MybatisPlus Wrapper 自定义条件构造器

查询条件构造器 QueryWrapper

// lt：less than 小于

// le：less than or equal to 小于等于
// eq：equal to 等于
// ne：not equal to 不等于
// ge：greater than or equal to 大于等于
// gt：greater than 大于

QueryWrapper<FormOrg> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("APP_CODE", appCode);
        queryWrapper.in("ORG_CODE", orgList);
        queryWrapper.eq("APPLY_TYPE_CODE", "");
        queryWrapper.le("BEGIN_DATE", startDate);
        queryWrapper.ge("END_DATE", startDate);
        queryWrapper.eq("TURN_ON_OR_NOT", "1");

List<FormOrg> list = xxxService.list(queryWrapper);

引入lambda，避免我们在代码中写类似的于 APP_CODE 的硬编码 LambdaQueryWrapper<SysUser>

LambdaQueryWrapper<SysUser> queryWrapper = new QueryWrapper<SysUser>().lambda();
// 简化写法如下        
// LambdaQueryWrapper<SysUser> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(SysUser::getUserName, "admin");
        List<SysUser> list = sysUserMapper.selectList(queryWrapper);
        System.out.println(list);

• 链式查询 LambdaQueryChainWrapper （粗体是区别，注意）

 List<SysUser> list1 = new LambdaQueryChainWrapper<>(sysUserMapper)
                .eq(SysUser::getUserName, "admin")
                .list();

查询一条记录，通过id查询某条记录的详情，使用.one()即可

SysUser sysUser = new LambdaQueryChainWrapper<>(sysUserMapper)
                .eq(SysUser::getId, "1")
                .one();

 select 指定查询字段

queryWrapper.select("USER_NAME","USER_CODE");

未完，待续。。。