codesnips

postgres

typescript 
import { Pool } from "pg";

async function keyFor(pool: Pool, name: string): Promise<string> {
  const { rows } = await pool.query<{ key: string }>(
    "SELECT hashtextextended($1, 0) AS key",
    [name]

Postgres advisory lock for one-at-a-time work

postgres concurrency reliability
by codesnips 3 tabs
rust 
use base64::{engine::general_purpose::URL_SAFE_NO_PAD, Engine};
use serde::{Deserialize, Serialize};
use time::OffsetDateTime;
use uuid::Uuid;

#[derive(Debug, Clone, Serialize, Deserialize)]

Cursor-Paginated Streaming REST Endpoint in Axum with Keyset Pagination

axum rust pagination
by codesnips 3 tabs
ruby 
class Order < ApplicationRecord
  include TransactionalEnqueue

  belongs_to :customer
  has_many :line_items, dependent: :destroy

Transaction-Safe After-Commit Hook (Avoid Ghost Jobs)

rails activerecord background-jobs
by codesnips 4 tabs
ruby 
class AddSlugToArticles < ActiveRecord::Migration[7.1]
  def change
    add_column :articles, :slug, :string, null: false, default: ""
    add_index :articles, :slug, unique: true

    # Backfill existing rows before the unique index is relied upon in code.

Generate Unique URL Slugs in Rails with before_validation and a friendly Controller Lookup

rails activerecord slugs
by codesnips 3 tabs
python 
import datetime as dt

from sqlalchemy import Column, DateTime, Integer, String, UniqueConstraint
from sqlalchemy.orm import declarative_base

Base = declarative_base()

Idempotent Webhook Ingestion With a Postgres Dedupe Store in FastAPI

fastapi webhooks idempotency
by codesnips 3 tabs
ruby 
class CreateAuditLogs < ActiveRecord::Migration[7.1]
  def change
    create_table :audit_logs do |t|
      t.references :auditable, polymorphic: true, null: false
      t.string :actor
      t.string :action, null: false

Audit Trail with JSON Diff (Minimal, Useful)

rails activerecord auditing
by codesnips 4 tabs
python 
from datetime import datetime
from app.extensions import db


class IdempotencyKey(db.Model):
    __tablename__ = "idempotency_keys"

Idempotency-Key Deduplication for POST Requests in a Flask Blueprint

flask idempotency postgres
by codesnips 3 tabs
python 
from django.db import models
from django.utils import timezone


class WebhookEvent(models.Model):
    class Status(models.TextChoices):

Idempotent Stripe Webhook Handling in Django with a Unique Event-ID Constraint

django webhooks idempotency
by codesnips 3 tabs
ruby 
class CreateCustomerRevenueSummaries < ActiveRecord::Migration[7.0]
  def change
    create_view :customer_revenue_summaries, materialized: true, version: 1

    add_index :customer_revenue_summaries,
              :customer_id,

Database Views for Read Models

rails postgres performance
by codesnips 4 tabs
go 
package store

import (
  "context"

  sq "github.com/Masterminds/squirrel"

Safe dynamic SQL with squirrel (optional filters, stable ordering)

go sql postgres
by Leah Thompson 1 tab
sql 
CREATE TABLE subscriptions (
    id                  BIGGENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    customer_id         BIGINT       NOT NULL,
    plan_code           TEXT         NOT NULL,
    status              TEXT         NOT NULL DEFAULT 'active',
    current_period_end  TIMESTAMPTZ  NOT NULL,

Partial index for “active” rows in Postgres

postgres performance sql
by codesnips 3 tabs
sql 
-- Step 1: add the column nullable, no default.
-- Catalog-only change in Postgres 11+, returns instantly.
ALTER TABLE orders
  ADD COLUMN currency text;

-- Optional: keep the lock attempt bounded so a long-running

SQL migration safety: add column nullable, backfill, then constrain

postgres migrations reliability
by codesnips 3 tabs