Question

我使用的声明：

INSERT INTO table (addr2, addr3) 
    SELECT City, State 
    FROM table

我试图扭转，但我不知道如何。

我想找回我的数据。现在，所有列和字段均为null。

Answer 1

您说：

...基本上只是从城市和州复制所有数据，然后将数据放入addr2和addr3.fields

如果要在表的所有行中将所有现有vagrant@vagrant:/vagrant/catalog$ python application.py database has been set up! * Serving Flask app "application" (lazy loading) * Environment: production WARNING: Do not use the development server in a production environment. Use a production WSGI server instead. * Debug mode: on * Running on http://0.0.0.0:5000/ (Press CTRL+C to quit) * Restarting with stat Traceback (most recent call last): File "application.py", line 60, in <module> app.run(host='0.0.0.0', port=5000) File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 943, in run run_simple(host, port, self, **options) File "/usr/local/lib/python2.7/dist-packages/werkzeug/serving.py", line 988, in run_simple run_with_reloader(inner, extra_files, reloader_interval, reloader_type) File "/usr/local/lib/python2.7/dist-packages/werkzeug/_reloader.py", line 332, in run_with_reloader sys.exit(reloader.restart_with_reloader()) File "/usr/local/lib/python2.7/dist-packages/werkzeug/_reloader.py", line 176, in restart_with_reloader exit_code = subprocess.call(args, env=new_environ, close_fds=False) File "/usr/lib/python2.7/subprocess.py", line 523, in call return Popen(*popenargs, **kwargs).wait() File "/usr/lib/python2.7/subprocess.py", line 711, in __init__ errread, errwrite) File "/usr/lib/python2.7/subprocess.py", line 1343, in _execute_child raise child_exception OSError: [Errno 8] Exec format error vagrant@vagrant:/vagrant/catalog$替换为addr2，并将city替换为addr3，则需要state，而不是{ {1}}：

UPDATE

...，其中INSERT是表的名称。

请注意，这将替换您先前为UPDATE foo SET addr2 = city, addr3 = state;和foo拥有的所有值，因此请谨慎使用。如果只想替换addr2处的addr3和addr2，则可以执行以下操作：

addr3

或者，也许：

NULL

或者，根据您使用的SQL引擎，也可以使用UPDATE foo SET addr2 = city WHERE addr2 IS NULL; UPDATE foo SET addr3 = state WHERE addr3 IS NULL;：

UPDATE foo SET addr2 = city, addr3 = state WHERE addr2 IS NULL AND addr3 IS NULL;
UPDATE foo SET addr3 = CONCAT(city, ', ', state) WHERE addr2 IS NOT NULL AND addr3 IS NULL;

因此，删除刚插入的行，然后根据需要ISNULL()其余行。为了安全起见，您可能要先备份数据。

在SQL中执行语句后所有数据为NULL

1 个答案: