Executing an insert query on each row in results: psycopg2.ProgrammingError: no results to fetch

Question

我在这里错过了什么愚蠢的东西：

>>> cur.execute("select id from tracks")
>>> for row in cur:
...     story = random.choice(fortunes) + random.choice(fortunes)
...     cur.execute("update tracks set story=%s where id=%s", (story, row[0]))
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
psycopg2.ProgrammingError: no results to fetch

但是似乎结果：

>>> cur.execute("select id from tracks")
>>> for row in cur:
...     print(row)
... 
(8,)
(45,)
(12,)
(64,)
(1,)
(6,)

Answer 1

看起来 psycopg2 不允许交错查询（尽管 PostgreSQL 可以在后端做到这一点）。如果初始查询不是很大，最简单的解决方案是将结果合并到一个列表中——只需将 from row in cur: 更改为 from row in cur.fetchall():，你应该是对的。

Executing an insert query on each row in results: psycopg2.ProgrammingError: no results to fetch

Executing an insert query on each row in results: psycopg2.ProgrammingError: no results to fetch

psycopg2

psql