diff --git a/dialect.go b/dialect.go
index 05375642..29486d5d 100644
--- a/dialect.go
+++ b/dialect.go
@@ -52,10 +52,7 @@ type Dialect interface {
 
 	IndexCheckSql(tableName, idxName string) (string, []interface{})
 	TableCheckSql(tableName string) (string, []interface{})
-	//ColumnCheckSql(tableName, colName string) (string, []interface{})
 
-	//IsTableExist(tableName string) (bool, error)
-	//IsIndexExist(tableName string, idx *Index) (bool, error)
 	IsColumnExist(tableName string, col *Column) (bool, error)
 
 	CreateTableSql(table *Table, tableName, storeEngine, charset string) string
@@ -176,10 +173,8 @@ func (db *Base) CreateIndexSql(tableName string, index *Index) string {
 	var idxName string
 	if index.Type == UniqueType {
 		unique = " UNIQUE"
-		idxName = fmt.Sprintf("UQE_%v_%v", tableName, index.Name)
-	} else {
-		idxName = fmt.Sprintf("IDX_%v_%v", tableName, index.Name)
 	}
+	idxName = index.XName(tableName)
 	return fmt.Sprintf("CREATE%s INDEX %v ON %v (%v);", unique,
 		quote(idxName), quote(tableName),
 		quote(strings.Join(index.Cols, quote(","))))
@@ -187,18 +182,13 @@ func (db *Base) CreateIndexSql(tableName string, index *Index) string {
 
 func (db *Base) DropIndexSql(tableName string, index *Index) string {
 	quote := db.dialect.Quote
-	//var unique string
-	var idxName string = index.Name
-	if !strings.HasPrefix(idxName, "UQE_") &&
-		!strings.HasPrefix(idxName, "IDX_") {
-		if index.Type == UniqueType {
-			idxName = fmt.Sprintf("UQE_%v_%v", tableName, index.Name)
-		} else {
-			idxName = fmt.Sprintf("IDX_%v_%v", tableName, index.Name)
-		}
+	var name string
+	if index.IsRegular {
+		name = index.XName(tableName)
+	} else {
+		name = index.Name
 	}
-	return fmt.Sprintf("DROP INDEX %v ON %s",
-		quote(idxName), quote(tableName))
+	return fmt.Sprintf("DROP INDEX %v ON %s", quote(name), quote(tableName))
 }
 
 func (db *Base) ModifyColumnSql(tableName string, col *Column) string {
diff --git a/index.go b/index.go
index e8f447d7..73b95175 100644
--- a/index.go
+++ b/index.go
@@ -1,7 +1,9 @@
 package core
 
 import (
+	"fmt"
 	"sort"
+	"strings"
 )
 
 const (
@@ -11,9 +13,21 @@ const (
 
 // database index
 type Index struct {
-	Name string
-	Type int
-	Cols []string
+	IsRegular bool
+	Name      string
+	Type      int
+	Cols      []string
+}
+
+func (index *Index) XName(tableName string) string {
+	if !strings.HasPrefix(index.Name, "UQE_") &&
+		!strings.HasPrefix(index.Name, "IDX_") {
+		if index.Type == UniqueType {
+			return fmt.Sprintf("UQE_%v_%v", tableName, index.Name)
+		}
+		return fmt.Sprintf("IDX_%v_%v", tableName, index.Name)
+	}
+	return index.Name
 }
 
 // add columns which will be composite index
@@ -24,6 +38,9 @@ func (index *Index) AddColumn(cols ...string) {
 }
 
 func (index *Index) Equal(dst *Index) bool {
+	if index.Type != dst.Type {
+		return false
+	}
 	if len(index.Cols) != len(dst.Cols) {
 		return false
 	}
@@ -40,5 +57,5 @@ func (index *Index) Equal(dst *Index) bool {
 
 // new an index
 func NewIndex(name string, indexType int) *Index {
-	return &Index{name, indexType, make([]string, 0)}
+	return &Index{true, name, indexType, make([]string, 0)}
 }