From 133176c3fb17787899318781be945ee82c685a71 Mon Sep 17 00:00:00 2001
From: Thomas Boerger <tboerger@suse.de>
Date: Mon, 21 Mar 2016 15:16:04 +0100
Subject: [PATCH] Added separate function to generate primary keys

---
 dialect.go              |  2 ++
 dialect_common.go       |  4 ++++
 dialects/mssql/mssql.go |  4 ++++
 scope.go                | 15 +++++++++++++--
 4 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/dialect.go b/dialect.go
index 6c9405da..1c563083 100644
--- a/dialect.go
+++ b/dialect.go
@@ -20,6 +20,8 @@ type Dialect interface {
 	BindVar(i int) string
 	// Quote quotes field name to avoid SQL parsing exceptions by using a reserved word as a field name
 	Quote(key string) string
+	// PrimaryKeys used to define the primary keys of a table
+	PrimaryKeys(keys []string) string
 	// DataTypeOf return data's sql type
 	DataTypeOf(field *StructField) string
 
diff --git a/dialect_common.go b/dialect_common.go
index f009271b..72a6dd65 100644
--- a/dialect_common.go
+++ b/dialect_common.go
@@ -32,6 +32,10 @@ func (commonDialect) Quote(key string) string {
 	return fmt.Sprintf(`"%s"`, key)
 }
 
+func (commonDialect) PrimaryKeys(keys []string) string {
+	return fmt.Sprintf("PRIMARY KEY (%v)", strings.Join(keys, ","))
+}
+
 func (commonDialect) DataTypeOf(field *StructField) string {
 	var dataValue, sqlType, size, additionalType = ParseFieldStructForDialect(field)
 
diff --git a/dialects/mssql/mssql.go b/dialects/mssql/mssql.go
index 5b994f9d..e2b822d8 100644
--- a/dialects/mssql/mssql.go
+++ b/dialects/mssql/mssql.go
@@ -42,6 +42,10 @@ func (mssql) Quote(key string) string {
 	return fmt.Sprintf(`"%s"`, key)
 }
 
+func (mssql) PrimaryKeys(keys []string) string {
+	return fmt.Sprintf("PRIMARY KEY (%v)", strings.Join(keys, ","))
+}
+
 func (mssql) DataTypeOf(field *gorm.StructField) string {
 	var dataValue, sqlType, size, additionalType = gorm.ParseFieldStructForDialect(field)
 
diff --git a/scope.go b/scope.go
index da5f7ff3..0ed70d94 100644
--- a/scope.go
+++ b/scope.go
@@ -80,6 +80,17 @@ func (scope *Scope) Quote(str string) string {
 	return scope.Dialect().Quote(str)
 }
 
+// PrimaryKeys used to define the primary keys of a table
+func (scope *Scope) PrimaryKeys(keys []string) string {
+	res := scope.Dialect().PrimaryKeys(keys)
+
+	if res != "" {
+		return fmt.Sprintf(", %v", res)
+	}
+
+	return ""
+}
+
 // Err add error to Scope
 func (scope *Scope) Err(err error) error {
 	if err != nil {
@@ -1027,7 +1038,7 @@ func (scope *Scope) createJoinTable(field *StructField) {
 				}
 			}
 
-			scope.Err(scope.NewDB().Exec(fmt.Sprintf("CREATE TABLE %v (%v, PRIMARY KEY (%v)) %s", scope.Quote(joinTable), strings.Join(sqlTypes, ","), strings.Join(primaryKeys, ","), scope.getTableOptions())).Error)
+			scope.Err(scope.NewDB().Exec(fmt.Sprintf("CREATE TABLE %v (%v %v) %s", scope.Quote(joinTable), strings.Join(sqlTypes, ","), scope.PrimaryKeys(primaryKeys), scope.getTableOptions())).Error)
 		}
 		scope.NewDB().Table(joinTable).AutoMigrate(joinTableHandler)
 	}
@@ -1059,7 +1070,7 @@ func (scope *Scope) createTable() *Scope {
 
 	var primaryKeyStr string
 	if len(primaryKeys) > 0 && !primaryKeyInColumnType {
-		primaryKeyStr = fmt.Sprintf(", PRIMARY KEY (%v)", strings.Join(primaryKeys, ","))
+		primaryKeyStr = scope.PrimaryKeys(primaryKeys)
 	}
 
 	scope.Raw(fmt.Sprintf("CREATE TABLE %v (%v %v) %s", scope.QuotedTableName(), strings.Join(tags, ","), primaryKeyStr, scope.getTableOptions())).Exec()