postgresql-9.4 | 易学教程

Merging Concatenating JSON(B) columns in query

阅读更多关于 Merging Concatenating JSON(B) columns in query

问题 Using Postgres 9.4, I am looking for a way to merge two (or more) json or jsonb columns in a query. Consider the following table as an example: id | json1 | json2 ---------------------------------------- 1 | {'a':'b'} | {'c':'d'} 2 | {'a1':'b2'} | {'f':{'g' : 'h'}} Is it possible to have the query return the following: id | json ---------------------------------------- 1 | {'a':'b', 'c':'d'} 2 | {'a1':'b2', 'f':{'g' : 'h'}} Unfortunately, I can't define a function as described here. Is this

Referencing current row in FILTER clause of window function

阅读更多关于 Referencing current row in FILTER clause of window function

问题 In PostgreSQL 9.4 the window functions have the new option of a FILTER to select a sub-set of the window frame for processing. The documentation mentions it, but provides no sample. An online search yields some samples, including from 2ndQuadrant but all that I found were rather trivial examples with constant expressions. What I am looking for is a filter expression that includes the value of the current row. Assume I have a table with a bunch of columns, one of which is of date type: col1 |

jsonb query with nested objects in an array

阅读更多关于 jsonb query with nested objects in an array

问题 I'm using PostgreSQL 9.4 with a table teams containing a jsonb column named json . I am looking for a query where I can get all teams which have the Players 3 , 4 and 7 in their array of players. The table contains two rows with the following json data: First row: { "id": 1, "name": "foobar", "members": { "coach": { "id": 1, "name": "A dude" }, "players": [ { "id": 2, "name": "B dude" }, { "id": 3, "name": "C dude" }, { "id": 4, "name": "D dude" }, { "id": 6, "name": "F dude" }, { "id": 7,

How to perform update operations on columns of type JSONB in Postgres 9.4

阅读更多关于 How to perform update operations on columns of type JSONB in Postgres 9.4

Looking through the documentation for the Postgres 9.4 datatype JSONB, it is not immediately obvious to me how to do updates on JSONB columns. Documentation for JSONB types and functions: http://www.postgresql.org/docs/9.4/static/functions-json.html http://www.postgresql.org/docs/9.4/static/datatype-json.html As an examples, I have this basic table structure: CREATE TABLE test(id serial, data jsonb); Inserting is easy, as in: INSERT INTO test(data) values ('{"name": "my-name", "tags": ["tag1", "tag2"]}'); Now, how would I update the 'data' column? This is invalid syntax: UPDATE test SET data->

Flatten aggregated key/value pairs from a JSONB field?

阅读更多关于 Flatten aggregated key/value pairs from a JSONB field?

I am working in Postgres 9.4 with the following table: Column │ Type │ Modifiers ─────────────────┼──────────────────────┼────────────────────── id │ integer │ not null default practice_id │ character varying(6) │ not null date │ date │ not null pct_id │ character varying(3) │ total_list_size │ double precision │ not null star_pu │ jsonb │ I have the following query: SELECT date, AVG(total_list_size) AS total_list_size, json_object_agg(key, val) AS star_pu FROM (SELECT date, SUM(total_list_size) AS total_list_size, key, SUM(value::numeric) val FROM frontend_practicelist p, jsonb_each_text(star

Flatten aggregated key/value pairs from a JSONB field?

阅读更多关于 Flatten aggregated key/value pairs from a JSONB field?

问题 I am working in Postgres 9.4 with the following table: Column │ Type │ Modifiers ─────────────────┼──────────────────────┼────────────────────── id │ integer │ not null default practice_id │ character varying(6) │ not null date │ date │ not null pct_id │ character varying(3) │ total_list_size │ double precision │ not null star_pu │ jsonb │ I have the following query: SELECT date, AVG(total_list_size) AS total_list_size, json_object_agg(key, val) AS star_pu FROM (SELECT date, SUM(total_list