misc: postgres compose sql var

create_test.go

@@ -12,7 +12,7 @@ import (
 func TestCreate(t *testing.T) {
 	float := 35.03554004971999
 	now := time.Now()
-	user := User{Name: "CreateUser", Age: 18, Birthday: &now, UserNum: Num(111), PasswordHash: []byte{'f', 'a', 'k', '4'}, Latitude: float}
+	user := User{Name: "CreateUser", Age: 18, Birthday: &now, UserNum: Num(111), PasswordHash: []byte{0, 'f', 'a', 'k', '4'}, Latitude: float}
 
 	if !DB.NewRecord(user) || !DB.NewRecord(&user) {
 		t.Error("User should be new record before create")
@@ -29,7 +29,7 @@ func TestCreate(t *testing.T) {
 	var newUser User
 	DB.First(&newUser, user.Id)
 
-	if !reflect.DeepEqual(newUser.PasswordHash, []byte{'f', 'a', 'k', '4'}) {
+	if !reflect.DeepEqual(newUser.PasswordHash, []byte{0, 'f', 'a', 'k', '4'}) {
 		t.Errorf("User's PasswordHash should be saved ([]byte)")
 	}
 

dialect.go

@@ -16,6 +16,9 @@ type Dialect interface {
 	// SetDB set db for dialect
 	SetDB(db SQLCommon)
 
+	// StringifyVar return escape string of var
+	StringifyVar(value interface{}) (string, bool)
+
 	// BindVar return the placeholder for actual values in SQL statements, in many dbs it is "?", Postgres using $1
 	BindVar(i int) string
 	// Quote quotes field name to avoid SQL parsing exceptions by using a reserved word as a field name

dialect_common.go

@@ -30,6 +30,10 @@ func (s *commonDialect) SetDB(db SQLCommon) {
 	s.db = db
 }
 
+func (commonDialect) StringifyVar(value interface{}) (string, bool) {
+	return "", false
+}
+
 func (commonDialect) BindVar(i int) string {
 	return "$$$" // ?
 }

dialect_postgres.go

@@ -1,10 +1,14 @@
 package gorm
 
 import (
+	"database/sql/driver"
+	"encoding/hex"
 	"fmt"
 	"reflect"
 	"strings"
 	"time"
+
+	dPostgres "github.com/jinzhu/gorm/dialects/postgres"
 )
 
 type postgres struct {
@@ -20,6 +24,88 @@ func (postgres) GetName() string {
 	return "postgres"
 }
 
+func literal(s string) string {
+	p := ""
+
+	if strings.Contains(s, `\`) {
+		p = "E"
+	}
+
+	s = strings.Replace(s, `'`, `''`, -1)
+	s = strings.Replace(s, `\`, `\\`, -1)
+	return p + `'` + s + `'`
+}
+
+func isNil(value interface{}) (ret bool) {
+	ret = false
+	defer func() {
+		if e := recover(); e != nil {
+			// DO NOTHING
+		}
+	}()
+
+	if value == nil {
+		ret = true
+		return
+	}
+
+	if reflect.ValueOf(value).IsNil() {
+		ret = true
+		return
+	}
+
+	return
+}
+
+func (p postgres) StringifyVar(value interface{}) (ret string, ok bool) {
+	ok = true
+	if isNil(value) {
+		ret = "NULL"
+		return
+	}
+
+	if reflect.TypeOf(value).Kind() == reflect.Ptr {
+		ret, ok = p.StringifyVar(reflect.ValueOf(value).Elem().Interface())
+		return
+	}
+
+	switch value.(type) {
+	case string:
+		s := value.(string)
+		ret = literal(s)
+		return
+	case time.Time:
+		s := value.(time.Time)
+		ret = literal(s.Format(time.RFC3339Nano))
+		return
+	case dPostgres.Hstore:
+		s := value.(dPostgres.Hstore)
+		if v, err := s.Value(); err == nil {
+			ret = literal(string(v.([]byte)))
+			return
+		}
+	case []byte:
+		s := value.([]byte)
+		ret = "decode(" + literal(hex.EncodeToString(s)) + ", 'hex')"
+		return
+	}
+
+	if s, ok2 := value.(driver.Valuer); ok2 {
+		if v, err := s.Value(); err == nil {
+			ret, ok = p.StringifyVar(v)
+			return
+		}
+	}
+
+	if s, ok2 := value.(fmt.Stringer); ok2 {
+		ret = literal(s.String())
+		return
+	}
+
+	ret = fmt.Sprintf("%v", value)
+	return
+}
+
 func (postgres) BindVar(i int) string {
 	return fmt.Sprintf("$%v", i)
 }

dialects/mssql/mssql.go

@@ -49,6 +49,10 @@ func (s *mssql) SetDB(db gorm.SQLCommon) {
 	s.db = db
 }
 
+func (mssql) StringifyVar(value interface{}) (string, bool) {
+	return "", false
+}
+
 func (mssql) BindVar(i int) string {
 	return "$$$" // ?
 }

main_test.go

@@ -727,6 +727,7 @@ func TestHstore(t *testing.T) {
 		"bankAccountId": &bankAccountId,
 		"phoneNumber":   &phoneNumber,
 		"opinion":       &opinion,
+		"nil":           nil,
 	}
 	d := Details{Bulk: bulk}
 	DB.Save(&d)
@@ -738,8 +739,15 @@ func TestHstore(t *testing.T) {
 
 	for k := range bulk {
 		if r, ok := d2.Bulk[k]; ok {
-			if res, _ := bulk[k]; *res != *r {
+			res, _ := bulk[k]
-				t.Errorf("Details should be equal")
+			if res == nil || r == nil {
+				if res != r {
+					t.Errorf("Details should be equal")
+				}
+			} else {
+				if *res != *r {
+					t.Errorf("Details should be equal")
+				}
 			}
 		} else {
 			t.Errorf("Details should be existed")

scope.go

@@ -267,12 +267,17 @@ func (scope *Scope) AddToVars(value interface{}) string {
 		return exp
 	}
 
+	dialect := scope.Dialect()
+	if str, ok := dialect.StringifyVar(value); ok {
+		return str
+	}
+
 	scope.SQLVars = append(scope.SQLVars, value)
 
 	if skipBindVar {
 		return "?"
 	}
-	return scope.Dialect().BindVar(len(scope.SQLVars))
+	return dialect.BindVar(len(scope.SQLVars))
 }
 
 // SelectAttrs return selected attributes