Merge pull request #282 from jnfeinstein/master

Add additional methods of specifying the 'select' portion of a query.

README.md

@@ -609,6 +609,12 @@ db.Where(User{Name: "jinzhu"}).Assign(User{Age: 30}).FirstOrCreate(&user)
 ```go
 db.Select("name, age").Find(&users)
 //// SELECT name, age FROM users;
+
+db.Select([]string{"name", "age"}).Find(&users)
+//// SELECT name, age FROM users;
+
+db.Table("users").Select("COALESCE(age,?)", 42).Rows()
+//// SELECT COALESCE(age,'42') FROM users;
 ```
 
 ## Order

main.go

@@ -125,8 +125,8 @@ func (s *DB) Order(value string, reorder ...bool) *DB {
 	return s.clone().search.order(value, reorder...).db
 }
 
-func (s *DB) Select(value interface{}) *DB {
+func (s *DB) Select(query interface{}, args ...interface{}) *DB {
-	return s.clone().search.selects(value).db
+	return s.clone().search.selects(query, args...).db
 }
 
 func (s *DB) Group(query string) *DB {

query_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/jinzhu/now"
 
+	"math/rand"
 	"testing"
 	"time"
 )
@@ -537,3 +538,25 @@ func TestSelectWithEscapedFieldName(t *testing.T) {
 		t.Errorf("Expected 3 name, but got: %d", len(names))
 	}
 }
+
+func TestSelectWithVariables(t *testing.T) {
+	DB.Save(&User{Name: "jinzhu"})
+
+	randomNum := rand.Intn(1000000000)
+	rows, _ := DB.Table("users").Select("? as fake", randomNum).Where("fake = ?", randomNum).Rows()
+
+	if !rows.Next() {
+		t.Errorf("Should have returned at least one row")
+	}
+}
+
+func TestSelectWithArrayInput(t *testing.T) {
+	DB.Save(&User{Name: "jinzhu", Age: 42})
+
+	var user User
+	DB.Select([]string{"name", "age"}).Where("age = 42 AND name = 'jinzhu'").First(&user)
+
+	if user.Name != "jinzhu" || user.Age != 42 {
+		t.Errorf("Should have selected both age and name")
+	}
+}

scope_private.go

@@ -129,6 +129,34 @@ func (scope *Scope) buildNotCondition(clause map[string]interface{}) (str string
 	return
 }
 
+func (scope *Scope) buildSelectQuery(clause map[string]interface{}) (str string) {
+	switch value := clause["query"].(type) {
+	case string:
+		str = value
+	case []string:
+		str = strings.Join(value, ", ")
+	}
+
+	args := clause["args"].([]interface{})
+	for _, arg := range args {
+		switch reflect.TypeOf(arg).Kind() {
+		case reflect.Slice:
+			values := reflect.ValueOf(arg)
+			var tempMarks []string
+			for i := 0; i < values.Len(); i++ {
+				tempMarks = append(tempMarks, scope.AddToVars(values.Index(i).Interface()))
+			}
+			str = strings.Replace(str, "?", strings.Join(tempMarks, ","), 1)
+		default:
+			if valuer, ok := interface{}(arg).(driver.Valuer); ok {
+				arg, _ = valuer.Value()
+			}
+			str = strings.Replace(str, "?", scope.AddToVars(arg), 1)
+		}
+	}
+	return
+}
+
 func (scope *Scope) where(where ...interface{}) {
 	if len(where) > 0 {
 		scope.Search = scope.Search.clone().where(where[0], where[1:]...)
@@ -180,11 +208,18 @@ func (scope *Scope) whereSql() (sql string) {
 }
 
 func (s *Scope) selectSql() string {
-	if len(s.Search.Select) == 0 {
+	if len(s.Search.Selects) == 0 {
 		return "*"
-	} else {
-		return s.Search.Select
 	}
+
+	var selectQueries []string
+
+	for _, clause := range s.Search.Selects {
+		selectQueries = append(selectQueries, s.buildSelectQuery(clause))
+	}
+
+	return strings.Join(selectQueries, ", ")
+
 }
 
 func (s *Scope) orderSql() string {

search.go

@@ -12,7 +12,7 @@ type search struct {
 	HavingCondition map[string]interface{}
 	Orders          []string
 	Joins           string
-	Select          string
+	Selects         []map[string]interface{}
 	Offset          string
 	Limit           string
 	Group           string
@@ -30,7 +30,7 @@ func (s *search) clone() *search {
 		AssignAttrs:     s.AssignAttrs,
 		HavingCondition: s.HavingCondition,
 		Orders:          s.Orders,
-		Select:          s.Select,
+		Selects:         s.Selects,
 		Offset:          s.Offset,
 		Limit:           s.Limit,
 		Unscope:         s.Unscope,
@@ -75,8 +75,8 @@ func (s *search) order(value string, reorder ...bool) *search {
 	return s
 }
 
-func (s *search) selects(value interface{}) *search {
+func (s *search) selects(query interface{}, args ...interface{}) *search {
-	s.Select = s.getInterfaceAsSql(value)
+	s.Selects = append(s.Selects, map[string]interface{}{"query": query, "args": args})
 	return s
 }
 

search_test.go

@@ -24,7 +24,7 @@ func TestCloneSearch(t *testing.T) {
 		t.Errorf("InitAttrs should be copied")
 	}
 
-	if reflect.DeepEqual(s.Select, s1.Select) {
+	if reflect.DeepEqual(s.Selects, s1.Selects) {
 		t.Errorf("selectStr should be copied")
 	}
 }