如何根据月份查询每月Xxx的总数

我以我的项目根据月份查询每月新增会员的总数为例

Controller

@GetMapping("/getMemberReport.do")
    public R getMemberReport() {
        try {
            // 获取日历对象
            Calendar calendar = Calendar.getInstance();
            //根据当前时间，获取前12个月的日历(当前日历2020-02，12个月前，日历时间2019-03)
            //第一个参数，日历字段
            //第二个参数，要添加到字段中的日期或时间
            calendar.add(Calendar.MONTH, -12);

            List<String> list = new ArrayList<String>();
            for (int i = 0; i < 12; i++) {
                //第一个参数是月份 2018-7
                //第二个参数是月份+1个月
                calendar.add(Calendar.MONTH, 1);
                list.add(new SimpleDateFormat("yyyy-MM").format(calendar.getTime()));
            }

            Map<String, Object> map = new HashMap<String, Object>();
            // 把过去12个月的日期存储到map里面
            map.put("months", list);
            // 查询所有的会员
            List<Integer> memberCount = memberService.findMemberCountByMonth(list);
            map.put("memberCount", memberCount);
            // 查询所有会员
            return R.setResult(ResultCodeEnum.GET_MEMBER_NUMBER_REPORT_SUCCESS).data(map);
        } catch (Exception e) {
            e.printStackTrace();
            return R.setResult(ResultCodeEnum.GET_MEMBER_NUMBER_REPORT_FAIL);
        }
    }

Service

 @Override
    public List<Integer> findMemberCountByMonth(List<String> list) {
        List<Integer> memberCountList = new ArrayList<>();
        if (list != null || list.size() != 0) {
            for (String mouths : list) {
                //String regTime = months+"-31";
                // 获取指定月份的最后一天
                String regTime = DateUtils.getLastDayOfMonth(mouths);
                Integer memberCount = memberMapper.findMemberCountByMouths(regTime);
                memberCountList.add(memberCount);
            }
        }
        return memberCountList;
    }

Mapper

<select id="findMemberCountByMouths" resultType="java.lang.Integer">
	select count(*) from t_member where regTime &lt;=#{regTime}
</select>

前端页面axios

<body class="hold-transition">
	<div id="app">
		<div class="content-header">
			<h1>统计分析<small>会员数量</small></h1>
			<el-breadcrumb separator-class="el-icon-arrow-right" class="breadcrumb">
				<el-breadcrumb-item :to="{ path: '/' }">首页</el-breadcrumb-item>
				<el-breadcrumb-item>统计分析</el-breadcrumb-item>
				<el-breadcrumb-item>会员数量</el-breadcrumb-item>
			</el-breadcrumb>
		</div>
		<div class="app-container">
			<div class="box">
				<!-- 为 ECharts 准备一个具备大小（宽高）的 DOM -->
				<div id="chart1" style="height:600px;"></div>
			</div>
		</div>
	</div>
</body>

<script type="text/javascript">
	// 基于准备好的dom，初始化echarts实例
	var myChart1 = echarts.init(document.getElementById('chart1'));

	// 使用刚指定的配置项和数据显示图表。
	//myChart.setOption(option);

	axios.get("/report/getMemberReport.do").then((res)=>{
		console.log(res)
		myChart1.setOption({
			title: {
				text: '会员数量'
			},
			tooltip: {},
			legend: {
				data:['会员数量']
			},
			xAxis: {
				data: res.data.data.months
			},
			yAxis: {
				type:'value'
			},
			series: [{
				name: '会员数量',
				type: 'line',
				data: res.data.data.memberCount
			}]
		});
	});
</script>