From 9943db2f00a5e41540c64f88582c4277916d4848 Mon Sep 17 00:00:00 2001
From: Lunny Xiao <xiaolunwen@gmail.com>
Date: Mon, 19 Aug 2019 23:08:57 +0800
Subject: [PATCH 1/2] return error when find with no primary key selected

---
 error.go             | 19 +++++++++++++++++++
 session_find.go      | 15 +++++++++++++--
 session_find_test.go | 21 ++++++++++++++++++++-
 3 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/error.go b/error.go
index a67527acd..51e2d3ee8 100644
--- a/error.go
+++ b/error.go
@@ -28,6 +28,10 @@ var (
 	ErrConditionType = errors.New("Unsupported condition type")
 	// ErrUnSupportedSQLType parameter of SQL is not supported
 	ErrUnSupportedSQLType = errors.New("unsupported sql type")
+	// ErrNoPrimaryKey represents an error lack of primary key
+	ErrNoPrimaryKey = errors.New("Current table has no necessary primary key")
+	// ErrMapKeyIsNotValid represents an error map key is not valid
+	ErrMapKeyIsNotValid = errors.New("Map key type must be a slice because the table have serval primary keys")
 )
 
 // ErrFieldIsNotExist columns does not exist
@@ -49,3 +53,18 @@ type ErrFieldIsNotValid struct {
 func (e ErrFieldIsNotValid) Error() string {
 	return fmt.Sprintf("field %s is not valid on table %s", e.FieldName, e.TableName)
 }
+
+// ErrPrimaryKeyNoSelected represents an error primary key not selected
+type ErrPrimaryKeyNoSelected struct {
+	PrimaryKey string
+}
+
+func (e ErrPrimaryKeyNoSelected) Error() string {
+	return fmt.Sprintf("primary key %s is not selected", e.PrimaryKey)
+}
+
+// IsErrPrimaryKeyNoSelected returns true is err is  ErrPrimaryKeyNoSelected
+func IsErrPrimaryKeyNoSelected(err error) bool {
+	_, ok := err.(ErrPrimaryKeyNoSelected)
+	return ok
+}
diff --git a/session_find.go b/session_find.go
index 6b8aa469d..43c6d892f 100644
--- a/session_find.go
+++ b/session_find.go
@@ -250,10 +250,21 @@ func (session *Session) noCacheFind(table *core.Table, containerValue reflect.Va
 	} else {
 		keyType := containerValue.Type().Key()
 		if len(table.PrimaryKeys) == 0 {
-			return errors.New("don't support multiple primary key's map has non-slice key type")
+			return ErrNoPrimaryKey
 		}
 		if len(table.PrimaryKeys) > 1 && keyType.Kind() != reflect.Slice {
-			return errors.New("don't support multiple primary key's map has non-slice key type")
+			return ErrMapKeyIsNotValid
+		}
+
+		var found bool
+		for _, field := range fields {
+			if strings.EqualFold(field, table.PrimaryKeys[0]) {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return ErrPrimaryKeyNoSelected{table.PrimaryKeys[0]}
 		}
 
 		containerValueSetFunc = func(newValue *reflect.Value, pk core.PK) error {
diff --git a/session_find_test.go b/session_find_test.go
index f805f06e0..3be6a51b9 100644
--- a/session_find_test.go
+++ b/session_find_test.go
@@ -10,8 +10,8 @@ import (
 	"testing"
 	"time"
 
-	"xorm.io/core"
 	"github.com/stretchr/testify/assert"
+	"xorm.io/core"
 )
 
 func TestJoinLimit(t *testing.T) {
@@ -801,3 +801,22 @@ func TestFindJoin(t *testing.T) {
 		Where("scene_item.type=?", 3).Or("device_user_privrels.user_id=?", 339).Find(&scenes)
 	assert.NoError(t, err)
 }
+
+func TestFindMapCols(t *testing.T) {
+	type FindMapCols struct {
+		Id   int64
+		ColA string
+		ColB string
+	}
+
+	assert.NoError(t, prepareEngine())
+	assertSync(t, new(FindMapCols))
+
+	var objs = make(map[int64]*FindMapCols)
+	err := testEngine.Cols("col_a, col_b").Find(&objs)
+	assert.Error(t, err)
+	assert.True(t, IsErrPrimaryKeyNoSelected(err))
+
+	err = testEngine.Cols("id, col_a, col_b").Find(&objs)
+	assert.NoError(t, err)
+}

From cbb73a063d264b8f4289143bc52a5a79df5a9e16 Mon Sep 17 00:00:00 2001
From: Lunny Xiao <xiaolunwen@gmail.com>
Date: Tue, 20 Aug 2019 20:03:22 +0800
Subject: [PATCH 2/2] fix tests

---
 session_find_test.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/session_find_test.go b/session_find_test.go
index 3be6a51b9..e48343608 100644
--- a/session_find_test.go
+++ b/session_find_test.go
@@ -812,11 +812,15 @@ func TestFindMapCols(t *testing.T) {
 	assert.NoError(t, prepareEngine())
 	assertSync(t, new(FindMapCols))
 
+	id := testEngine.GetColumnMapper().Obj2Table("Id")
+	colA := testEngine.GetColumnMapper().Obj2Table("ColA")
+	colB := testEngine.GetColumnMapper().Obj2Table("ColB")
+
 	var objs = make(map[int64]*FindMapCols)
-	err := testEngine.Cols("col_a, col_b").Find(&objs)
+	err := testEngine.Cols(colA, colB).Find(&objs)
 	assert.Error(t, err)
 	assert.True(t, IsErrPrimaryKeyNoSelected(err))
 
-	err = testEngine.Cols("id, col_a, col_b").Find(&objs)
+	err = testEngine.Cols(id, colA, colB).Find(&objs)
 	assert.NoError(t, err)
 }