如何根据第二个 table 的值更新一个 table 中的列？

Question

给定 PostgreSQL 数据库中的以下两个表...

Table observation:

+---------------+---------+
| observationid | deleted | 
+---------------+---------+
|      1        |    F    |
|      2        |    F    |
|      3        |    F    |
+---------------+---------+

Table numericvalue:

+---------------+-------+
| observationid | value | 
+---------------+-------+
|       1       |  999  |
|       2       |   5   |
|       3       |  999  |
+---------------+-------+

只要 numericvalue 中的关联行包含 value，我想将 observation 中所有行的 deleted 列的值设置为 'T'等于 999.

SELECT 查询如下所示：

SELECT *
FROM observation o
INNER JOIN numericvalue n
ON o.observationid = n.observationid
AND n.value = 999;

Answer 1

UPDATE observation ob
SET deleted = 'T'
FROM numericvalue nv
WHERE nv.value = 999
AND nv.observationid = ob.observationid;

Answer 2

UPDATE observation
SET deleted = 'T'
WHERE observationid IN (SELECT observationid FROM numericvalue WHERE value=999)