database

Database Package Documentation

The database package provides essential functionality for interacting with a Postgres database, including connection management, transaction handling, and repositories. It also includes a migrations folder containing SQL scripts to manage schema changes.

---

Components

Database Service

• Purpose:
  • Manages the connection pool to the Postgres database using pgxpool.
• Features:
  • Configurable parameters (host, port, user, password, database, connection pool size, etc.).
  • Connection health checks.

Migrations

• Purpose:
  • Simplifies database transaction management by abstracting the process of starting, committing, and rolling back transactions.
• Key Features::
  • Implements a TxManager interface with:
    • Begin(ctx context.Context): Starts a new transaction.
    • Execute(ctx context.Context, func(pgx.Tx) error): Executes a transaction block with automatic commit/rollback logic.
• Error and Panic Handling:
  • Ensures rollback in case of errors or panics during transaction execution.
  • Re-throws panics after rollback to preserve original error flow.
• Example Usage:

type ProfileRepository struct {
    database.TxManager
    database.Service
}

func (r ProfileRepository) UpdateWithTx(ctx context.Context, p *profile.Profile) (*profile.Profile, error) {
    // add more db operations here like lock by id or other operations

    err := r.Execute(ctx, func(tx pgx.Tx) error {
        if err := tx.QueryRow(ctx, profileUpdateSql,
            p.FirstName, // $1
            p.LastName,  // $2
            p.Id,        // $3
        ).Scan(&p.Id, &p.CreatedAt, &p.UpdatedAt); err != nil {
            return err
        }
        return nil
    })
return p, err
}

Repositories

• Purpose:
  Encapsulates data access logic to keep it separate from business logic.
• Features:
  • Implements repository patterns for entities, e.g., UserRepository, ProfileRepository.
  • Each repository interacts with the database using the connection pool or a transaction context.