codesnips

repository-pattern

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
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