Add method to update (one or multiple rows) specifying the columns to…

… be updated (#437)

* Add method to update (one or multiple rows) specifying the columns to be updated

* Improve testing (more test cases)

executors.go

@@ -362,6 +362,50 @@ func (c *Connection) Update(model interface{}, excludeColumns ...string) error {
 	})
 }
 
+// UpdateColumns writes changes from an entry to the database, including only the given columns
+// or all columns if no column names are provided.
+// It updates the `updated_at` column automatically.
+//
+// If model is a slice, each item of the slice is updated in the database.
+func (c *Connection) UpdateColumns(model interface{}, columnNames ...string) error {
+	sm := &Model{Value: model}
+	return sm.iterate(func(m *Model) error {
+		return c.timeFunc("Update", func() error {
+			var err error
+
+			if err = m.beforeSave(c); err != nil {
+				return err
+			}
+			if err = m.beforeUpdate(c); err != nil {
+				return err
+			}
+
+			tn := m.TableName()
+
+			cols := columns.Columns{}
+			if len(columnNames) > 0 && tn == sm.TableName() {
+				cols = columns.NewColumnsWithAlias(tn, m.As)
+				cols.Add(columnNames...)
+
+			} else {
+				cols = columns.ForStructWithAlias(model, tn, m.As)
+			}
+			cols.Remove("id", "created_at")
+
+			m.touchUpdatedAt()
+
+			if err = c.Dialect.Update(c.Store, m, cols); err != nil {
+				return err
+			}
+			if err = m.afterUpdate(c); err != nil {
+				return err
+			}
+
+			return m.afterSave(c)
+		})
+	})
+}
+
 // Destroy deletes a given entry from the database.
 //
 // If model is a slice, each item of the slice is deleted from the database.

executors_test.go

@@ -1229,6 +1229,123 @@ func Test_Update(t *testing.T) {
 	})
 }
 
+func Test_UpdateColumns(t *testing.T) {
+	if PDB == nil {
+		t.Skip("skipping integration tests")
+	}
+	transaction(func(tx *Connection) {
+		r := require.New(t)
+
+		user := User{Name: nulls.NewString("Mark")}
+		tx.Create(&user)
+
+		r.NotZero(user.CreatedAt)
+		r.NotZero(user.UpdatedAt)
+
+		user.Name.String = "Fulano"
+		user.UserName = "Fulano"
+		err := tx.UpdateColumns(&user, "user_name") // Update UserName field/column only
+		r.NoError(err)
+
+		r.NoError(tx.Reload(&user))
+		r.Equal(user.Name.String, "Mark") // Name column should not be updated
+		r.Equal(user.UserName, "Fulano")
+	})
+}
+
+func Test_UpdateColumns_MultipleColumns(t *testing.T) {
+	if PDB == nil {
+		t.Skip("skipping integration tests")
+	}
+	transaction(func(tx *Connection) {
+		r := require.New(t)
+
+		user := User{Name: nulls.NewString("Mark"), UserName: "Sagan", Email: "test@example.com"}
+		tx.Create(&user)
+
+		r.NotZero(user.CreatedAt)
+		r.NotZero(user.UpdatedAt)
+
+		user.Name.String = "Ping"
+		user.UserName = "Pong"
+		user.Email = "fulano@example"
+		err := tx.UpdateColumns(&user, "name", "user_name") // Update multiple columns
+		r.NoError(err)
+
+		r.NoError(tx.Reload(&user))
+		r.Equal(user.Name.String, "Ping")
+		r.Equal(user.UserName, "Pong")
+		r.Equal(user.Email, "test@example.com") // Email should not be updated
+	})
+}
+
+func Test_UpdateColumns_All(t *testing.T) {
+	if PDB == nil {
+		t.Skip("skipping integration tests")
+	}
+	transaction(func(tx *Connection) {
+		r := require.New(t)
+
+		user := User{Name: nulls.NewString("Mark"), UserName: "Sagan"}
+		tx.Create(&user)
+
+		r.NotZero(user.CreatedAt)
+		r.NotZero(user.UpdatedAt)
+
+		user.Name.String = "Ping"
+		user.UserName = "Pong"
+		user.Email = "ping@pong.com"
+		err := tx.UpdateColumns(&user) // Update all columns
+		r.NoError(err)
+
+		r.NoError(tx.Reload(&user))
+		r.Equal(user.Name.String, "Ping")
+		r.Equal(user.UserName, "Pong")
+		r.Equal(user.Email, "ping@pong.com")
+	})
+}
+
+func Test_UpdateColumns_With_Slice(t *testing.T) {
+	if PDB == nil {
+		t.Skip("skipping integration tests")
+	}
+	transaction(func(tx *Connection) {
+		r := require.New(t)
+
+		user := Users{
+			{
+				Name:     nulls.NewString("Mark"),
+				UserName: "Ping",
+			},
+			{
+				Name:     nulls.NewString("Larry"),
+				UserName: "Pong",
+			},
+		}
+		tx.Create(&user)
+
+		r.NotZero(user[0].CreatedAt)
+		r.NotZero(user[0].UpdatedAt)
+
+		r.NotZero(user[1].CreatedAt)
+		r.NotZero(user[1].UpdatedAt)
+
+		user[0].Name.String = "Fulano"
+		user[0].UserName = "Thor"
+		user[1].Name.String = "Fulana"
+		user[1].UserName = "Freya"
+
+		err := tx.UpdateColumns(&user, "name") // Update Name field/column only
+		r.NoError(err)
+
+		r.NoError(tx.Reload(&user))
+		r.Equal(user[0].Name.String, "Fulano")
+		r.Equal(user[0].UserName, "Ping") // UserName should not be updated
+		r.Equal(user[1].Name.String, "Fulana")
+		r.Equal(user[1].UserName, "Pong") // UserName should not be updated
+	})
+}
+
 func Test_Update_With_Slice(t *testing.T) {
 	if PDB == nil {
 		t.Skip("skipping integration tests")