Echarts实战案例代码(15)：月收入年龄分段等MYSQL分类统计PHP后台数据管理接口API数据的解决方案

在数据可视化过程中，需要对数据进行分段分类的统计，然后传递给图表进行渲染显示。如下图：

数据库字段

正常的数据库字段为浮点类型，如

po_namepo_incomeA5000.00B3520.00C4920.00D8900.00E12000.00F3512.00G4800.00

而实现的是区间分组，如果将数据直接传递给前端，通过js对象数组解析，步骤繁琐，幸好mysql提供的简单快捷的执行方案。

SQL语句

    public function getIncome()
    {
        global $db, $res;
        dbc();
        @$township = $_POST['township'];
        //@$township = "神头镇";
        $sql = "select COUNT(CASE WHEN orders_income BETWEEN 0 AND 1000 THEN orders_income END) AS income0,COUNT(CASE WHEN orders_income BETWEEN 1000 AND 2000 THEN orders_income END) AS income1,COUNT(CASE WHEN orders_income BETWEEN 2000 AND 3000 THEN orders_income END) AS income2,COUNT(CASE WHEN orders_income BETWEEN 3000 AND 5000 THEN orders_income END) AS income3,COUNT(CASE WHEN orders_income BETWEEN 5000 AND 8000 THEN orders_income END) AS income4,COUNT(CASE WHEN orders_income BETWEEN 8000 AND 12000 THEN orders_income END) AS income5,COUNT(CASE WHEN orders_income >=12000 THEN orders_income END) AS income6 from " . $db->table('orders') . " where 1";
        IF ($township != "") {
            $sql .= " AND orders_workplace =\"" . $township . "\"";
        }
        $sql .= " group by orders_province";
        $row = $db->queryall($sql);
        $res["data"] = $row;
        die(json_encode_lockdata($res));
    }

输入的json为：

{"err":"","res":"","data":[{"income0":"5","income1":"0","income2":"0","income3":"4","income4":"4","income5":"4","income6":"3"}]}

前端调用

    $.ajax({
        type: 'post',
        async: false,
        data: {township: township},
        url: './api/api.php?act=getIncome&token=3cab7ce4142608c0f40c785b5ab5ca24',
        dataType: "json",
        success: function (res) {
            var dataName = ['无', '1000-2000元', '2000-3000元', '3000-5000元', '5000-8000元', '8000-12000元', '12000元以上'];
      
            var dataList = [
                {name: dataName[0], value: res.data[0].income0},
                {name: dataName[1], value: res.data[0].income1},
                {name: dataName[2], value: res.data[0].income2},
                {name: dataName[3], value: res.data[0].income3},
                {name: dataName[4], value: res.data[0].income4},
                {name: dataName[5], value: res.data[0].income5},
                {name: dataName[6], value: res.data[0].income6},
            ]

            //过滤数据为0的数据;
            var v = filterValue(dataList, 0);
            //console.log(v);
            //筛选新的坐标轴name;
            var vn = [];
            if (v) {
                for (var i = 0; i