answer
Concatenates multiple row strings into a single string.
Deep explanation
Invaluable for rolling up one-to-many relationships into a single summary row.
Real-world example
Displaying all tags associated with a blog post in one field.
Common mistakes
- Hitting the 'group_concat_max_len' limit, which truncates data.
Follow-up questions
- Can you change the separator?