diff --git a/common_dialect.go b/common_dialect.go
index e1a54c29..d8910dcd 100644
--- a/common_dialect.go
+++ b/common_dialect.go
@@ -86,26 +86,16 @@ func (s *commonDialect) databaseName(scope *Scope) string {
 
 func (s *commonDialect) 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_schema = %v",
-		newScope.AddToVars(tableName),
-		newScope.AddToVars(s.databaseName(scope))))
-	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	scope.NewDB().Raw("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = ? AND table_schema = ?", tableName, s.databaseName(scope)).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *commonDialect) HasColumn(scope *Scope, tableName string, columnName string) bool {
 	var count int
-	newScope := scope.New(nil)
-	newScope.Raw(fmt.Sprintf("SELECT count(*) FROM information_schema.columns WHERE table_schema = %v AND table_name = %v AND column_name = %v",
-		newScope.AddToVars(s.databaseName(scope)),
-		newScope.AddToVars(tableName),
-		newScope.AddToVars(columnName),
-	))
-	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	scope.NewDB().Raw("SELECT count(*) FROM information_schema.columns WHERE table_schema = ? AND table_name = ? AND column_name = ?", s.databaseName(scope), tableName, columnName).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *commonDialect) RemoveIndex(scope *Scope, indexName string) {
-	scope.Raw(fmt.Sprintf("DROP INDEX %v ON %v", indexName, scope.QuotedTableName())).Exec()
+	scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v ON %v", indexName, scope.QuotedTableName()))
 }
diff --git a/main_test.go b/main_test.go
index 1fa3b248..6ffbbf8d 100644
--- a/main_test.go
+++ b/main_test.go
@@ -35,7 +35,7 @@ func init() {
 		DB, err = gorm.Open("mysql", "gorm:gorm@/gorm?charset=utf8&parseTime=True")
 	case "postgres":
 		fmt.Println("testing postgres...")
-		DB, err = gorm.Open("postgres", "user=gorm DB.ame=gorm sslmode=disable")
+		DB, err = gorm.Open("postgres", "user=gorm DB.name=gorm sslmode=disable")
 	case "mssql":
 		fmt.Println("testing mssql...")
 		DB, err = gorm.Open("mssql", "server=SERVER_HERE;database=rogue;user id=USER_HERE;password=PW_HERE;port=1433")
diff --git a/migration_test.go b/migration_test.go
index 1a7ae6f2..0a2f0852 100644
--- a/migration_test.go
+++ b/migration_test.go
@@ -7,7 +7,7 @@ import (
 )
 
 func runMigration() {
-	if err := DB.DropTable(&User{}).Error; err != nil {
+	if err := DB.DropTableIfExists(&User{}).Error; err != nil {
 		fmt.Printf("Got error when try to delete table users, %+v\n", err)
 	}
 
diff --git a/mssql.go b/mssql.go
index 30f9b824..720dc615 100644
--- a/mssql.go
+++ b/mssql.go
@@ -88,26 +88,16 @@ func (s *mssql) databaseName(scope *Scope) string {
 
 func (s *mssql) 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_catalog = %v",
-		newScope.AddToVars(tableName),
-		newScope.AddToVars(s.databaseName(scope))))
-	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	scope.NewDB().Raw("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = ? AND table_catalog = ?", tableName, s.databaseName(scope)).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *mssql) HasColumn(scope *Scope, tableName string, columnName string) bool {
 	var count int
-	newScope := scope.New(nil)
-	newScope.Raw(fmt.Sprintf("SELECT count(*) FROM information_schema.columns WHERE TABLE_CATALOG = %v AND table_name = %v AND column_name = %v",
-		newScope.AddToVars(s.databaseName(scope)),
-		newScope.AddToVars(tableName),
-		newScope.AddToVars(columnName),
-	))
-	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	scope.NewDB().Raw("SELECT count(*) FROM information_schema.columns WHERE table_catalog = ? AND table_name = ? AND column_name = ?", s.databaseName(scope), tableName, columnName).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *mssql) RemoveIndex(scope *Scope, indexName string) {
-	scope.Raw(fmt.Sprintf("DROP INDEX %v ON %v", indexName, scope.QuotedTableName())).Exec()
+	scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v ON %v", indexName, scope.QuotedTableName()))
 }
diff --git a/mysql.go b/mysql.go
index ec575336..3c077b4b 100644
--- a/mysql.go
+++ b/mysql.go
@@ -86,26 +86,16 @@ func (s *mysql) databaseName(scope *Scope) string {
 
 func (s *mysql) 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_schema = %v",
-		newScope.AddToVars(tableName),
-		newScope.AddToVars(s.databaseName(scope))))
-	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	scope.NewDB().Raw("SELECT count(*) FROM INFORMATION_SCHEMA.tables where table_name = ? AND table_schema = ?", tableName, s.databaseName(scope)).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *mysql) HasColumn(scope *Scope, tableName string, columnName string) bool {
 	var count int
-	newScope := scope.New(nil)
-	newScope.Raw(fmt.Sprintf("SELECT count(*) FROM information_schema.columns WHERE table_schema = %v AND table_name = %v AND column_name = %v",
-		newScope.AddToVars(s.databaseName(scope)),
-		newScope.AddToVars(tableName),
-		newScope.AddToVars(columnName),
-	))
-	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	scope.NewDB().Raw("SELECT count(*) FROM information_schema.columns WHERE table_schema = ? AND table_name = ? AND column_name = ?", s.databaseName(scope), tableName, columnName).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *mysql) RemoveIndex(scope *Scope, indexName string) {
-	scope.Raw(fmt.Sprintf("DROP INDEX %v ON %v", indexName, scope.QuotedTableName())).Exec()
+	scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v ON %v", indexName, scope.QuotedTableName()))
 }
diff --git a/postgres.go b/postgres.go
index 1ffbe4aa..994ed9b8 100644
--- a/postgres.go
+++ b/postgres.go
@@ -81,25 +81,18 @@ func (s *postgres) Quote(key string) string {
 
 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.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	scope.NewDB().Raw("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = ? AND table_type = 'BASE TABLE'", tableName).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *postgres) HasColumn(scope *Scope, tableName string, columnName string) bool {
 	var count int
-	newScope := scope.New(nil)
-	newScope.Raw(fmt.Sprintf("SELECT count(*) FROM information_schema.columns WHERE table_name = %v AND column_name = %v",
-		newScope.AddToVars(tableName),
-		newScope.AddToVars(columnName),
-	))
-	newScope.SqlDB().QueryRow(newScope.Sql, newScope.SqlVars...).Scan(&count)
+	scope.NewDB().Raw("SELECT count(*) FROM information_schema.columns WHERE table_name = ? AND column_name = ?", tableName, columnName).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *postgres) RemoveIndex(scope *Scope, indexName string) {
-	scope.Raw(fmt.Sprintf("DROP INDEX %v", s.Quote(indexName))).Exec()
+	scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v", indexName))
 }
 
 var hstoreType = reflect.TypeOf(Hstore{})
diff --git a/scope_private.go b/scope_private.go
index cb5c0f5e..433e364a 100644
--- a/scope_private.go
+++ b/scope_private.go
@@ -471,7 +471,9 @@ func (scope *Scope) dropTable() *Scope {
 }
 
 func (scope *Scope) dropTableIfExists() *Scope {
-	scope.Raw(fmt.Sprintf("DROP TABLE IF EXISTS %v", scope.QuotedTableName())).Exec()
+	if scope.Dialect().HasTable(scope, scope.TableName()) {
+		scope.dropTable()
+	}
 	return scope
 }
 
diff --git a/sqlite3.go b/sqlite3.go
index 7eb071d0..2ff10790 100644
--- a/sqlite3.go
+++ b/sqlite3.go
@@ -70,16 +70,16 @@ func (s *sqlite3) Quote(key string) string {
 
 func (s *sqlite3) HasTable(scope *Scope, tableName string) bool {
 	var count int
-	scope.SqlDB().QueryRow(fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE type='table' AND name='%v';", tableName)).Scan(&count)
+	scope.NewDB().Raw("SELECT count(*) FROM sqlite_master WHERE type='table' AND name=?", tableName).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *sqlite3) HasColumn(scope *Scope, tableName string, columnName string) bool {
 	var count int
-	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)
+	scope.NewDB().Raw(fmt.Sprintf("SELECT count(*) FROM sqlite_master WHERE tbl_name = ? AND (sql LIKE '%%(\"%v\" %%' OR sql LIKE '%%,\"%v\" %%' OR sql LIKE '%%( %v %%' OR sql LIKE '%%, %v %%');\n", columnName, columnName, columnName, columnName), tableName).Row().Scan(&count)
 	return count > 0
 }
 
 func (s *sqlite3) RemoveIndex(scope *Scope, indexName string) {
-	scope.Raw(fmt.Sprintf("DROP INDEX %v", indexName)).Exec()
+	scope.NewDB().Exec(fmt.Sprintf("DROP INDEX %v", indexName))
 }