Active Record 更新所有 JSON 字段

Question

So I have a model Item that has a huge postgresql JSON field called properties . Most of the time this field does not need to be queried on or changed, however we store price in this field.

I'm currently writing a script that updates this price , but there's only a few unique prices and thousands of Items so in order to save time I have a list of Items for each unique price and I'm attempting to do an update all:

Item.where(id: items).update_all("properties->>'price' = #{unique_price}")

But this gives me:

syntax error at or near "->>"

Is there a way to use update all to update a field in a postgres JSON field?

Answer 1

You need to use jsonb_set() function, here is an example :

Item.where(id: items).
     update_all(
       "properties = jsonb_set(properties, '{price}', to_json(#{unique_price}::int)::jsonb)"
     )

This would preserve all values and update only one key.

Read documentation

Answer 2

You can also do this

Item.where(id: items).each do |item|
  properties = item.properties
  item.update(properties: properties.merge({
    price: unique_price
  }))
end

The keyword merge will override the value of the key provided with the new value ie unique_price

Merge documentation is here

Answer 3

What I came up with based on @Philidor's suggestion is very similar but with dynamic bindings:

assignment = ["field = jsonb_set(field, '{ name_of_the_key }', ?)", value.to_json]
scope.update_all(scope.model.sanitize_sql_for_assignment(assignment))