codesnips

postgres

ruby 
class User < ApplicationRecord
  has_many :posts
  has_many :comments

  scope :digest_subscribers, -> {
    where(digest_opt_in: true).where.not(confirmed_at: nil)

Weekly Digest Emails in Rails with a Cron Job and Query Scopes

rails activejob sidekiq-cron
by codesnips 4 tabs
typescript 
export type CheckResult = { name: string; status: 'up' | 'down'; durationMs: number; error?: string };
export type Check = () => Promise<void>;

function withTimeout(fn: Check, ms: number): Promise<void> {
  return new Promise((resolve, reject) => {
    const timer = setTimeout(() => reject(new Error(`timeout after ${ms}ms`)), ms);

Health checks with readiness + liveness

reliability fastify kubernetes
by codesnips 3 tabs
python 
from sqlalchemy import Column, Integer, BigInteger, String
from sqlalchemy.orm import declarative_base

Base = declarative_base()

Optimistic Locking With a Version Column and Bounded Retries in SQLAlchemy

sqlalchemy postgres optimistic-locking
by codesnips 3 tabs
java 
@MappedSuperclass
@FilterDef(
    name = "tenantFilter",
    parameters = @ParamDef(name = "tenantId", type = String.class)
)
@Filter(name = "tenantFilter", condition = "tenant_id = :tenantId")

Enforce Multi-Tenant Row Isolation With Hibernate @Filter Enabled Per Request in Spring Boot

spring-boot hibernate jpa
by codesnips 4 tabs
java 
@Component
public class SalesRollupScheduler {

    private static final Logger log = LoggerFactory.getLogger(SalesRollupScheduler.class);
    private static final int ROLLUP_WINDOW_DAYS = 3;

Roll Up Daily Sales Totals With a Scheduled Spring Batch Upsert via JdbcTemplate

spring-boot jdbctemplate postgres
by codesnips 3 tabs
ruby 
class CreateStripeEvents < ActiveRecord::Migration[7.1]
  def change
    create_table :stripe_events do |t|
      t.string :stripe_event_id, null: false
      t.string :event_type, null: false
      t.string :status, null: false, default: "received"

Idempotent Stripe Webhook Processing in Rails with a Durable Event Log

rails stripe webhooks
by codesnips 4 tabs
ruby 
class RevenueStat
  DEFAULT_RANGE = 30.days

  def initialize(account, range: DEFAULT_RANGE)
    @account = account
    @range = range

Memoized Query Object for a Cached Dashboard Stat in Rails

rails activerecord query-object
by codesnips 3 tabs
java 
package com.shop.inventory;

import jakarta.persistence.*;

@Entity
@Table(name = "inventory_item")

Optimistic Locking on Inventory Updates with @Version and a Retrying Conflict Handler in Spring Boot

spring-boot jpa hibernate
by codesnips 3 tabs
javascript 
const { Pool } = require('pg');
const Cursor = require('pg-cursor');

const pool = new Pool();

async function* streamUsers({ since, batchSize = 500 }) {

Stream a Large JSON Array Response in Node.js Without Buffering

nodejs streams transform-stream
by codesnips 3 tabs
typescript 
import { Writable } from "node:stream";
import type { Pool } from "pg";

interface Row {
  email: string;
  name: string;

Streaming CSV import (Node streams)

streams postgres nodejs
by codesnips 3 tabs
typescript 
import { Type } from 'class-transformer';
import { IsInt, IsOptional, IsString, Max, Min } from 'class-validator';

export class CursorPaginationQuery {
  @IsOptional()
  @IsString()

Cursor-Based Pagination for a TypeORM Repository in NestJS

nestjs typeorm pagination
by codesnips 4 tabs
sql 
CREATE TABLE outbox_deliveries (
    id              BIGSERIAL PRIMARY KEY,
    dedupe_key      TEXT        NOT NULL,
    target_url      TEXT        NOT NULL,
    payload         JSONB       NOT NULL,
    status          TEXT        NOT NULL DEFAULT 'PENDING',

Reliable Webhook Delivery with a Transactional Outbox and Dedupe Key in Spring Boot

spring-boot webhooks outbox-pattern
by codesnips 3 tabs