调试 ErlyDB 和 MySQL
我正在非 erlyweb 环境中试验 ErlyDB，但运气不佳。
我有一个用于测试的“Thing”表和相应的 Thing 模块：
-module(thing).
-export([table/0, fields/0]).
table() ->
thing.
fields() ->
[name, value].
模块本身可以工作 - 我可以使用 ([Thing] = thing:find({name, '=', "test" }))。
然而，当我尝试保存新记录时，情况不太好。
我始终看到以下错误：
mysql_conn:426: fetch <<"BEGIN">> (id <0.97.0>)
mysql_conn:426: fetch <<"INSERT INTO thing(value,name) VALUES ('vtha','blah')">> (id <0.97.0>)
mysql_conn:426: fetch <<"ROLLBACK">> (id <0.97.0>)
** exception exit: {{'EXIT',{badarg,[{erlang,hd,[[]]},
{erlydb_base,'-do_save/1-fun-0-',4},
{mysql_conn,do_transaction,2},
{mysql_conn,loop,1}]}},
{rollback_result,{updated,{mysql_result,[],[],0,[]}}}}
in function erlydb_base:do_save/1
in call from erlydb_base:hook/4
in call from test_thing:test/0
called as test_thing:test()
表存在，凭据有效，并且 SQL 本身很好，因为我可以直接在数据库上执行命令。
我用来保存的代码是：
erlydb:start(mysql, Database),
Thing = thing:new(<<"hello">>, <<"world">>),
thing:save(Thing),
我缺少什么吗？ 是否有某种方法可以从数据库中查看一些更有用的错误消息？
I am experimenting with ErlyDB in a non-erlyweb environment and I am not having much luck.
I have a 'Thing' table for testing, and a corresponding Thing module:
-module(thing).
-export([table/0, fields/0]).
table() ->
thing.
fields() ->
[name, value].
The module itself works - I can query the database fine using ([Thing] = thing:find({name, '=', "test"})).
When I try and save a new record, however things aren't so good.
I consistently see the following error:
mysql_conn:426: fetch <<"BEGIN">> (id <0.97.0>)
mysql_conn:426: fetch <<"INSERT INTO thing(value,name) VALUES ('vtha','blah')">> (id <0.97.0>)
mysql_conn:426: fetch <<"ROLLBACK">> (id <0.97.0>)
** exception exit: {{'EXIT',{badarg,[{erlang,hd,[[]]},
{erlydb_base,'-do_save/1-fun-0-',4},
{mysql_conn,do_transaction,2},
{mysql_conn,loop,1}]}},
{rollback_result,{updated,{mysql_result,[],[],0,[]}}}}
in function erlydb_base:do_save/1
in call from erlydb_base:hook/4
in call from test_thing:test/0
called as test_thing:test()
The table exists, the credentials work, and the SQL itself is fine, as I can execute the command directly on the database.
The code I am using to save is:
erlydb:start(mysql, Database),
Thing = thing:new(<<"hello">>, <<"world">>),
thing:save(Thing),
Is there something I am missing?
Is there some way of viewing some more helpful error messages from the database?
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（2）
查看 erlydb_base 的来源，异常发生在 erlydb调用您的事物模块的 db_pk_fields() 函数。 该函数应该返回一个列表，但显然没有。
Looking at the source of erlydb_base, the exception happens when erlydb calls your thing module's db_pk_fields() function. That function should return a list, but apparently it doesn't.
我可以确认更改 erlydb.erl 中的代码可以解决此问题（来自 邮件列表上的此引用）。
将 erlydb.erl 的第 561 行从改为
：
I can confirm that altering the code in erlydb.erl fixes this problem (from this reference on the mailing list).
Change Line 561 of erlydb.erl from
To: