From 2513e09caa48d96cbbe0870bf9cf15db72354d91 Mon Sep 17 00:00:00 2001
From: Lunny Xiao <xiaolunwen@gmail.com>
Date: Thu, 20 Feb 2020 07:52:44 +0000
Subject: [PATCH] Add test for second insert error (#1527)

Add test for second insert error

Reviewed-on: https://gitea.com/xorm/xorm/pulls/1527
---
 error.go               |  2 +-
 session_insert.go      | 27 ++++++++++++++++-----------
 session_insert_test.go | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 52 insertions(+), 12 deletions(-)

diff --git a/error.go b/error.go
index a67527ac..2e9cbfaa 100644
--- a/error.go
+++ b/error.go
@@ -27,7 +27,7 @@ var (
 	// ErrConditionType condition type unsupported
 	ErrConditionType = errors.New("Unsupported condition type")
 	// ErrUnSupportedSQLType parameter of SQL is not supported
-	ErrUnSupportedSQLType = errors.New("unsupported sql type")
+	ErrUnSupportedSQLType = errors.New("Unsupported sql type")
 )
 
 // ErrFieldIsNotExist columns does not exist
diff --git a/session_insert.go b/session_insert.go
index c9859b7a..fb67db16 100644
--- a/session_insert.go
+++ b/session_insert.go
@@ -16,6 +16,9 @@ import (
 	"xorm.io/core"
 )
 
+// ErrNoElementsOnSlice represents an error there is no element when insert
+var ErrNoElementsOnSlice = errors.New("No element on slice when insert")
+
 // Insert insert one or more beans
 func (session *Session) Insert(beans ...interface{}) (int64, error) {
 	var affected int64
@@ -67,21 +70,23 @@ func (session *Session) Insert(beans ...interface{}) (int64, error) {
 			sliceValue := reflect.Indirect(reflect.ValueOf(bean))
 			if sliceValue.Kind() == reflect.Slice {
 				size := sliceValue.Len()
-				if size > 0 {
-					if session.engine.SupportInsertMany() {
-						cnt, err := session.innerInsertMulti(bean)
+				if size <= 0 {
+					return 0, ErrNoElementsOnSlice
+				}
+
+				if session.engine.SupportInsertMany() {
+					cnt, err := session.innerInsertMulti(bean)
+					if err != nil {
+						return affected, err
+					}
+					affected += cnt
+				} else {
+					for i := 0; i < size; i++ {
+						cnt, err := session.innerInsert(sliceValue.Index(i).Interface())
 						if err != nil {
 							return affected, err
 						}
 						affected += cnt
-					} else {
-						for i := 0; i < size; i++ {
-							cnt, err := session.innerInsert(sliceValue.Index(i).Interface())
-							if err != nil {
-								return affected, err
-							}
-							affected += cnt
-						}
 					}
 				}
 			} else {
diff --git a/session_insert_test.go b/session_insert_test.go
index 657d2b12..9cd5b86a 100644
--- a/session_insert_test.go
+++ b/session_insert_test.go
@@ -1067,3 +1067,38 @@ func TestInsertMultiWithOmit(t *testing.T) {
 	assert.EqualValues(t, 3, num)
 	check()
 }
+
+func TestInsertTwice(t *testing.T) {
+	assert.NoError(t, prepareEngine())
+
+	type InsertStructA struct {
+		FieldA int
+	}
+
+	type InsertStructB struct {
+		FieldB int
+	}
+
+	assert.NoError(t, testEngine.Sync2(new(InsertStructA), new(InsertStructB)))
+
+	var sliceA []InsertStructA // sliceA is empty
+	sliceB := []InsertStructB{
+		InsertStructB{
+			FieldB: 1,
+		},
+	}
+
+	ssn := testEngine.NewSession()
+	defer ssn.Close()
+
+	err := ssn.Begin()
+	assert.NoError(t, err)
+
+	_, err = ssn.Insert(sliceA)
+	assert.EqualValues(t, ErrNoElementsOnSlice, err)
+
+	_, err = ssn.Insert(sliceB)
+	assert.NoError(t, err)
+
+	assert.NoError(t, ssn.Commit())
+}