GORM Provider

Overview

The GORM provider (github.com/lemmego/gpagorm) is the production-ready SQL provider. It wraps GORM to provide the full GPA Repository[T] interface with migration support.

Setup

import (
    "github.com/lemmego/gpa"
    "github.com/lemmego/gpagorm"
)

config := gpa.Config{
    Driver:   "postgres",
    Host:     "localhost",
    Port:     5432,
    Username: "user",
    Password: "password",
    Database: "mydb",
}

provider, err := gpagorm.NewProvider(config)

Supported Drivers

PostgreSQL
MySQL
SQLite
SQL Server / MSSQL

Connection Pooling

GORM connection pooling is configured through the Config:

config := gpa.Config{
    Driver:        "mysql",
    MaxOpenConns:  25,
    MaxIdleConns:  10,
    ConnMaxLifetime: 5 * time.Minute,
    Options: map[string]interface{}{
        "gorm": map[string]interface{}{
            "log_level": "info",
            "singular_table": true,
        },
    },
}

Creating Repositories

// From the registry (auto-resolves the "default" GORM provider)
userRepo := gpagorm.GetRepository[User]()

// From a specific provider instance
userRepo := gpagorm.GetRepository[User](provider)

// From a named registry instance
userRepo := gpagorm.GetRepository[User]("primary")

Repository Type

The GORM repository implements gpa.MigratableRepository[T], which includes:

Full Repository[T] CRUD
SQLRepository[T] (raw SQL, DDL, eager loading)
MigratableRepository[T] (auto-migration, migration status, table info)

// Pattern with typed wrapper
type UserRepository struct {
    gpa.MigratableRepository[User]
}

func NewUserRepository() *UserRepository {
    repo := gpagorm.GetRepository[User]()
    return &UserRepository{repo}
}

Hooks

The GORM provider supports all GPA entity hooks:

type User struct {
    ID        uint
    Name      string
    Email     string
    CreatedAt time.Time
    UpdatedAt time.Time
}

func (u *User) Validate(ctx context.Context) error {
    if u.Email == "" {
        return gpa.NewError(gpa.ErrorTypeValidation, "email required")
    }
    return nil
}

func (u *User) BeforeCreate(ctx context.Context) error {
    u.Email = strings.ToLower(u.Email)
    u.CreatedAt = time.Now()
    u.UpdatedAt = time.Now()
    return nil
}

func (u *User) AfterFind(ctx context.Context) error {
    // Post-load processing
    return nil
}

Hook execution order: Validate → BeforeCreate → DB Insert → AfterCreate

Features

Feature	Support
Transactions + Savepoints	Yes
Raw SQL	Yes
Eager Loading	Yes (Preload, FindWithRelations)
Auto Migration	Yes (AutoMigrate, MigrateTable)
Index Management	Yes (CreateIndex, DropIndex)
Batch Operations	Yes (CreateBatch with size 100)
SQL Injection Protection	Yes (regex-based field validation)
Error Mapping	Yes (GORM errors → GPA typed errors)

Raw SQL & DDL Bun Provider