# 章节末测验
+ 以下查询无法成功执行:  
  + `SELECT name from universe.planets p join universe.moons m WHERE p.id = m.planet_id;`
    + A. `FALSE`
    + B. `TRUE`

```
tidb> DESC universe.planets;
+-----------------------+---------------+------+------+---------+-------+
| Field                 | Type          | Null | Key  | Default | Extra |
+-----------------------+---------------+------+------+---------+-------+
| id                    | bigint(20)    | NO   | PRI  | NULL    |       |
| name                  | char(20)      | NO   | MUL  |         |       |
...
+-----------------------+---------------+------+------+---------+-------+
24 rows in set (0.00 sec)

tidb> DESC universe.moons;
+-----------+---------------+------+------+---------+-------+
| Field     | Type          | Null | Key  | Default | Extra |
+-----------+---------------+------+------+---------+-------+
| id        | bigint(20)    | NO   | PRI  | NULL    |       |
| name      | char(20)      | NO   | MUL  | NULL    |       |
...
+-----------+---------------+------+------+---------+-------+
6 rows in set (0.00 sec)
```
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答案：B