postgresql-9.5

问题 I have a table mapping_transform with a JSONB column content_json containing something like { "meta": {...}, "mapping": [ ..., { "src": "up", "dest": "down", ... }, ... ] } I want to add a new JSON entry ( "rule_names": [ "some name" ] ) to the JSON object matching src = up and dest = down , which would result in { "meta": {...}, "mapping": [ ..., { "src": "up", "dest": "down", ..., "rule_names": [ "some name" ] }, ... ] } The following query returns the JSON object that meets the filter

问题 Is there a way to change the PostgreSQL password encryption method from MD5 to SHA? If Yes, can you please tell me how? I am using PostgreSQL 9.5 回答1: Pg 10 With PostgreSQL 10, you can set password_encryption to scram-sha-256 . From the docs When a password is specified in CREATE ROLE or ALTER ROLE without writing either ENCRYPTED or UNENCRYPTED , this parameter determines whether the password is to be encrypted. The default value is md5, which stores the password as an MD5 hash. Setting this

问题 I am trying to test the new PostgreSQL upsert syntax with the following test code, but get the syntax error: test=> CREATE TABLE test1 ( test(> key1 integer PRIMARY KEY check (key1 > 0), test(> key2 integer check (key2 > 0) test(> ); CREATE TABLE test=> CREATE OR REPLACE FUNCTION upsert(IN in_json_array jsonb) test-> RETURNS void AS test-> $func$ test$> UPDATE test1 t SET test$> t.key1 = (obj->>'key1')::int, test$> t.key2 = (obj->>'key2')::int test$> FROM JSONB_ARRAY_ELEMENTS(in_json_array)

问题 i want to calculate the number of row counts in tables present in specific schema.i have calculated the row count of the tables but i want output in format:- Total number of Row Count for table_name is :[value] I have prepared the scripts in which i an getting the count of every table present in the schema. But my concern is i want the output like :- total no. of row count in table_name is [value]. something like this #!/bin/bash databasename="$(cat /home/enterprisedb/.bash_profile |grep

问题 I have table documents , I want to select columns foo and bar. And also the column comments which is jsonb . But in comments I only need the last element that meets condition "isUser":false . "select foo, bar, comments from documents where comments @> '[{"isUser":false}]' limit 1 " /*just limit by 1, the latest comment where isUser = false*/ This is how the json looks liks inside comments column: [{ "text": "1 sample lorem ipsum", "authorId": "0dcd5a36-2778-4fc4-bbc1-112ed61f1362", "timestamp

问题 I have an index: CREATE INDEX index_c_profiles_on_city_state_name_domain ON c_profiles ((data->>'state'), (data->>'city'), name, domain); and another index: CREATE INDEX index_c_profiles_on_state ON c_profiles (state) with a new column I created called 'state' with the value of data->>'state' copied manually over from the jsonb column for each row I tried this query to use the first index: SELECT mm.name, mm.domain, mm.data ->> 'city' as city, mm.data ->> 'state' as state FROM c_profiles as

问题 I have a unique column. I want to insert a row if it's not already there, and then return the id of that row. INSERT INTO t(a) VALUES ('a') ON CONFLICT DO NOTHING RETURNING t.id; returns nothing at all. Here's a fiddle. I'm looking for how to get 1 each time, whether 'a' was newly inserted or not. 回答1: with i as ( INSERT INTO t(a) VALUES ('a') ON CONFLICT (a) DO NOTHING RETURNING id ) select id from i union all select id from t where a = 'a' limit 1 来源： https://stackoverflow.com/questions

问题 I've read the docs and stack, but I'm too dumb to get this without asking my specific question. Say I have an array of objects stored in a jsonb column, e.g. [{"id":1, "value":"a"], {"id":2, "value":"b"}] What is the most efficient way to change index 1's value from "b" to "c" if you don't have the index and must search by id=2? To be more specific, I'm writing a react/redux/node real time app, and I don't want to trust the redux state to give the index to update value. Rather, I want the

问题 I have a table called 'Test' that holds two fields 'qnId' and 'Answers'. 'qnId' stores a uuid and 'Answers' is a jsonb array that roughly looks like this: [{ "user" : "1", "ans" : "some text" }, { "user" : "3", "ans": "some text"}] how can I retrieve the value of "ans" of "user" with value 3 . How can I retrieve the value using normal SQL queries 回答1: demo:db<>fiddle You can use jsonb_array_elements() to expand the array elements into one row each. Afterwards you are able to filter the right

问题 Let's suppose there is a Query called A and it takes 2sec. SELECT ... FROM ... ORDER BY "users_device"."id" # Query A # It contains join clause. # It takes 2sec However, When I run A with declaring CURSOR , it takes 8sec. DECLARE "cursor" NO SCROLL CURSOR WITH HOLD FOR SELECT ... FROM ... ORDER BY "users_device"."id" # It takes 8sec I have tried to compare Query Plan between them and then I found A with CURSOR seems to try to avoid sorting operation. The below is actual query plan. # A