{
  "summary": [
    {
      "name": "pbl_session_member",
      "title": "PBL 会话成员（复用 world_session，不污染基表）",
      "primary": ["id"],
      "catelog": "relation"
    }
  ],
  "fields": [
    {
      "name": "tenant_id",
      "title": "租户ID(多租户强制打头，由应用层 tenant_scope 写入)",
      "type": "str",
      "length": 32,
      "nullable": "no",
      "default": "0"
    },
    {
      "name": "id",
      "title": "主键ID(应用层 getID/uniqueID 生成的32位字符串)",
      "type": "str",
      "length": 32,
      "nullable": "no"
    },
    {
      "name": "session_id",
      "title": "会话ID(关联 world_session.id，以字符串存储避免跨库类型耦合)",
      "type": "str",
      "length": 32,
      "nullable": "no"
    },
    {
      "name": "user_id",
      "title": "用户ID(rbac.user.id)",
      "type": "str",
      "length": 32,
      "nullable": "no"
    },
    {
      "name": "role_code",
      "title": "会话内角色(teacher/learner/observer)",
      "type": "str",
      "length": 64,
      "nullable": "no",
      "default": "learner"
    },
    {
      "name": "team_id",
      "title": "团队ID(pbl_team.id，未分配为空)",
      "type": "str",
      "length": 32,
      "nullable": "yes"
    },
    {
      "name": "joined_at",
      "title": "加入会话时间",
      "type": "datetime",
      "nullable": "yes"
    },
    {
      "name": "last_seen_at",
      "title": "最近心跳时间",
      "type": "datetime",
      "nullable": "yes"
    },
    {
      "name": "state_version",
      "title": "客户端已见状态版本(广播渲染去重水位)",
      "type": "long",
      "nullable": "no",
      "default": "0"
    },
    {
      "name": "status",
      "title": "成员状态(active/left/banned)",
      "type": "str",
      "length": 64,
      "nullable": "no",
      "default": "active"
    },
    {
      "name": "created_at",
      "title": "创建时间(应用层 curDateString 写入)",
      "type": "datetime",
      "nullable": "no",
      "default": "1970-01-01 00:00:00"
    },
    {
      "name": "updated_at",
      "title": "更新时间(应用层 curDateString 写入)",
      "type": "datetime",
      "nullable": "no",
      "default": "1970-01-01 00:00:00"
    }
  ],
  "indexes": [
    {
      "name": "uk_sm",
      "idxtype": "unique",
      "idxfields": ["tenant_id", "session_id", "user_id"]
    },
    {
      "name": "idx_sm_session_status",
      "idxtype": "index",
      "idxfields": ["tenant_id", "session_id", "status"]
    }
  ],
  "codes": [
    {
      "field": "role_code",
      "table": "appcodes_kv",
      "valuefield": "k",
      "textfield": "v",
      "cond": "parentid='pbl_session_role'"
    },
    {
      "field": "status",
      "table": "appcodes_kv",
      "valuefield": "k",
      "textfield": "v",
      "cond": "parentid='pbl_member_status'"
    }
  ]
}