![]() ![]() JSONB_ARRAY_ELEMENTS(country->'cities') AS cityĪND country -> 'country_name' = 'Norway' JSONB_ARRAY_ELEMENTS(continent->'countries') AS country, JSONB_ARRAY_ELEMENTS(data_column->'continents') AS continent, ![]() (city->'population')::INTEGER AS population You don't need any nesting, you can do lateral queries: SELECT ![]() SELECT jsonb_array_elements(jsonb_array_elements(data -> 'drinkers') -> 'beers') -> 'name'Īnother approach would be to use JSONB contain (i.e. Where n ='x' and v::int between 15 and 25Įfficiently querying JSON with nested arrays in Postgresĭid you try using the IN operator? WHERE 'PBR' IN ( Select *,json_array_elements(p)->'name' n,json_array_elements(p)->'value' v from t Select *,json_array_elements(j->'modes')->'params' p from j sample: t=# create table so40 (i int, j json) I assumed you want to get id of row where exists array element with mentionned values. Querying nested JSON arrays in PostgreSQL Where profile -> 'data' -> 'races' ?| array You need an operator which will match against each element of the JSON. Where profile -> 'data' -> 'races' = ANY(array::jsonb) īut this has the same problem as before, it's checking if the json array equals "white" or "african american". any wants a Postgres array of things to compare, and it has to be an array of jsonb. You probably did that because otherwise you got type errors trying to use any with JSONB. So you're asking if the text matches white or african american. Postgres - JSONB - Nested Columns - Query Nested Jsonb array column School_id | addr_id | house_description | house_no Where addresses->'house_description' = addresses->'house_no' ![]() Jsonb_array_elements(schools->'addresses') addresses Jsonb_array_elements(address_data->'schools') schools, Use jsonb_array_elements() in lateral join as many times as the depth of a json array which elements you want to compare: selectĪddresses->'house_description' house_description, In a following blog post I plan to investigate the performance these json functions.How to query nested arrays in a postgres json column? LEFT JOIN sections ON sections.form_id = form.id LEFT JOIN questions ON ction_id = section.id "name": "c0db64d35a0253561514ee929d813101"Īlternatively you can use Common Table Expressions: WITH questions as ( LEFT JOIN question ON ction_id = form.idįetch the JSON objects of a form using nested sub-queries: SELECT row_to_json(forms) LEFT JOIN section ON section.form_id = form.id With json functions, postgres can do the transformations instead.īasic model: DROP TABLE IF EXISTS question įetch the normalized representation of a form: SELECT Moving the normalized data between the db and the application layer is redundant. For example many ORMs will support something like formRepository.find(), which will do something like this behind the scenes. Often the application layer will transform normalized data from the db into a hierarchical object. Building Nested Json Objects With Postgresīuilding nested json objects with postgres ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |