From 115789960a57e1909cf29c5fba5018e071a48965 Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Tue, 16 Feb 2016 22:48:26 +0800
Subject: [PATCH] Joins support parameters, close #673

---
 README.md        |  2 +-
 main.go          |  4 ++--
 main_test.go     | 14 ++++++++++----
 scope_private.go | 14 ++++++++++----
 search.go        |  6 +++---
 5 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index 0f195561..1c06820e 100644
--- a/README.md
+++ b/README.md
@@ -929,7 +929,7 @@ db.Table("users").Select("users.name, emails.email").Joins("left join emails on
 db.Joins("inner join emails on emails.user_id = users.id").Where("emails.email = ?", "x@example.org").Find(&user)
 
 // find all email addresses for a user
-db.Joins("left join users on users.id = emails.user_id").Where("users.name = ?", "jinzhu").Find(&emails)
+db.Joins("LEFT JOIN users ON users.id = emails.user_id AND users.name = ?", "jinzhu").Find(&emails)
 ```
 
 ## Transactions
diff --git a/main.go b/main.go
index 9581a216..b7f0d2aa 100644
--- a/main.go
+++ b/main.go
@@ -171,8 +171,8 @@ func (s *DB) Having(query string, values ...interface{}) *DB {
 	return s.clone().search.Having(query, values...).db
 }
 
-func (s *DB) Joins(query string) *DB {
-	return s.clone().search.Joins(query).db
+func (s *DB) Joins(query string, args ...interface{}) *DB {
+	return s.clone().search.Joins(query, args...).db
 }
 
 func (s *DB) Scopes(funcs ...func(*DB) *DB) *DB {
diff --git a/main_test.go b/main_test.go
index 97a3d84e..39189cd3 100644
--- a/main_test.go
+++ b/main_test.go
@@ -506,10 +506,16 @@ func TestJoins(t *testing.T) {
 	}
 	DB.Save(&user)
 
-	var result User
-	DB.Joins("left join emails on emails.user_id = users.id").Where("name = ?", "joins").First(&result)
-	if result.Name != "joins" || result.Id != user.Id {
-		t.Errorf("Should find all two emails with Join")
+	var users1 []User
+	DB.Joins("left join emails on emails.user_id = users.id").Where("name = ?", "joins").Find(&users1)
+	if len(users1) != 2 {
+		t.Errorf("should find two users using left join")
+	}
+
+	var users2 []User
+	DB.Joins("left join emails on emails.user_id = users.id AND emails.email = ?", "join1@example.com").Where("name = ?", "joins").First(&users2)
+	if len(users2) != 1 {
+		t.Errorf("should find one users using left join with conditions")
 	}
 }
 
diff --git a/scope_private.go b/scope_private.go
index 4ed2060c..6b34a4b3 100644
--- a/scope_private.go
+++ b/scope_private.go
@@ -234,7 +234,7 @@ var hasCountRegexp = regexp.MustCompile(`(?i)count\(.+\)`)
 
 func (scope *Scope) selectSql() string {
 	if len(scope.Search.selects) == 0 {
-		if scope.Search.joins != "" {
+		if len(scope.Search.joinConditions) > 0 {
 			return fmt.Sprintf("%v.*", scope.QuotedTableName())
 		}
 		return "*"
@@ -263,12 +263,11 @@ func (scope *Scope) groupSql() string {
 }
 
 func (scope *Scope) havingSql() string {
-	if scope.Search.havingConditions == nil {
+	if len(scope.Search.havingConditions) == 0 {
 		return ""
 	}
 
 	var andConditions []string
-
 	for _, clause := range scope.Search.havingConditions {
 		if sql := scope.buildWhereCondition(clause); sql != "" {
 			andConditions = append(andConditions, sql)
@@ -284,7 +283,14 @@ func (scope *Scope) havingSql() string {
 }
 
 func (scope *Scope) joinsSql() string {
-	return scope.Search.joins + " "
+	var joinConditions []string
+	for _, clause := range scope.Search.joinConditions {
+		if sql := scope.buildWhereCondition(clause); sql != "" {
+			joinConditions = append(joinConditions, strings.TrimSuffix(strings.TrimPrefix(sql, "("), ")"))
+		}
+	}
+
+	return strings.Join(joinConditions, " ") + " "
 }
 
 func (scope *Scope) prepareQuerySql() {
diff --git a/search.go b/search.go
index c6d070f0..4e31ae03 100644
--- a/search.go
+++ b/search.go
@@ -8,12 +8,12 @@ type search struct {
 	orConditions     []map[string]interface{}
 	notConditions    []map[string]interface{}
 	havingConditions []map[string]interface{}
+	joinConditions   []map[string]interface{}
 	initAttrs        []interface{}
 	assignAttrs      []interface{}
 	selects          map[string]interface{}
 	omits            []string
 	orders           []string
-	joins            string
 	preload          []searchPreload
 	offset           int
 	limit            int
@@ -102,8 +102,8 @@ func (s *search) Having(query string, values ...interface{}) *search {
 	return s
 }
 
-func (s *search) Joins(query string) *search {
-	s.joins = query
+func (s *search) Joins(query string, values ...interface{}) *search {
+	s.joinConditions = append(s.joinConditions, map[string]interface{}{"query": query, "args": values})
 	return s
 }