如何在 psycopg2 中回滚?

How to rollback in psycopg2?

我在 qry2 中强加了一个错误,这样 运行 qry3 假设它可以回滚到 save_1,但事实并非如此。有收获吗?使用 PostgreSql 14.2

qry1 = ('begin;' +
        'savepoint save_1;' +
        'delete from ntnb_cup;')

qry2 = ...
        # Force error

qry3 = 'rollback to save_1;'

try:
    cursor = conn.cursor()
    cursor.execute(qry1)
    conn.commit()
except Exception as err:
    cursor.close()
    conn.close()
    exit()

try:
    cursor.execute(qry2)
    conn.commit()  
except Exception as err:
    cursor.execute(qry3)
    conn.commit()    
finally:
    cursor.close()
    conn.close()
try:
    cursor = conn.cursor()
    cursor.execute(qry1)
    conn.commit()

一旦你承诺,你就是承诺。要保留稍后回滚到保存点的选项,请不要在此处提交。