codesnips

transactions

rust 
use std::fs;
use std::path::Path;

#[derive(Debug, Clone)]
pub struct Migration {
    pub version: i64,

Sequential Schema Migrations With Version Tracking in Rust and Postgres

migrations postgres sql
by codesnips 3 tabs
java 
package com.example.reference;

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import jakarta.persistence.Table;

Seed Reference Data at Boot with a Spring Boot ApplicationRunner

spring-boot seeding reference-data
by codesnips 4 tabs
ruby 
class ImportResult
  RowError = Struct.new(:line, :messages)

  attr_reader :imported, :row_errors

  def initialize

Streaming CSV Product Import With Per-Row Validation and Error Reporting in Rails

rails csv service-object
by codesnips 3 tabs
java 
package com.example.orders.event;

import java.math.BigDecimal;
import java.time.Instant;

public final class OrderPlacedEvent {

Publishing Domain Events After Commit with @TransactionalEventListener in Spring Boot

spring-boot spring-events transactions
by codesnips 4 tabs
python 
from django.conf import settings
from django.db.models.signals import post_save
from django.dispatch import receiver

from .models import EmailOutbox

Sending Welcome Emails via a Django post_save Signal and Outbox Worker

django signals email
by codesnips 4 tabs
go 
package bank

import "errors"

var ErrVersionConflict = errors.New("optimistic lock: version conflict")
var ErrInsufficientFunds = errors.New("insufficient funds")

Optimistic Locking in Go With a Version Column on UPDATE

optimistic-locking concurrency postgres
by codesnips 3 tabs
sql 
CREATE TYPE outbox_status AS ENUM ('pending', 'retry', 'processing', 'done', 'dead');

CREATE TABLE outbox_events (
    id           BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    dedupe_key   TEXT        NOT NULL,
    topic        TEXT        NOT NULL,

Atomic “Read + Mark Processed” with UPDATE … RETURNING

postgres concurrency reliability
by codesnips 3 tabs
java 
package com.shop.orders.events;

import java.math.BigDecimal;
import java.time.Instant;

public record OrderPlacedEvent(

Transactional Domain Events With Spring's ApplicationEventPublisher and @TransactionalEventListener

spring spring-boot domain-events
by codesnips 4 tabs
java 
@Configuration
public class TxConfig {

    @Bean
    public PlatformTransactionManager transactionManager(DataSource dataSource) {
        DataSourceTransactionManager tm = new DataSourceTransactionManager(dataSource);

Multi-Step Order Flow With Spring TransactionTemplate and Savepoint Rollback

spring-boot transactions transactiontemplate
by codesnips 3 tabs
go 
package store

import (
  "context"

  "github.com/jackc/pgx/v5"

Row-level locking with SELECT ... FOR UPDATE in a transaction

go postgres transactions
by Leah Thompson 1 tab
typescript 
import { QueryResultRow } from 'pg';
import { pool, Queryable } from './db';

export abstract class BaseRepository<T extends QueryResultRow> {
  protected abstract readonly table: string;

Repository pattern for DB access (small, pragmatic)

node postgres architecture
by codesnips 4 tabs
ruby 
class Order < ApplicationRecord
  class InvalidTransition < StandardError; end

  enum status: { pending: 0, paid: 1, shipped: 2, cancelled: 3 }

  has_many :order_transitions, -> { order(:created_at) }, dependent: :destroy

Order State Machine With Guarded Transitions and an Audit Trail in Rails

rails state-machine activerecord
by codesnips 3 tabs