add restore api

finisher_api.go

@@ -641,13 +641,13 @@ func (db *DB) Restore(values interface{}) (tx *DB) {
 	tx.Statement.Unscoped = true
 	tx.Statement.Parse(values)
 
-	dest := make(map[string]interface{})
-	for _, c := range tx.Statement.Schema.DeleteClauses {
-		fieldName := c.(SoftDeleteDeleteClause).Field.DBName
-		dest[fieldName] = nil
-	}
+	tx.Statement.Dest = make(map[string]interface{})
 
-	tx.Statement.Dest = dest
+	for _, c := range tx.Statement.Schema.DeleteClauses {
+		if optimizer, ok := c.(UnDeleteDester); ok {
+			optimizer.SetUnDeleteDest(tx.Statement)
+		}
+	}
 
 	return tx.callbacks.Update().Execute(tx)
 }

soft_delete.go

@@ -162,3 +162,13 @@ func (sd SoftDeleteDeleteClause) ModifyStatement(stmt *Statement) {
 		stmt.Build("UPDATE", "SET", "WHERE")
 	}
 }
+
+func (sd SoftDeleteDeleteClause) SetUnDeleteDest(stmt *Statement) {
+	if stmt.Unscoped {
+		if sd.Field.DefaultValue != "" {
+			stmt.SetColumn(sd.Field.DBName, clause.Expr{SQL: sd.Field.DefaultValue}, true)
+		} else {
+			stmt.SetColumn(sd.Field.DBName, nil, true)
+		}
+	}
+}

statement.go

@@ -57,6 +57,11 @@ type StatementModifier interface {
 	ModifyStatement(*Statement)
 }
 
+// UnDeleteDester set undelete dest interface
+type UnDeleteDester interface {
+	SetUnDeleteDest(*Statement)
+}
+
 // WriteString write string
 func (stmt *Statement) WriteString(str string) (int, error) {
 	return stmt.SQL.WriteString(str)