From 4019c14651716e3c5a85ed44986a4b09bd3c0d52 Mon Sep 17 00:00:00 2001
From: Dmitry Yu Okunev <dyokunev@ut.mephi.ru>
Date: Fri, 22 May 2015 22:02:53 +0300
Subject: [PATCH] Added support of field gorm options drop_primary_keys and
 drop_unique_index

---
 README.md        |  4 ++--
 model_struct.go  | 16 ++++++++++++++--
 scope_private.go | 12 +++++++-----
 3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index 78e6e458..bf69a204 100644
--- a/README.md
+++ b/README.md
@@ -1177,8 +1177,8 @@ db.Where("email = ?", "x@example.org").Attrs(User{RegisteredIp: "111.111.111.111
 ```go
 type Delta struct {
 	Id       int;
-	Was      interface{} `gorm:"embedded:prefixed"`;
-	Became   interface{} `gorm:"embedded:prefixed"`;
+	Was      interface{} `gorm:"embedded:prefixed;drop_primary_keys;drop_unique_index"`;
+	Became   interface{} `gorm:"embedded:prefixed;drop_primary_keys;drop_unique_index"`;
 }
 
 type Login struct {
diff --git a/model_struct.go b/model_struct.go
index 0a1631a9..39ca525c 100644
--- a/model_struct.go
+++ b/model_struct.go
@@ -34,6 +34,8 @@ type StructField struct {
 	Tag             reflect.StructTag
 	Struct          reflect.StructField
 	IsForeignKey    bool
+	IgnoreUniqueIndex bool
+	IgnorePrimaryKey bool
 	Relationship    *Relationship
 	Value		reflect.Value
 }
@@ -307,7 +309,14 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 								}
 								toField.Names  = append([]string{fieldStruct.Name}, toField.Names...)
 								modelStruct.StructFields = append(modelStruct.StructFields, toField)
-								if toField.IsPrimaryKey {
+								if _, ok := gormSettings["DROP_UNIQUE_INDEX"]; ok {
+									toField.IgnoreUniqueIndex = true
+								}
+								if _, ok := gormSettings["DROP_PRIMARY_KEYS"]; ok {
+									toField.IgnorePrimaryKey  = true
+								}
+
+								if toField.IsPrimaryKey && !toField.IgnorePrimaryKey {
 									modelStruct.PrimaryFields = append(modelStruct.PrimaryFields, toField)
 								}
 							}
@@ -381,7 +390,10 @@ func (scope *Scope) generateSqlTag(field *StructField) string {
 		sqlType = value
 	}
 
-	additionalType := sqlSettings["NOT NULL"] + " " + sqlSettings["UNIQUE"]
+	additionalType := sqlSettings["NOT NULL"]
+	if !field.IgnoreUniqueIndex {
+		additionalType = " " + sqlSettings["UNIQUE"]
+	}
 	if value, ok := sqlSettings["DEFAULT"]; ok {
 		additionalType = additionalType + " DEFAULT " + value
 	}
diff --git a/scope_private.go b/scope_private.go
index 4ecefe3a..016244c9 100644
--- a/scope_private.go
+++ b/scope_private.go
@@ -474,7 +474,7 @@ func (scope *Scope) createTable() *Scope {
 			tags = append(tags, scope.Quote(field.DBName)+" "+sqlTag)
 		}
 
-		if field.IsPrimaryKey {
+		if field.IsPrimaryKey && !field.IgnorePrimaryKey {
 			primaryKeys = append(primaryKeys, field.DBName)
 		}
 		scope.createJoinTable(field)
@@ -572,11 +572,13 @@ func (scope *Scope) autoIndex() *Scope {
 			indexes[name] = append(indexes[name], field.DBName)
 		}
 
-		if name, ok := sqlSettings["UNIQUE_INDEX"]; ok {
-			if name == "UNIQUE_INDEX" {
-				name = fmt.Sprintf("uix_%v_%v", scope.TableName(), field.DBName)
+		if field.IgnoreUniqueIndex {
+			if name, ok := sqlSettings["UNIQUE_INDEX"]; ok {
+				if name == "UNIQUE_INDEX" {
+					name = fmt.Sprintf("uix_%v_%v", scope.TableName(), field.DBName)
+				}
+				uniqueIndexes[name] = append(uniqueIndexes[name], field.DBName)
 			}
-			uniqueIndexes[name] = append(uniqueIndexes[name], field.DBName)
 		}
 	}