当我尝试做
rake db:reset
或者
rake db:drop
rake db:create
rake db:schema:load
rake db:seed
NoMethodError: undefined method 'fields' for nil:NilClass
当种子出现时,我随机得到一个。这是一个:
[1m[35m (186.0ms)[0m INSERT INTO "schema_migrations" (version) VALUES ('20130318105449')
[1m[36m (187.0ms)[0m [1mINSERT INTO "schema_migrations" (version) VALUES ('20130319154146')[0m
[1m[35m (189.0ms)[0m INSERT INTO "schema_migrations" (version) VALUES ('20130322132730')
[1m[36m (104.0ms)[0m [1mINSERT INTO "schema_migrations" (version) VALUES ('20130322142814')[0m
NoMethodError: undefined method `fields' for nil:NilClass: SELECT COUNT(*)
FROM pg_class c
LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind in ('v','r')
AND c.relname = 'schema_migrations'
AND n.nspname = ANY (current_schemas(false))
这是另一个:
[1m[35m (39.0ms)[0m BEGIN
[1m[36mCategory Exists (107.0ms)[0m [1mSELECT 1 AS one FROM "categories" WHERE "categories"."hash" = 'cat1' LIMIT 1[0m
[1m[35mSQL (124.0ms)[0m INSERT INTO "categories" ("category_id", "created_at", "label", "hash", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id" [["category_id", 58], ["created_at", Mon, 25 Mar 2013 15:07:53 CET +01:00], ["label", "Cat1"], ["hash", "cat1"], ["updated_at", Mon, 25 Mar 2013 15:07:53 CET +01:00]]
[1m[36m (117.0ms)[0m [1mCOMMIT[0m
[1m[35m (162.0ms)[0m BEGIN
[1m[36mCategory Exists (136.0ms)[0m [1mSELECT 1 AS one FROM "categories" WHERE "categories"."hash" = 'cat2' LIMIT 1[0m
[1m[35mSQL (104.0ms)[0m INSERT INTO "categories" ("created_at", "label", "hash", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id" [["created_at", Mon, 25 Mar 2013 15:07:53 CET +01:00], ["label", "Cat2"], ["hash", "cat2"], ["updated_at", Mon, 25 Mar 2013 15:07:53 CET +01:00]]
[1m[36m (99.0ms)[0m [1mCOMMIT[0m
[1m[35m (108.0ms)[0m BEGIN
[1m[36mCategory Exists (173.0ms)[0m [1mSELECT 1 AS one FROM "categories" WHERE "categories"."hash" = 'cat3' LIMIT 1[0m
NoMethodError: undefined method `fields' for nil:NilClass: SELECT 1 AS one FROM "categories" WHERE "categories"."hash" = 'cat3' LIMIT 1
我真的不明白这可能来自哪里。有时我什至没有错误,一切都完美插入。在做了一些测试之后,它似乎取决于插入的速度。如果我从我的开发服务器执行此操作,它几乎总是成功。如果我从我的计算机远程执行此操作,它几乎总是失败。
我在本地使用 ruby 1.9.3,在我的开发服务器上使用 ruby 2。在两者上我都使用 rails4 (edge) 并且我的驱动程序是 postgresql (pg, 没有指定版本)