queryWrapper and和or嵌套查询

在使用MyBatis-Plus时，我们可以通过QueryWrapper来构建复杂的查询条件，其中可以使用and和or来嵌套条件。以下是一个使用and和or嵌套条件的例子：

1. and ( ... or ... or...) 格式

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.IService;
 
// 假设有一个实体类Entity和对应的服务类IService
public class Entity {
    private Integer id;
    private String name;
    private Integer age;
    // 省略其他字段、构造函数、getter和setter方法
}
 
public interface IEntityService extends IService {
    // 其他业务方法
}
 
// 使用QueryWrapper构建查询条件
QueryWrapper queryWrapper = new QueryWrapper();
queryWrapper.eq("name", "Alice") // 外层and条件
           .and(i -> i.eq("age", 25).or().eq("age", 30)); // 嵌套and条件，其中包含or条件
 
// 使用服务类进行查询
List result = entityService.list(queryWrapper);

@GetMapping(value = "/list")
    public Result queryPageList(YwglInfo ywglInfo,
     @RequestParam(name = "pageNo", defaultValue = "1") Integer pageNo,
     @RequestParam(name = "pageSize", defaultValue = "10") Integer pageSize,
     HttpServletRequest req) {
        QueryWrapper queryWrapper = QueryGenerator.initQueryWrapper(ywglInfo, req.getParameterMap());
        String kh = req.getParameter("kh");
        if (StringUtils.isNotEmpty(kh)){
            //原来bug sql
            //queryWrapper.eq("send_addr",kh).or().eq("receive_addr",kh);
            queryWrapper.and(wrapper -> wrapper.eq("send_addr",kh).or().eq("receive_addr",kh));
        }
        Page page = new Page(pageNo, pageSize);
        IPage pageList = ywglInfoService.page(page, queryWrapper);
        return Result.OK(pageList);
    }

打印出来的正确SQL如下 

send_type = '0'并且(send_addr = '4224' 或者 receive_addr = '4214')

SELECT send_addr, send_type, receive_addr, receive_type,create_time, create_by, state_desc, comm_type, sfsc, send_time 
FROM ywglinfo WHERE
 (send_type = '0' AND (send_addr = '4224' OR receive_addr = '4214')) 
ORDER BY create_time DESC

错误SQL少了括号

send_type = '0'并且send_addr = '4224' 或者 receive_addr = '4214'

SELECT send_addr, send_type, receive_addr, receive_type,create_time, create_by, state_desc, comm_type, sfsc, send_time 
FROM ywglinfo WHERE 
(send_type = '0' AND send_addr = '4224' OR receive_addr = '4214') 
ORDER BY create_time DESC

2. or ( ... and  ... and ...)  格式

年纪既不等于6也不等于33

wrapper.or(wrapper -> wrapper.ne("age", 6).ne("age",33);