From d1dc0ccbef7a6c737e9f65f24d0f21e730f1b4d3 Mon Sep 17 00:00:00 2001
From: Vladimir Garvardt <vgarvardt@gmail.com>
Date: Sun, 1 Jun 2014 02:35:56 +0400
Subject: [PATCH] AddUniqueIndex

---
 README.md        | 8 +++++++-
 main.go          | 7 ++++++-
 main_test.go     | 8 ++++++++
 scope_private.go | 9 +++++++--
 4 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index cecff94d..b729f92b 100644
--- a/README.md
+++ b/README.md
@@ -930,7 +930,13 @@ db.Table("users").Select("users.name, emails.email").Joins("left join emails on
 db.Model(User{}).AddIndex("idx_user_name", "name")
 
 // multiple column index
-db.Model(User{}).AddIndex("idx_user_name", "name", "age")
+db.Model(User{}).AddIndex("idx_user_name_age", "name", "age")
+
+// single column unique index
+db.Model(User{}).AddUniqueIndex("idx_user_name", "name")
+
+// multiple column unique index
+db.Model(User{}).AddUniqueIndex("idx_user_name_age", "name", "age")
 ```
 
 ## Run Raw SQL
diff --git a/main.go b/main.go
index 1c99150d..d655855c 100644
--- a/main.go
+++ b/main.go
@@ -315,7 +315,12 @@ func (s *DB) DropColumn(column string) *DB {
 }
 
 func (s *DB) AddIndex(indexName string, column ...string) *DB {
-	s.clone().NewScope(s.Value).addIndex(indexName, column...)
+	s.clone().NewScope(s.Value).addIndex(false, indexName, column...)
+	return s
+}
+
+func (s *DB) AddUniqueIndex(indexName string, column ...string) *DB {
+	s.clone().NewScope(s.Value).addIndex(true, indexName, column...)
 	return s
 }
 
diff --git a/main_test.go b/main_test.go
index 00796db9..78e79f23 100644
--- a/main_test.go
+++ b/main_test.go
@@ -2026,7 +2026,15 @@ func TestIndices(t *testing.T) {
 	if err := db.Model(&UserCompany{}).RemoveIndex("idx_user_company_user").Error; err != nil {
 		t.Errorf("Got error when tried to remove index: %+v", err)
 	}
+
 	if err := db.Model(&UserCompany{}).AddIndex("idx_user_company_user_company", "user_id", "company_id").Error; err != nil {
 		t.Errorf("Got error when tried to create index: %+v", err)
 	}
+	if err := db.Model(&UserCompany{}).RemoveIndex("idx_user_company_user_company").Error; err != nil {
+		t.Errorf("Got error when tried to remove index: %+v", err)
+	}
+
+	if err := db.Model(&UserCompany{}).AddUniqueIndex("idx_user_company_user_company", "user_id", "company_id").Error; err != nil {
+		t.Errorf("Got error when tried to create index: %+v", err)
+	}
 }
diff --git a/scope_private.go b/scope_private.go
index 8bfbf437..49c43d43 100644
--- a/scope_private.go
+++ b/scope_private.go
@@ -431,13 +431,18 @@ func (scope *Scope) dropColumn(column string) {
 	scope.Raw(fmt.Sprintf("ALTER TABLE %v DROP COLUMN %v", scope.Quote(scope.TableName()), scope.Quote(column))).Exec()
 }
 
-func (scope *Scope) addIndex(indexName string, column ...string) {
+func (scope *Scope) addIndex(unique bool, indexName string, column ...string) {
 	var columns []string
 	for _, name := range column {
 		columns = append(columns, scope.Quote(name))
 	}
 
-	scope.Raw(fmt.Sprintf("CREATE INDEX %v ON %v(%v);", indexName, scope.Quote(scope.TableName()), strings.Join(columns, ", "))).Exec()
+	sqlCreate := "CREATE INDEX"
+	if unique {
+		sqlCreate = "CREATE UNIQUE INDEX"
+	}
+
+	scope.Raw(fmt.Sprintf("%s %v ON %v(%v);", sqlCreate, indexName, scope.Quote(scope.TableName()), strings.Join(columns, ", "))).Exec()
 }
 
 func (scope *Scope) removeIndex(indexName string) {