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0.单表+@Fetch 注解 + fetchFilter 方法
@Data
@ResultEntity(SysUser.class)
public class SysUserVo {
private Integer id;
private String userName;
private String password;
private Integer roleId;
private LocalDateTime create_time;
@Fetch(source = SysUser.class, property = "roleId", target = SysRole.class, targetProperty = "id")
private List<SysRoleVo> sysRoles;
}
List<SysUserVO> list = QueryChain.of(sysUserMapper)
.from(SysUser.class)
.fetchFilter(SysUserVO::getRoles,where->where.eq(SysRole::getStatus,1))
.returnType(SysUserVO.class)
.list();
fetchFilter方法是对@Fetch注解的增强，没有特殊要求一般，可忽略
1. 单表查询
SysUser sysUser = QueryChain.of(sysUserMapper)
.eq(SysUser::getId, 1)
.eq(SysUser::getUserName,'admin')
.get();
2.VO 映射
@Data
@ResultEntity(SysUser.class)
public class SysUserVo {
private Integer id;
private String userName;
//字段名字不一样时
@ResultEntityField(property = "password")
private String pwd;
}
SysUserVO sysUserVO = QueryChain.of(sysUserMapper)
.eq(SysUser::getId, 1)
.eq(SysUser::getUserName,'admin')
.returnType(SysUserVO.class)
.list();
3. join 查询
@Data
@ResultEntity(SysUser.class)
public class SysUserVo {
private Integer id;
private String userName;
//字段名字不一样时
@ResultEntityField(property = "password")
private String pwd;
//映射一个对象 1对1
@NestedResultEntity(target = SysRole.class)
prviate SysRole sysRole;
//映射多个对象 1对多
@NestedResultEntity(target = SysRole.class)
prviate List<SysRole> sysRoles;
}
List<SysUserRoleVO> list = QueryChain.of(sysUserMapper)
.from(SysUser.class)
.join(SysUser.class, SysRole.class)
.returnType(SysUserRoleVO.class)
.list();
还有很多很多超级方便有趣的写法，欢迎大家来使用 https://mybatis-mp.cn
例如：
1 . 多表 join A 内嵌 B B 内嵌 C 都可以
2 . 不使用 join 使用 @Fetch 注解 + fetchFilter 方法实现 将 A JOIN B 变成 query A + query B
3 . 使用 @Paging 注解 实现你的 xml 自动分页
4 . 使用 SQL 模板，让你 ORM 更简单更容易扩展，再也不怕被框架限制了