feat(BE): approval_workflow, adjusment project_flocks, common, and migration

internal/common/repository/common.exists.repository.go

@@ -0,0 +1,34 @@
+package repository
+
+import (
+	"context"
+
+	"gorm.io/gorm"
+)
+
+// Exists reports whether a record with the given ID exists for type T.
+func Exists[T any](ctx context.Context, db *gorm.DB, id uint) (bool, error) {
+	var count int64
+	if err := db.WithContext(ctx).
+		Model(new(T)).
+		Where("id = ?", id).
+		Count(&count).Error; err != nil {
+		return false, err
+	}
+	return count > 0, nil
+}
+
+func ExistsByName[T any](ctx context.Context, db *gorm.DB, name string, excludeID *uint) (bool, error) {
+	var count int64
+	q := db.WithContext(ctx).
+		Model(new(T)).
+		Where("name = ?", name).
+		Where("deleted_at IS NULL")
+	if excludeID != nil {
+		q = q.Where("id <> ?", *excludeID)
+	}
+	if err := q.Count(&count).Error; err != nil {
+		return false, err
+	}
+	return count > 0, nil
+}