postgresql

问题 I have defined the following index: CREATE INDEX users_search_idx ON auth_user USING gin( username gin_trgm_ops, first_name gin_trgm_ops, last_name gin_trgm_ops ); I am performing the following query: PREPARE user_search (TEXT, INT) AS SELECT username, email, first_name, last_name, ( -- would probably do per-field weightings here s_username + s_first_name + s_last_name ) rank FROM auth_user, similarity(username, $1) s_username, similarity(first_name, $1) s_first_name, similarity(last_name, $1

问题 I have a model with a has_many relation with another model like so: class Parent < ActiveRecord::Base has_many :children end class Child < ActiveRecord::Base belongs_to :parent end Since there are some parents that may not have children, I'd like to do a query that returns only the parents that DO have children. How would I go about something like this? Since I'm doing this on Rails 3, it would be helpful if this query were to not use the where.not. syntax. 回答1: Rails 4 Parent.includes(:child

问题 I'm trying to add a nested serializer to an existing serializer based on some criteria of the parent model, not a Foreign key. The use case is to return a 'Research' object with an array of 'ResearchTemplate' objects that are identified by filtering on a Postgres ArrayField. Models class Research(TimeStampedModel): category = models.CharField(max_length=100, choices=RESEARCH_TEMPLATE_CATEGORIES, default='quote') body = models.CharField(max_length=1000, blank=True, default='') #The body of

问题 I have the following function that writes into a PostgreSQL database. I need to make it safe from SQL injection however I am not sure how to do that. The part of the query assembled from pg_query_params is safe from injection (or so I have been told) however the other part of the assembled query via PHP's string concatenation . is apparently vulnerable to injection. private function setItem($table, $id, $field, $itemId, $fieldValue){ $_1 = $itemId; $_2 = $fieldValue; $_3 = $field; $_4 =

问题 ASP.NET MVC Core 5 application uses Npgsql to get data from Postgres database. Columns in database are defined as CHAR(n) type, like: create table prpalk ( sfirmanimi char(100) ); Column types cannot be changed to varchar. Postgres database encoding is unicode. However some columns are in custom encoding which needs to be converted to unicode to be used in .NET. Those column names in database start always with word Custom. I tried Dapper to get data but data contains trailing spaces and

问题 ASP.NET MVC Core 5 application uses Npgsql to get data from Postgres database. Columns in database are defined as CHAR(n) type, like: create table prpalk ( sfirmanimi char(100) ); Column types cannot be changed to varchar. Postgres database encoding is unicode. However some columns are in custom encoding which needs to be converted to unicode to be used in .NET. Those column names in database start always with word Custom. I tried Dapper to get data but data contains trailing spaces and

问题 Newbie trying to figure out the best way to design a Postgres db for the following use case scenario. There is an Account table for the business customers and there is a contacts table with a column relationship. account.pk_id, …. contacts.pk_id, contacts.fk_accountid … Thousands of different businesses in the Accounts table will be storing millions of contacts each in the Contacts table. Each contact record will over time belong to between 1 and 100 different categories, lists and products.

问题 Is there an equivalent (or workaround) for the RAISE EXCEPTION statement for the function written below in LANGUAGE sql ? CREATE OR REPLACE FUNCTION fn_interpolation (p_yearinteger integer, p_admin_id integer, p_crop_id integer, p_cropparameter integer) RETURNS TABLE (value double precision, remark text) AS $$ WITH yearvalues AS (SELECT yearinteger, value FROM cropvalues WHERE crops_id = p_crop_id AND admin_id = p_admin_id AND parameter_id = p_cropparameter), I need the function to abort and

问题 My original sql: INSERT INTO clients (name, phone) VALUES ('Vs'emandon', '333026660'); I read about E'' and tried this: INSERT INTO clients (name) VALUES ('VsE'''emandon); But this not working. http://www.sqlfiddle.com/#!15/f717e/2 回答1: Postgres follows the SQL standard. Quote from the manual: To include a single-quote character within a string constant, write two adjacent single quotes, e.g., 'Dianne''s horse' . Note that this is not the same as a double-quote character ( " ). INSERT INTO