👀 Views: 1 💬 Answers: 1 📅 Created: 2025-06-11

mysql json group_concat sql

I'm relatively new to this, so bear with me. I'm encountering an issue with MySQL 8.0 when trying to use the `JSON` data type in conjunction with the `GROUP_CONCAT` function. I have a table called `orders` that contains a `customer_id` and a `products` column, where `products` is of type `JSON`. The goal is to concatenate the product details for each customer into a single JSON array. Here’s the structure of the `orders` table: ```sql CREATE TABLE orders ( id INT AUTO_INCREMENT PRIMARY KEY, customer_id INT, products JSON ); ``` The data in the `products` column looks something like this: ```json {"product_id": 1, "name": "Widget A"} {"product_id": 2, "name": "Widget B"} ``` I wrote the following query to group the products by `customer_id`: ```sql SELECT customer_id, GROUP_CONCAT(products) AS product_list FROM orders GROUP BY customer_id; ``` However, the result set is returning `NULL` for `product_list` instead of a concatenated string of JSON objects. When I run the query without the `GROUP_CONCAT` function, it correctly returns the JSON data: ```sql SELECT customer_id, products FROM orders; ``` I’ve checked the documentation and it seems that `GROUP_CONCAT` should handle strings, but since `products` is of type `JSON`, I wonder if I need to cast it somehow. I tried casting with `CAST(products AS CHAR)` and `CAST(products AS JSON)` but that did not resolve the issue. Is there a specific way to handle `JSON` types with `GROUP_CONCAT` in MySQL 8.0? Any insights or workarounds would be greatly appreciated! Thanks for your help in advance!