dao for future

database/basemapper.go

@@ -0,0 +1,76 @@
+package database
+
+import (
+	"errors"
+
+	"gorm.io/gorm"
+)
+
+type BaseDAO[T any] struct {
+	db *gorm.DB
+}
+
+func NewDAO[T any](db *gorm.DB) *BaseDAO[T] {
+	return &BaseDAO[T]{
+		db: db,
+	}
+}
+
+/* Single Table Operations */
+
+func (b *BaseDAO[T]) GetAll(e T) ([]T, error) {
+	var r []T
+	if err := b.db.Find(&r, e).Error; err != nil {
+		return nil, err
+	}
+	return r, nil
+}
+
+func (b *BaseDAO[T]) GetOne(e T) (T, error) {
+	var r T
+	if err := b.db.First(&r, e).Error; err != nil {
+		return r, err
+	}
+	return r, nil
+}
+
+func (b *BaseDAO[T]) GetSome(e T, limit, offset int) ([]T, error) {
+	var r []T
+	if err := b.db.Find(&r, e).Limit(limit).Offset(offset).Error; err != nil {
+		return nil, err
+	}
+	return r, nil
+}
+
+func (b *BaseDAO[T]) Create(e T) (T, error) {
+	if err := b.db.Create(&e).Error; err != nil {
+		return e, err
+	}
+	return e, nil
+}
+
+func (b *BaseDAO[T]) Update(e T) (T, error) {
+	if err := b.db.Updates(&e).Error; err != nil {
+		return e, err
+	}
+	return e, nil
+}
+
+func (b *BaseDAO[T]) UpdateOrCreate(e T) (T, error) {
+	var r T
+	err := b.db.First(&r, e).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return b.Create(e)
+		}
+		return e, err
+	}
+	return b.Update(e)
+}
+
+func (b *BaseDAO[T]) Delete(e T) error {
+	if err := b.db.Delete(e).Error; err != nil {
+		return err
+	}
+	return nil
+}