PostgreSQL: Difficulty with JSONB Array Querying in v14.1 Returning Unexpected Results
I'm migrating some code and I'm currently grappling with a JSONB field in PostgreSQL 14.1 that contains an array of objects, and my queries to extract specific values are yielding unexpected results. The JSON structure looks like this: ```json { "items": [ {"id": 1, "name": "Item A"}, {"id": 2, "name": "Item B"}, {"id": 3, "name": "Item C"} ] } ``` I've created a table called `products` with a `data` column of type JSONB. I want to retrieve all products where the `name` is 'Item B'. I wrote the following query: ```sql SELECT * FROM products WHERE data->'items' @> '[{"name": "Item B"}]'; ``` However, this query returns no results, even though I can confirm 'Item B' exists in the JSON. To troubleshoot, I tried using the `jsonb_array_elements` function to iterate through the array: ```sql SELECT * FROM products, jsonb_array_elements(data->'items') AS item WHERE item->>'name' = 'Item B'; ``` This returns the expected record, but I'm concerned about performance because I have a important number of records in the `products` table. I also attempted to create a GIN index on the `data` column like this: ```sql CREATE INDEX idx_products_data ON products USING GIN (data); ``` Even with the index, the original query still doesn't seem to work as intended. The behavior messages I've gotten during my attempts are often quite vague, mainly around the querying method or syntax. Can anyone explain why the `@>` operator fails in this case and suggest a more efficient way to query JSONB arrays without sacrificing performance? This is happening in both development and production on Ubuntu 22.04. What am I doing wrong? I'm coming from a different tech stack and learning Sql. How would you solve this?