database

README

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.

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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.

Documentation

Index

• func GetDialect() string
• func GetMigrationFS() embed.FS
• type Service
  • func New(cfg config.DatabaseConfig) Service
• type TxManager
  • func NewTxManager(db Service) TxManager

Functions

func GetDialect

func GetDialect() string

func GetMigrationFS

func GetMigrationFS() embed.FS

Types

type Service

type Service interface {
	// Health returns a map of health status information.
	// The keys and values in the map are service-specific.
	Health(ctx context.Context) map[string]string

	// Close terminates the database connection.
	// It returns an error if the connection cannot be closed.
	Close() error

	// DB returns the database connection.
	DB() *sql.DB

	// Pool returns the pgx connection pool.
	Pool() *pgxpool.Pool
}

Service represents a service that interacts with a database.

func New

func New(cfg config.DatabaseConfig) Service

type TxManager

type TxManager interface {
	Begin(context.Context) (pgx.Tx, error)
	Execute(context.Context, func(pgx.Tx) error) error
}

TxManager defines a method to execute a transaction from Begin until Commit or Rollback.

func NewTxManager

func NewTxManager(db Service) TxManager