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mybatis-mp 之多表 join，非常简单

日期：2024-06-24点击：243收藏

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多表join

 List<SysUser> list=QueryChain.of(sysUserMapper)  .select(SysUser.class)  .from(SysUser.class)  .join(SysUser.class,SysRole.class)  .list();

join相同表

 List<SysUser> list=QueryChain.of(sysUserMapper)  .select(SysUser.class)  .from(SysUser.class)  .join(SysUser.class,1,SysUser.class,2,on->on.eq(SysUser::getId,1,SysUser::getRole_id,2))  .list();

join子查询

 SubQuery subQuery=SubQuery.create("sub")  .select(SysRole.class)  .from(SysRole.class)  .eq(SysRole::getId,1); List<SysUser> list=QueryChain.of(sysUserMapper)  .select(SysUser.class)  .from(SysUser.class)  .join(SysUser.class,subQuery,on->on.eq(SysUser::getRole_id,subQuery.$(subQuery,SysRole::getId)))  .list();

返回2张相同表字段

 List<SysUserVO> list=QueryChain.of(sysUserMapper)  .select(SysUser.class)  .select(SysUser.class,2)   .from(SysUser.class)  .join(SysUser.class,1,SysUser.class,2,on->on.eq(SysUser::getId,1,SysUser::getRole_id,2))  .returnType(SysUserVO.class)   .list();