Rails nested jsonb query

Question

i have active record object like this

`<BlockExercise id: 1, type: nil, user_id: 1, number: "S51_1", status: "close", exercise_distribution: {"Day1"=>{"BN3"=>"", "SQ1"=>"", "date"=>"10/03/2019"}, "Day2"=>{"BN2"=>"", "date"=>""}, "Day3"=>{"DL1"=>"", "date"=>""}, "Day4"=>{"DL2"=>"", "SQ2"=>"", "date"=>""}, "Day5"=>{"BN1"=>"", "date"=>""}}, created_at: "2019-03-15 18:59:02", updated_at: "2019-03-15 18:59:02"> `

Here column exercise_distribution is jsonb type. As this is a single object(row) and here is multiple keys(days) with uniq values. i want key(day) which has date present or not null. so here anser will be "Day1"=>{"BN3"=>"", "SQ1"=>"", "date"=>"10/03/2019"} how do i get this by sql query or any other suitable way.

Answer 1

This whole question is indicating that you are using JSONB where you should actually use the relational model and actually create a table which is an anti-pattern .

json is the new EAV – a great tool when you need it, but not something you should use as a first choice.

While you can query based on a JSONB column:

BlockExercise.where("(Day1->>'date' <> '') IS NOT TRUE")

The way your data structure is layed out its going to be really clunky since you have to do:

BlockExercise.where("(Day1->>'date' <> '') IS NOT TRUE")
             .where("(Day2->>'date' <> '') IS NOT TRUE")
             # ...

Joining records on the other hand is much simpler and more effective.

BlockExercise.joins(:exercise_distributions)
             .where.not(date: nil)