恢复 sql 时 psql 无效命令 \N

Question

I'm trying to restore my dump file, but it caused an error:

psql:psit.sql:27485: invalid command \N

Is there a solution? I searched, but I didn't get a clear answer.

Answer 1

Postgres uses "\\N" as substitute symbol for NULL value. But all psql commands start with a backslash "" symbol. You can get these messages, when a copy statement fails, but the loading of dump continues. This message is a false alarm. You have to search all lines prior to this error if you want to see the real reason why COPY statement failed.

Is possible to switch psql to "stop on first error" mode and to find error:

psql -v ON_ERROR_STOP=1

Answer 2

I received the same error message when trying to restore from a binary pg_dump. I simply used pg_restore to restore my dump and completely avoid the \\N errors, eg

pg_restore -c -F t -f your.backup.tar

Explanation of switches:

-f, --file=FILENAME      output file name
-F, --format=c|d|t       backup file format (should be automatic)
-c, --clean              clean (drop) database objects before recreating

Answer 3

我知道这是一篇旧帖子，但我遇到了另一个解决方案：postgis 没有安装在我的新版本上，这导致我在 pg_dump 上出现了同样的错误

Answer 4

I have run into this error in the past as well. Pavel is correct, it is usually a sign that something in the script created by pg_restore is failing. Because of all the "/N" errors, you aren't seeing the real problem at the very top of the output. I suggest:

1. inserting a single, small table (eg, pg_restore --table=orders full_database.dump > orders.dump )
2. if you don't have a small one, then delete a bunch of records out of the restore script - I just made sure the ./ was the last row to be loaded (eg, open orders.dump and delete a bunch of records)
3. watch the standard output, and once you find the problem, you can always drop the table and reload

In my case, I didn't have the "hstore" extension installed yet, so the script was failing at the very top. I installed hstore on the destination database, and I was back in business.

Answer 5

您可以使用 INSERTS 语句和 --inserts 参数生成转储。

Answer 6

Same thing was happened to me today. I handled issue by dumping with --inserts command.

What I do is:

1) pg_dump with inserts:

pg_dump dbname --username=usernamehere --password --no-owner --no-privileges --data-only --inserts -t 'schema."Table"' > filename.sql

2) psql (restore your dumped file)

psql "dbname=dbnamehere options=--search_path=schemaname" --host hostnamehere --username=usernamehere -f filename.sql >& outputfile.txt

Note-1 ) Make sure that adding outputfile will increase speed of import.

Note-2 ) Do not forget to create table with exact same name and columns before importing with psql.

Answer 7

安装 postgresql-(你的版本)-postgis-scripts

Answer 8

In my recent experience, it's possible to get this error when the real problem has nothing to do with escape characters or newlines. In my case, I had created a dump from database A with
pg_dump -a -t table_name > dump.sql
and was trying to restore it to database B with
psql < dump.sql (after updating the proper env vars, of course)
What I finally figured out was that the dump, though it was data-only (the -a option, so that the table structure isn't explicitly part of the dump), was schema-specific. That meant that without manually modifying the dump, I couldn't use a dump generated from schema1.table_name to populate schema2.table_name . Manually modifying the dump was easy, the schema is specified in the first 15 lines or so.

Answer 9

大多数情况下，解决方案是安装postgres-contrib包。

Answer 10

For me using postgreSQL 10 on SUSE 12, I resolved the invalid command \\N error by increasing disk space. Lack of disk space was causing the error for me. You can tell if you are out of disk space if you look at the file system your data is going to in the df -h output. If file system/mount is at 100% used, after doing something like psql -f db.out postgres (see https://www.postgresql.org/docs/current/static/app-pg-dumpall.html ) you likely need to increase the disk space available.

Answer 11

I had the same problem, I created a new database and got invalid command \\N on restore with psql. I solved it by setting the same tablespace with the old database.

For example, old database backup had tablespace "pg_default", I defined the same tablespace to the new database, and the above error has gone!

Answer 12

I followed all these example's and they all failed with the error we are talking about:

Copy a table from one database to another in Postgres

What worked was the syntax with -C , see here:

pg_dump -C -t tableName "postgres://$User:$Password@$Host:$Port/$DBName" | psql "postgres://$User:$Password@$Host:$Port/$DBName"

Also if there are differing Schema's between the two, I find altering one dB's schema to match the others is necessary for Table copies to work, eg:

DROP SCHEMA public;
ALTER SCHEMA originalDBSchema RENAME TO public;

Answer 13

My solution was this:

psql -U your_user your_db < your.file.here.sql  2>&1|more

this way I could read the error message

I hope this helps anybody.

Answer 14

For me it was the ENCODING and LOCALE that differ from the source database. Once I dropped the target DB and recreated it it was working fine.

Answer 15

In my case the problem was a lack of disk space on my target machine. Simply increasing the local storage fixed it for me.

Hope this helps someone ;)

Answer 16

Adding my resolution, incase it helps anyone. I installed postgis but the error wasn't resolved. The --inserts option was not feasible as I had to copy a big schema having tables with thousands of rows. For the same database I didn't see this issue when pg_dump and psql (restore) were run on mac. But the issue came when pg_dump was run on linux machine, the dump file copied to mac and tried for restore. So I opened the dump file in VSCode. It detected unusual line terminators and gave option to remove them. After doing that the dump file restore ran without the invalid command \N errors.

Answer 17

The @farshid-ashuri's answer works fine for me.

I'm using Postgres 14 on Almalinux and messages like its appear. After installing the postgresql14-contrib package, I restored a full dump and no more messages.

*Sorry by my poor english.

Answer 18

check that the columns in the table and the columns in the backup file suitable