fix: migrator run with nil schema

migrator/migrator.go

@@ -55,8 +55,6 @@ func (m Migrator) RunWithValue(value interface{}, fc func(*gorm.Statement) error
 
 	if table, ok := value.(string); ok {
 		stmt.Table = table
-		// set schema to avoid panic
-		stmt.Schema = &schema.Schema{}
 	} else if err := stmt.ParseWithSpecialTableName(value, stmt.Table); err != nil {
 		return err
 	}
@@ -347,7 +345,10 @@ func (m Migrator) RenameTable(oldName, newName interface{}) error {
 func (m Migrator) AddColumn(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
 		// avoid using the same name field
-		f := stmt.Schema.LookUpField(name)
+		var f *schema.Field
+		if stmt.Schema != nil {
+			f = stmt.Schema.LookUpField(name)
+		}
 		if f == nil {
 			return fmt.Errorf("failed to look up field with name: %s", name)
 		}
@@ -366,9 +367,11 @@ func (m Migrator) AddColumn(value interface{}, name string) error {
 // DropColumn drop value's `name` column
 func (m Migrator) DropColumn(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema != nil {
 			if field := stmt.Schema.LookUpField(name); field != nil {
 				name = field.DBName
 			}
+		}
 
 		return m.DB.Exec(
 			"ALTER TABLE ? DROP COLUMN ?", m.CurrentTable(stmt), clause.Column{Name: name},
@@ -379,13 +382,14 @@ func (m Migrator) DropColumn(value interface{}, name string) error {
 // AlterColumn alter value's `field` column' type based on schema definition
 func (m Migrator) AlterColumn(value interface{}, field string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema != nil {
 			if field := stmt.Schema.LookUpField(field); field != nil {
 				fileType := m.FullDataTypeOf(field)
 				return m.DB.Exec(
 					"ALTER TABLE ? ALTER COLUMN ? TYPE ?",
 					m.CurrentTable(stmt), clause.Column{Name: field.DBName}, fileType,
 				).Error
-
+			}
 		}
 		return fmt.Errorf("failed to look up field with name: %s", field)
 	})
@@ -397,9 +401,11 @@ func (m Migrator) HasColumn(value interface{}, field string) bool {
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
 		currentDatabase := m.DB.Migrator().CurrentDatabase()
 		name := field
+		if stmt.Schema != nil {
 			if field := stmt.Schema.LookUpField(field); field != nil {
 				name = field.DBName
 			}
+		}
 
 		return m.DB.Raw(
 			"SELECT count(*) FROM INFORMATION_SCHEMA.columns WHERE table_schema = ? AND table_name = ? AND column_name = ?",
@@ -413,6 +419,7 @@ func (m Migrator) HasColumn(value interface{}, field string) bool {
 // RenameColumn rename value's field name from oldName to newName
 func (m Migrator) RenameColumn(value interface{}, oldName, newName string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema != nil {
 			if field := stmt.Schema.LookUpField(oldName); field != nil {
 				oldName = field.DBName
 			}
@@ -420,6 +427,7 @@ func (m Migrator) RenameColumn(value interface{}, oldName, newName string) error
 			if field := stmt.Schema.LookUpField(newName); field != nil {
 				newName = field.DBName
 			}
+		}
 
 		return m.DB.Exec(
 			"ALTER TABLE ? RENAME COLUMN ? TO ?",
@@ -756,6 +764,7 @@ type BuildIndexOptionsInterface interface {
 // CreateIndex create index `name`
 func (m Migrator) CreateIndex(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema != nil {
 			if idx := stmt.Schema.LookIndex(name); idx != nil {
 				opts := m.DB.Migrator().(BuildIndexOptionsInterface).BuildIndexOptions(idx.Fields, stmt)
 				values := []interface{}{clause.Column{Name: idx.Name}, m.CurrentTable(stmt), opts}
@@ -780,6 +789,7 @@ func (m Migrator) CreateIndex(value interface{}, name string) error {
 
 				return m.DB.Exec(createIndexSQL, values...).Error
 			}
+		}
 
 		return fmt.Errorf("failed to create index with name %s", name)
 	})
@@ -788,9 +798,11 @@ func (m Migrator) CreateIndex(value interface{}, name string) error {
 // DropIndex drop index `name`
 func (m Migrator) DropIndex(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema != nil {
 			if idx := stmt.Schema.LookIndex(name); idx != nil {
 				name = idx.Name
 			}
+		}
 
 		return m.DB.Exec("DROP INDEX ? ON ?", clause.Column{Name: name}, m.CurrentTable(stmt)).Error
 	})
@@ -801,9 +813,11 @@ func (m Migrator) HasIndex(value interface{}, name string) bool {
 	var count int64
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
 		currentDatabase := m.DB.Migrator().CurrentDatabase()
+		if stmt.Schema != nil {
 			if idx := stmt.Schema.LookIndex(name); idx != nil {
 				name = idx.Name
 			}
+		}
 
 		return m.DB.Raw(
 			"SELECT count(*) FROM information_schema.statistics WHERE table_schema = ? AND table_name = ? AND index_name = ?",

tests/migrate_test.go

@@ -384,6 +384,22 @@ func TestMigrateIndexes(t *testing.T) {
 	if DB.Migrator().HasIndex(&IndexStruct{}, "idx_users_name_1") {
 		t.Fatalf("Should not find index for user's name after delete")
 	}
+
+	if err := DB.Migrator().CreateIndex(&IndexStruct{}, "Name"); err != nil {
+		t.Fatalf("Got error when tried to create index: %+v", err)
+	}
+
+	if err := DB.Migrator().RenameIndex("index_structs", "idx_index_structs_name", "idx_users_name_1"); err != nil {
+		t.Fatalf("no error should happen when rename index, but got %v", err)
+	}
+
+	if !DB.Migrator().HasIndex("index_structs", "idx_users_name_1") {
+		t.Fatalf("Should find index for user's name after rename")
+	}
+
+	if err := DB.Migrator().DropIndex("index_structs", "idx_users_name_1"); err != nil {
+		t.Fatalf("Failed to drop index for user's name, got err %v", err)
+	}
 }
 
 func TestTiDBMigrateColumns(t *testing.T) {