对于我的 rails 应用程序，我使用pgloader将本地 sqlite3 文件转换为 postgres 数据库。
为此，我创建了一个 postgres 数据库
createdb my_database_development
我创建了一个 pgload 命令文件
load database
from 'db/production.sqlite3'
into postgresql:///my_database_development
with include drop, create tables, create indexes, reset sequences
set work_mem to '16MB', maintenance_work_mem to '512 MB';
现在将 sqlite 文件加载到 postgres db 中，我认为我没有任何错误。所有的表和记录都被复制了，但是当我查看我的 rails 应用程序时，没有一个记录有索引（或 id）。这是将 sqlite 文件加载到数据库中的输出
simon (master *) Blog-database $ pgloader db/development.sqlite3 postgresql:///my_database_development
2016-08-06T13:57:41.201000+03:00 LOG Main logs in '/tmp/pgloader/pgloader.log'
2016-08-06T13:57:41.222000+03:00 LOG Data errors in '/tmp/pgloader/'
2016-08-06T13:57:41.425000+03:00 WARNING Postgres warning: table "schema_migrations" does not exist, skipping
2016-08-06T13:57:41.626000+03:00 WARNING Postgres warning: table "comments" does not exist, skipping
2016-08-06T13:57:41.627000+03:00 WARNING Postgres warning: table "users" does not exist, skipping
2016-08-06T13:57:41.627000+03:00 WARNING Postgres warning: table "pictures" does not exist, skipping
2016-08-06T13:57:41.828000+03:00 WARNING Postgres warning: table "posts" does not exist, skipping
table name read imported errors time
---------------------- --------- --------- --------- --------------
fetch 0 0 0 0.001s
fetch meta data 8 8 0 0.050s
create, truncate 0 0 0 0.343s
---------------------- --------- --------- --------- --------------
schema_migrations 12 12 0 0.068s
comments 23 23 0 0.014s
users 3 3 0 0.064s
pictures 24 24 0 0.069s
posts 4 4 0 0.055s
index build completion 0 0 0 0.014s
---------------------- --------- --------- --------- --------------
Create Indexes 4 4 0 0.312s
Reset Sequences 0 0 0 0.064s
---------------------- --------- --------- --------- --------------
Total streaming time 66 66 0 0.742s
pgloader 日志看起来像这样
simon pgloader $ cat pgloader.log
2016-08-06T14:23:53.146000+03:00 NOTICE Starting pgloader, log system is ready.
2016-08-06T14:23:53.223000+03:00 LOG Main logs in 'NIL'
2016-08-06T14:23:53.241000+03:00 LOG Data errors in '/tmp/pgloader/'
2016-08-06T14:23:53.241000+03:00 LOG Parsing commands from file #P"/home/simon/Blog-database/sqlite.loader"
2016-08-06T14:23:53.442000+03:00 NOTICE DROP then CREATE TABLES
2016-08-06T14:23:53.443000+03:00 WARNING Postgres warning: table "schema_migrations" does not exist, skipping
2016-08-06T14:23:53.644000+03:00 WARNING Postgres warning: table "comments" does not exist, skipping
2016-08-06T14:23:53.644000+03:00 WARNING Postgres warning: table "users" does not exist, skipping
2016-08-06T14:23:53.645000+03:00 WARNING Postgres warning: table "pictures" does not exist, skipping
2016-08-06T14:23:53.645000+03:00 WARNING Postgres warning: table "posts" does not exist, skipping
2016-08-06T14:23:53.845000+03:00 NOTICE COPY schema_migrations
2016-08-06T14:23:53.846000+03:00 NOTICE CREATE UNIQUE INDEX "unique_schema_migrations" ON "schema_migrations" ("version")
2016-08-06T14:23:53.846000+03:00 NOTICE COPY comments
2016-08-06T14:23:53.847000+03:00 NOTICE CREATE INDEX "index_comments_on_post_id" ON "comments" ("post_id")
2016-08-06T14:23:53.847000+03:00 NOTICE COPY users
2016-08-06T14:23:53.847000+03:00 NOTICE CREATE UNIQUE INDEX "index_users_on_email" ON "users" ("email")
2016-08-06T14:23:53.847000+03:00 NOTICE CREATE UNIQUE INDEX "index_users_on_reset_password_token" ON "users" ("reset_password_token")
2016-08-06T14:23:53.848000+03:00 NOTICE COPY pictures
2016-08-06T14:23:53.848000+03:00 NOTICE COPY posts
2016-08-06T14:23:54.049000+03:00 NOTICE Reset sequences
这是轨道问题吗？难道你不能仅仅复制一个 id ，因为它表现为一个受保护的属性？