feat(delete): allow deletion of models (#37)

Signed-off-by: Geoffrey Bauduin <[email protected]>

model.go

@@ -13,48 +13,84 @@ import (
 
 // Model is the interface every model should implement from
 type Model interface {
+	// GetDBP should return the DBProvider tied to this model
 	GetDBP() DBProvider
+	// SetDBP allows setting a DBProvider to the model, then returned by GetDBP
 	SetDBP(dbp DBProvider)
+	// Save allows saving the model
 	Save() error
+	// Load loads the model from database given the current struct
 	Load(dbp DBProvider) error
+	// Delete removes the model from database
 	Delete() error
+	// DBHookBeforeInsert is a hook called before performing a DB insertion
 	DBHookBeforeInsert() error
+	// DBHookBeforeUpdate is a hook called before performing a DB update
 	DBHookBeforeUpdate() error
+	// DBHookBeforeDelete is a hook called before performing a DB delete
+	DBHookBeforeDelete() error
 }
 
 // DatabaseModel is the struct every model should compose
 type DatabaseModel struct {
 	dbp DBProvider `db:"-"`
 }
 
+// SetDBP allows setting a DBProvider to the model, then returned by GetDBP
 func (dm *DatabaseModel) SetDBP(dbp DBProvider) {
 	dm.dbp = dbp
 }
 
+// GetDBP should return the DBProvider tied to this model
 func (dm *DatabaseModel) GetDBP() DBProvider {
 	return dm.dbp
 }
 
+// Save allows saving the model
+// In order to be usable, this function needs to be redfined by each
+// composition of this structure
 func (dm *DatabaseModel) Save() error {
 	return errors.NotImplementedf("Save")
 }
 
+// Load loads the model from database given the current struct
+// In order to be usable, this function needs to be redfined by each
+// composition of this structure
 func (dm *DatabaseModel) Load(dbp DBProvider) error {
 	return errors.NotImplementedf("Load")
 }
 
+// Delete removes the model from database
+// In order to be usable, this function needs to be redfined by each
+// composition of this structure
 func (dm *DatabaseModel) Delete() error {
 	return errors.NotImplementedf("Delete")
 }
 
+// DBHookBeforeInsert is a hook called before performing a DB insertion
+// By default, this function does not do anything. If needed, you will have
+// to implement this function in your structure composing this one
+// in order to have your code hook executed
 func (dm *DatabaseModel) DBHookBeforeInsert() error {
 	return nil
 }
 
+// DBHookBeforeUpdate is a hook called before performing a DB update
+// By default, this function does not do anything. If needed, you will have
+// to implement this function in your structure composing this one
+// in order to have your code hook executed
 func (dm *DatabaseModel) DBHookBeforeUpdate() error {
 	return nil
 }
 
+// DBHookBeforeDelete is a hook called before performing a DB delete
+// By default, this function does not do anything. If needed, you will have
+// to implement this function in your structure composing this one
+// in order to have your code hook executed
+func (dm *DatabaseModel) DBHookBeforeDelete() error {
+	return nil
+}
+
 type cnt struct {
 	Count uint64 `db:"count"`
 }
@@ -472,3 +508,13 @@ func getFieldInModel(m Model, tag, equals string) (int, string) {
 	}
 	return -1, ""
 }
+
+// GenericDelete will delete the provided model from its database
+// Returns the number of rows deleted
+func GenericDelete(m Model) (int64, error) {
+	err := m.DBHookBeforeDelete()
+	if err != nil {
+		return 0, err
+	}
+	return m.GetDBP().DB().Delete(m)
+}

model_test.go

@@ -485,3 +485,58 @@ func TestSubqueryloadWithInvalidTypeReturned(t *testing.T) {
 	assert.Error(t, err)
 	assert.Contains(t, err.Error(), "a subquery returned a non-array and non-slice type 'ptr', which is not handled")
 }
+
+func TestGenericDelete(t *testing.T) {
+	killDb, err := testdata.SetupTestDatabase("test")
+	defer killDb()
+	assert.NoError(t, err)
+	dbp, err := yaorm.NewDBProvider(context.TODO(), "test")
+	assert.NoError(t, err)
+	category := &testdata.Category{Name: "category"}
+	saveModel(t, dbp, category)
+	category2 := &testdata.Category{Name: "category"}
+	saveModel(t, dbp, category2)
+	rows, errDelete := yaorm.GenericDelete(category)
+	assert.NoError(t, errDelete)
+	assert.Equal(t, int64(1), rows)
+	rows, errDelete = yaorm.GenericDelete(category)
+	assert.NoError(t, errDelete)
+	assert.Equal(t, int64(0), rows)
+	notFound, err := yaorm.GenericSelectOne(dbp, testdata.NewCategoryFilter().ID(yaormfilter.Equals(category.ID)))
+	assert.Error(t, err)
+	assert.Nil(t, notFound)
+	assert.True(t, errors.IsNotFound(err))
+	found, err := yaorm.GenericSelectOne(dbp, testdata.NewCategoryFilter().ID(yaormfilter.Equals(category2.ID)))
+	assert.NoError(t, err)
+	assert.NotNil(t, found)
+}
+
+func TestGenericDelete_MultiplePrimaryKeys(t *testing.T) {
+	killDb, err := testdata.SetupTestDatabase("test")
+	defer killDb()
+	assert.NoError(t, err)
+	dbp, err := yaorm.NewDBProvider(context.TODO(), "test")
+	assert.NoError(t, err)
+	category := &testdata.Category{Name: "category"}
+	saveModel(t, dbp, category)
+	post := &testdata.Post{Subject: "subject", CategoryID: category.ID}
+	saveModel(t, dbp, post)
+	tag := &testdata.Tag{Tag: "tag"}
+	saveModel(t, dbp, tag)
+	tag2 := &testdata.Tag{Tag: "tag2"}
+	saveModel(t, dbp, tag2)
+	posttag := &testdata.PostTag{TagID: tag.ID, PostID: post.ID}
+	saveModel(t, dbp, posttag)
+	posttag2 := &testdata.PostTag{TagID: tag2.ID, PostID: post.ID}
+	saveModel(t, dbp, posttag2)
+	rows, err := yaorm.GenericDelete(posttag)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(1), rows)
+	rows, err = yaorm.GenericDelete(posttag)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(0), rows)
+	listTags, err := yaorm.GenericSelectAll(dbp, testdata.NewPostTagFilter().PostID(yaormfilter.Equals(post.ID)))
+	assert.NoError(t, err)
+	assert.Len(t, listTags, 1)
+	assert.Equal(t, tag2.ID, listTags[0].(*testdata.PostTag).TagID)
+}