diff --git a/callbacks/update.go b/callbacks/update.go
index 623d64fe..cfa8c86b 100644
--- a/callbacks/update.go
+++ b/callbacks/update.go
@@ -3,7 +3,6 @@ package callbacks
 import (
 	"reflect"
 	"sort"
-	"time"
 
 	"github.com/jinzhu/gorm"
 	"github.com/jinzhu/gorm/clause"
@@ -152,7 +151,7 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 		if !stmt.DisableUpdateTime {
 			for _, field := range stmt.Schema.FieldsByDBName {
 				if field.AutoUpdateTime > 0 && value[field.Name] == nil && value[field.DBName] == nil {
-					now := time.Now()
+					now := stmt.DB.NowFunc()
 					set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now})
 					assignValue(field, now)
 				}
@@ -168,7 +167,7 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 						value, isZero := field.ValueOf(stmt.ReflectValue)
 						if !stmt.DisableUpdateTime {
 							if field.AutoUpdateTime > 0 {
-								value = time.Now()
+								value = stmt.DB.NowFunc()
 								isZero = false
 							}
 						}
diff --git a/dialects/mssql/migrator.go b/dialects/mssql/migrator.go
index 4707a637..d1abd0e9 100644
--- a/dialects/mssql/migrator.go
+++ b/dialects/mssql/migrator.go
@@ -1,7 +1,10 @@
 package mssql
 
 import (
+	"fmt"
+
 	"github.com/jinzhu/gorm"
+	"github.com/jinzhu/gorm/clause"
 	"github.com/jinzhu/gorm/migrator"
 )
 
@@ -20,6 +23,24 @@ func (m Migrator) HasTable(value interface{}) bool {
 	return count > 0
 }
 
+func (m Migrator) HasColumn(value interface{}, field string) bool {
+	var count int64
+	m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		currentDatabase := m.DB.Migrator().CurrentDatabase()
+		name := field
+		if field := stmt.Schema.LookUpField(field); field != nil {
+			name = field.DBName
+		}
+
+		return m.DB.Raw(
+			"SELECT count(*) FROM INFORMATION_SCHEMA.columns WHERE table_catalog = ? AND table_name = ? AND column_name = ?",
+			currentDatabase, stmt.Table, name,
+		).Row().Scan(&count)
+	})
+
+	return count > 0
+}
+
 func (m Migrator) HasIndex(value interface{}, name string) bool {
 	var count int
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
@@ -35,6 +56,16 @@ func (m Migrator) HasIndex(value interface{}, name string) bool {
 	return count > 0
 }
 
+func (m Migrator) RenameIndex(value interface{}, oldName, newName string) error {
+	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+
+		return m.DB.Exec(
+			"sp_rename @objname = ?, @newname = ?, @objtype = 'INDEX';",
+			fmt.Sprintf("%s.%s", stmt.Table, oldName), clause.Column{Name: newName},
+		).Error
+	})
+}
+
 func (m Migrator) HasConstraint(value interface{}, name string) bool {
 	var count int64
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
diff --git a/dialects/mssql/mssql.go b/dialects/mssql/mssql.go
index 8e309faf..3828c546 100644
--- a/dialects/mssql/mssql.go
+++ b/dialects/mssql/mssql.go
@@ -2,7 +2,6 @@ package mssql
 
 import (
 	"database/sql"
-	"database/sql/driver"
 	"fmt"
 	"regexp"
 	"strconv"
@@ -81,15 +80,6 @@ func (dialector Dialector) QuoteTo(writer clause.Writer, str string) {
 var numericPlaceholder = regexp.MustCompile("@p(\\d+)")
 
 func (dialector Dialector) Explain(sql string, vars ...interface{}) string {
-	for idx, v := range vars {
-		if valuer, ok := v.(driver.Valuer); ok {
-			v, _ = valuer.Value()
-		}
-
-		if v, ok := v.(bool); ok {
-			vars[idx] = strconv.FormatBool(v)
-		}
-	}
 	return logger.ExplainSQL(sql, numericPlaceholder, `'`, vars...)
 }
 
diff --git a/tests/tests_all.sh b/tests/tests_all.sh
index 9435b2b1..243af787 100755
--- a/tests/tests_all.sh
+++ b/tests/tests_all.sh
@@ -11,9 +11,9 @@ for dialect in "${dialects[@]}" ; do
 
     if [ "$GORM_VERBOSE" = "" ]
     then
-      DEBUG=false GORM_DIALECT=${dialect} go test -race ./...
+      DEBUG=false GORM_DIALECT=${dialect} go test -race -count=1 ./...
     else
-      DEBUG=false GORM_DIALECT=${dialect} go test -race -v ./...
+      DEBUG=false GORM_DIALECT=${dialect} go test -race -count=1 -v ./...
     fi
   fi
 done