省市区 联动（编辑回显）小例

   <div class="form-group">
                            <label class="col-sm-2 control-label">地址</label>
                            <div class="col-sm-10 form-inline">
                                <input type="hidden" value="${(logistics.province)}" >
                                <input type="hidden" value="${(logistics.city)}" >
                                <input type="hidden" value="${(logistics.county)}" >
                                <select class="form-control" ></select>
                                <select class="form-control" ></select>
                                <select class="form-control" ></select>
                            </div>
                        </div>
                     

<script src="/plugins/provincesCity.js"></script>
<script>
    $(function () {

        initProvince();
    })
</script>

function initProvince() {
    var province = $("#province");
    var city = $("#city");
    var county = $("#country");
    var preProvince = "<option value=\"\">选择省（市）</option>";
    var preCity = "<option value=\"\">选择市（区）</option>";
    var preCounty = "<option value=\"\">选择区（县）</option>";

    //初始化
    province.html(preProvince);
    city.html(preCity);
    county.html(preCounty);

    //加载省下拉列表
    $.ajax({
        type: "POST",
        url: "/system/province/selectProvinces",
        data: {"levelNum": 1}, // 省级别
        dataType: 'json',
        success: function (data) {
            $.each(data, function (i) {
                if ($("#sProvince").val() == data[i].code) {
                    province.append("<option value=" + data[i].code + " selected=\"selected\">" + data[i].name + "</option>");
                    province.trigger("change");
                }
                province.append("<option value=" + data[i].code + ">" + data[i].name + "</option>");
            });
        }, error: function () {
            alert("错了");
        }
    });

    //省 下拉选择发生变化触发的事件
    province.change(function () {
        //province.val() : 返回是每个省对应的下标,序号从0开始
        if (province.val() != "") {
            city.html(preCity);
            var levelNum = 2;//市级别
            $.ajax({
                type: "POST",
                url: "/system/province/selectProvinces",
                data: {levelNum: levelNum, parentCode: province.val()},
                dataType: 'json',
                success: function (data) {
                    $.each(data, function (i) {
                        if ($("#sCity").val() == data[i].code) {
                            city.append("<option value=" + data[i].code + " selected=\"selected\">" + data[i].name + "</option>");
                            city.trigger("change");
                        }
                        city.append("<option value=" + data[i].code + ">" + data[i].name + "</option>");
                    });
                }, error: function () {
                    alert("错了");
                }
            });


        }
    });

    //市 下拉选择发生变化触发的事件
    city.change(function () {
        county.html(preCounty);
        if (city.val() != "") {
            var levelNum = 3; //区级别
            $.ajax({
                type: "POST",
                url: "/system/province/selectProvinces",
                data: {levelNum: levelNum, parentCode: city.val()},
                dataType: 'json',
                success: function (data) {
                    $.each(data, function (i) {
                        if ($("#sCountry").val() == data[i].code) {
                            county.append("<option value=" + data[i].code + " selected=\"selected\">" + data[i].name + "</option>");
                        }
                        county.append("<option value=" + data[i].code + ">" + data[i].name + "</option>");
                    });
                }, error: function () {
                    alert("错了");
                }
            });
        }
    });
}

 <sql >
              and parent_code = #{sysProvinceInfo.parentCode}
          </if>
      </where>
      order by pinyin
  </select>