使用MyBatis XML和QueryWrapper实现动态查询

<select id="selectCode" resultType="java.util.Map">
    SELECT * FROM order
</select>

package com.example.order.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.example.order.entity.Order;
import org.apache.ibatis.annotations.Param;
import java.util.Map;

public interface OrderMapper extends BaseMapper<Order> {
    IPage<Map<String, Object>> selectCode(Page<Map<String, Object>> page, @Param("ew") QueryWrapper<Order> queryWrapper);
}

package com.example.order.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.example.order.dtc.request.OrderQuery;
import com.example.order.entity.Order;
import com.example.order.mapper.OrderMapper;
import com.example.order.service.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Map;

@Service
public class OrderServiceImpl implements OrderService {

    @Autowired
    private OrderMapper orderMapper;

    @Override
    public IPage<Map<String, Object>> selectCode(Page<Map<String, Object>> page, OrderQuery query) {
        QueryWrapper<Order> queryWrapper = new QueryWrapper<>();

        // Add filtering
        if (query.getFilterField() != null && query.getFilterValue() != null) {
            queryWrapper.eq(query.getFilterField(), query.getFilterValue());
        }

        // Add sorting
        if (query.getSortBy() != null) {
            if (query.isAscending()) {
                queryWrapper.orderByAsc(query.getSortBy());
            } else {
                queryWrapper.orderByDesc(query.getSortBy());
            }
        }

        return orderMapper.selectCode(page, queryWrapper);
    }
}

<select id="selectCode" resultType="java.util.Map" parameterType="com.baomidou.mybatisplus.core.conditions.Wrapper">
    SELECT * FROM order
    <where>
        <if test="ew != null">
            ${ew.sqlSegment}
        </if>
    </where>
</select>