Entity: Return the error if an update statement has failed #4504 #4505

Signed-off-by: Michael Mayer <michael@photoprism.app>

internal/entity/entity_update.go

@@ -4,12 +4,13 @@ import (
 	"fmt"
 )
 
-// Update updates an existing record in the database.
+// Update updates the values of an existing database record.
 func Update(m interface{}, keyNames ...string) (err error) {
-	// Unscoped so soft-deleted records can still be updated.
+	// Use an unscoped *gorm.DB connection, so that
+	// soft-deleted database records can also be updated.
 	db := UnscopedDb()
 
-	// New entity?
+	// Return if the record has not been created yet.
 	if db.NewRecord(m) {
 		return fmt.Errorf("new record")
 	}
@@ -17,20 +18,23 @@ func Update(m interface{}, keyNames ...string) (err error) {
 	// Extract interface slice with all values including zero.
 	values, keys, err := ModelValues(m, keyNames...)
 
-	// Has keys and values?
+	// Check if the number of keys matches the number of values.
 	if err != nil {
 		return err
 	} else if len(keys) != len(keyNames) {
 		return fmt.Errorf("record keys missing")
 	}
 
-	// Update values.
+	// Execute update statement.
 	result := db.Model(m).Updates(values)
 
-	// Successful?
-	if result.Error != nil {
+	// Return an error if the update has failed.
+	if err = result.Error; err != nil {
 		return err
-	} else if result.RowsAffected > 1 {
+	}
+
+	// Verify number of updated rows.
+	if result.RowsAffected > 1 {
 		log.Debugf("entity: updated statement affected more than one record - you may have found a bug")
 		return nil
 	} else if result.RowsAffected == 1 {
@@ -39,5 +43,5 @@ func Update(m interface{}, keyNames ...string) (err error) {
 		return fmt.Errorf("record not found")
 	}
 
-	return err
+	return nil
 }