成员替换，创建会话，人员先删除后写入

src/server/models/sessions/sessions.js

@@ -49,6 +49,10 @@ class Sessions extends RedisModel {
        //创建session到mysql
        self.createSessionToMysql(sessionId, name, type, participantArray, messageId, function (err, res) {
            if (err) {
                if (handler) {
                    handler(err, null);
                    return;
                }
                ModelUtil.emitError(self.eventEmitter, {message: err, status: -1}, null);
            } else {
                //创建session到redis
@@ -198,12 +202,11 @@ class Sessions extends RedisModel {
            //查找该sessionId是否存在存在则直接返回实例
            SessionRepo.findOne(sessionId, function (err, res) {
                if (res.length > 0) {//已经存在
                    for (let i in participantArray) {
                        //更新成员
                        Participants.saveParticipantsToMysql(sessionId, participantArray, function (err, update) {
                            handler(null, res[0]);
                        })
                    }
                    Participants.saveParticipantsToMysql(sessionId, participantArray, function (err, update) {
                        handler(null, res[0]);
                        return;
                    })
                } else {
                    let createDate = new Date();
                    let session = {
@@ -220,7 +223,6 @@ class Sessions extends RedisModel {
                            handler(err, null);
                            return;
                        }
                        ;
                        callCreateParticipants(session);
                    })
@@ -234,42 +236,12 @@ class Sessions extends RedisModel {
                if (err) {
                    handler(err, null);
                    return;
                }else{
                    handler(null, session);
                    return;
                }
                // callBeginTrans(session);
            })
        }
        //流程5-发起session会话
        function callBeginTrans(session) {
            let mesDate = new Date();
            let message = {
                sender_id: "system",
                sender_name: "system",
                content_type: 6,
                content: "会话创建成功",
                timestamp: mesDate,
                id: messageId
            };
            session.last_sender_id = message.sender_id;
            session.last_sender_name = message.sender_name;
            session.last_message_time = mesDate.getTime();
            session.last_content = message.content;
            session.last_content_type = message.content_type;
            SessionRepo.updateSessionLastStatus(message.sender_id,
                message.sender_name,
                message.timestamp,
                message.content,
                message.content_type,
                sessionId, function (err, res) {
                    if (err) {
                        handler(err, null);
                        return;
                    }
                    handler(null, session);
                });
        }
    }
    /**