Refactoring API for plugin system

callback_create.go

@@ -56,7 +56,7 @@ func Create(scope *Scope) {
 
 		// execute create sql
 		if scope.Dialect().SupportLastInsertId() {
-			if result, err := scope.DB().Exec(scope.Sql, scope.SqlVars...); scope.Err(err) == nil {
+			if result, err := scope.SqlDB().Exec(scope.Sql, scope.SqlVars...); scope.Err(err) == nil {
 				id, err := result.LastInsertId()
 				if scope.Err(err) == nil {
 					scope.db.RowsAffected, _ = result.RowsAffected()
@@ -67,10 +67,10 @@ func Create(scope *Scope) {
 			}
 		} else {
 			if primaryField == nil {
-				if results, err := scope.DB().Exec(scope.Sql, scope.SqlVars...); err != nil {
+				if results, err := scope.SqlDB().Exec(scope.Sql, scope.SqlVars...); err != nil {
 					scope.db.RowsAffected, _ = results.RowsAffected()
 				}
-			} else if scope.Err(scope.DB().QueryRow(scope.Sql, scope.SqlVars...).Scan(primaryField.Field.Addr().Interface())) == nil {
+			} else if scope.Err(scope.SqlDB().QueryRow(scope.Sql, scope.SqlVars...).Scan(primaryField.Field.Addr().Interface())) == nil {
 				scope.db.RowsAffected = 1
 			}
 		}

callback_query.go

@@ -40,7 +40,7 @@ func Query(scope *Scope) {
 	scope.prepareQuerySql()
 
 	if !scope.HasError() {
-		rows, err := scope.DB().Query(scope.Sql, scope.SqlVars...)
+		rows, err := scope.SqlDB().Query(scope.Sql, scope.SqlVars...)
 		scope.db.RowsAffected = 0
 
 		if scope.Err(err) != nil {

common_dialect.go

@@ -90,7 +90,7 @@ func (s *commonDialect) HasTable(scope *Scope, tableName string) bool {
 	newScope.Raw(fmt.Sprintf("SELECT count(*) FROM INFORMATION_SCHEMA.tables where table_name = %v AND table_schema = %v",
 		newScope.AddToVars(tableName),
 		newScope.AddToVars(s.databaseName(scope))))
-	newScope.DB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
 	return count > 0
 }
 
@@ -102,7 +102,7 @@ func (s *commonDialect) HasColumn(scope *Scope, tableName string, columnName str
 		newScope.AddToVars(tableName),
 		newScope.AddToVars(columnName),
 	))
-	newScope.DB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
 	return count > 0
 }
 

main.go

@@ -84,10 +84,25 @@ func (s *DB) DB() *sql.DB {
 	return s.db.(*sql.DB)
 }
 
-func (s *DB) New() *DB {
-	clone := s.clone()
-	clone.search = nil
-	return clone
+// NewScope create scope for callbacks, including DB's search information
+func (db *DB) NewScope(value interface{}) *Scope {
+	dbClone := db.clone()
+	dbClone.Value = value
+	return &Scope{db: dbClone, Search: dbClone.search, Value: value}
+}
+
+func (s *DB) FreshDB() *DB {
+	newDB := &DB{
+		dialect:      s.dialect,
+		logger:       s.logger,
+		callback:     s.parent.callback.clone(),
+		source:       s.source,
+		values:       map[string]interface{}{},
+		db:           s.db,
+		ModelStructs: map[reflect.Type]*ModelStruct{},
+	}
+	newDB.parent = newDB
+	return newDB
 }
 
 // CommonDB Return the underlying sql.DB or sql.Tx instance.

mssql.go

@@ -92,7 +92,7 @@ func (s *mssql) HasTable(scope *Scope, tableName string) bool {
 	newScope.Raw(fmt.Sprintf("SELECT count(*) FROM INFORMATION_SCHEMA.tables where table_name = %v AND table_catalog = %v",
 		newScope.AddToVars(tableName),
 		newScope.AddToVars(s.databaseName(scope))))
-	newScope.DB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
 	return count > 0
 }
 
@@ -104,7 +104,7 @@ func (s *mssql) HasColumn(scope *Scope, tableName string, columnName string) boo
 		newScope.AddToVars(tableName),
 		newScope.AddToVars(columnName),
 	))
-	newScope.DB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
 	return count > 0
 }
 

mysql.go

@@ -90,7 +90,7 @@ func (s *mysql) HasTable(scope *Scope, tableName string) bool {
 	newScope.Raw(fmt.Sprintf("SELECT count(*) FROM INFORMATION_SCHEMA.tables where table_name = %v AND table_schema = %v",
 		newScope.AddToVars(tableName),
 		newScope.AddToVars(s.databaseName(scope))))
-	newScope.DB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
 	return count > 0
 }
 
@@ -102,7 +102,7 @@ func (s *mysql) HasColumn(scope *Scope, tableName string, columnName string) boo
 		newScope.AddToVars(tableName),
 		newScope.AddToVars(columnName),
 	))
-	newScope.DB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
 	return count > 0
 }
 

postgres.go

@@ -83,7 +83,7 @@ func (s *postgres) HasTable(scope *Scope, tableName string) bool {
 	var count int
 	newScope := scope.New(nil)
 	newScope.Raw(fmt.Sprintf("SELECT count(*) FROM INFORMATION_SCHEMA.tables where table_name = %v and table_type = 'BASE TABLE'", newScope.AddToVars(tableName)))
-	newScope.DB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
 	return count > 0
 }
 
@@ -94,7 +94,7 @@ func (s *postgres) HasColumn(scope *Scope, tableName string, columnName string)
 		newScope.AddToVars(tableName),
 		newScope.AddToVars(columnName),
 	))
-	newScope.DB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
 	return count > 0
 }
 

scope.go

@@ -33,13 +33,6 @@ func (scope *Scope) IndirectValue() reflect.Value {
 	return *scope.indirectValue
 }
 
-// NewScope create scope for callbacks, including DB's search information
-func (db *DB) NewScope(value interface{}) *Scope {
-	dbClone := db.clone()
-	dbClone.Value = value
-	return &Scope{db: dbClone, Search: dbClone.search, Value: value}
-}
-
 func (scope *Scope) NeedPtr() *Scope {
 	reflectKind := reflect.ValueOf(scope.Value).Kind()
 	if !((reflectKind == reflect.Invalid) || (reflectKind == reflect.Ptr)) {
@@ -52,16 +45,21 @@ func (scope *Scope) NeedPtr() *Scope {
 
 // New create a new Scope without search information
 func (scope *Scope) New(value interface{}) *Scope {
-	return &Scope{db: scope.db, Search: &search{}, Value: value}
+	return &Scope{db: scope.NewDB(), Search: &search{}, Value: value}
 }
 
 // NewDB create a new DB without search information
 func (scope *Scope) NewDB() *DB {
-	return scope.db.New()
+	if scope.db != nil {
+		db := scope.db.clone()
+		db.search = nil
+		return db
+	}
+	return nil
 }
 
-// DB get *sql.DB
-func (scope *Scope) DB() sqlCommon {
+// SqlDB return *sql.DB
+func (scope *Scope) SqlDB() sqlCommon {
 	return scope.db.db
 }
 
@@ -73,9 +71,8 @@ func (scope *Scope) SkipLeft() {
 // Quote used to quote database column name according to database dialect
 func (scope *Scope) Quote(str string) string {
 	if strings.Index(str, ".") != -1 {
-		strs := strings.Split(str, ".")
 		newStrs := []string{}
-		for _, str := range strs {
+		for _, str := range strings.Split(str, ".") {
 			newStrs = append(newStrs, scope.Dialect().Quote(str))
 		}
 		return strings.Join(newStrs, ".")
@@ -176,13 +173,13 @@ func (scope *Scope) CallMethod(name string, checkError bool) {
 			case func(s *Scope):
 				f(scope)
 			case func(s *DB):
-				f(scope.db.New())
+				f(scope.NewDB())
 			case func() error:
 				scope.Err(f())
 			case func(s *Scope) error:
 				scope.Err(f(scope))
 			case func(s *DB) error:
-				scope.Err(f(scope.db.New()))
+				scope.Err(f(scope.NewDB()))
 			default:
 				scope.Err(fmt.Errorf("unsupported function %v", name))
 			}
@@ -229,12 +226,7 @@ func (scope *Scope) QuotedTableName() string {
 		return scope.Search.TableName
 	}
 
-	keys := strings.Split(scope.TableName(), ".")
-	for i, v := range keys {
-		keys[i] = scope.Quote(v)
-	}
-	return strings.Join(keys, ".")
-
+	return scope.Quote(scope.TableName())
 }
 
 // CombinedConditionSql get combined condition sql
@@ -263,7 +255,7 @@ func (scope *Scope) Exec() *Scope {
 	defer scope.Trace(NowFunc())
 
 	if !scope.HasError() {
-		if result, err := scope.DB().Exec(scope.Sql, scope.SqlVars...); scope.Err(err) == nil {
+		if result, err := scope.SqlDB().Exec(scope.Sql, scope.SqlVars...); scope.Err(err) == nil {
 			if count, err := result.RowsAffected(); err == nil {
 				scope.db.RowsAffected = count
 			}
@@ -308,7 +300,7 @@ func (scope *Scope) Trace(t time.Time) {
 
 // Begin start a transaction
 func (scope *Scope) Begin() *Scope {
-	if db, ok := scope.DB().(sqlDb); ok {
+	if db, ok := scope.SqlDB().(sqlDb); ok {
 		if tx, err := db.Begin(); err == nil {
 			scope.db.db = interface{}(tx).(sqlCommon)
 			scope.InstanceSet("gorm:started_transaction", true)

scope_private.go

@@ -338,13 +338,13 @@ func (scope *Scope) updatedAttrsWithValues(values map[string]interface{}, ignore
 func (scope *Scope) row() *sql.Row {
 	defer scope.Trace(NowFunc())
 	scope.prepareQuerySql()
-	return scope.DB().QueryRow(scope.Sql, scope.SqlVars...)
+	return scope.SqlDB().QueryRow(scope.Sql, scope.SqlVars...)
 }
 
 func (scope *Scope) rows() (*sql.Rows, error) {
 	defer scope.Trace(NowFunc())
 	scope.prepareQuerySql()
-	return scope.DB().Query(scope.Sql, scope.SqlVars...)
+	return scope.SqlDB().Query(scope.Sql, scope.SqlVars...)
 }
 
 func (scope *Scope) initialize() *Scope {

sqlite3.go

@@ -70,13 +70,13 @@ func (s *sqlite3) Quote(key string) string {
 
 func (s *sqlite3) HasTable(scope *Scope, tableName string) bool {
 	var count int
-	scope.DB().QueryRow(fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE type='table' AND name='%v';", tableName)).Scan(&count)
+	scope.SqlDB().QueryRow(fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE type='table' AND name='%v';", tableName)).Scan(&count)
 	return count > 0
 }
 
 func (s *sqlite3) HasColumn(scope *Scope, tableName string, columnName string) bool {
 	var count int
-	scope.DB().QueryRow(fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE tbl_name = '%v' AND (sql LIKE '%%(\"%v\" %%' OR sql LIKE '%%,\"%v\" %%' OR sql LIKE '%%( %v %%' OR sql LIKE '%%, %v %%');\n", tableName, columnName, columnName, columnName, columnName)).Scan(&count)
+	scope.SqlDB().QueryRow(fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE tbl_name = '%v' AND (sql LIKE '%%(\"%v\" %%' OR sql LIKE '%%,\"%v\" %%' OR sql LIKE '%%( %v %%' OR sql LIKE '%%, %v %%');\n", tableName, columnName, columnName, columnName, columnName)).Scan(&count)
 	return count > 0
 }