I'm connecting to a postgres db over SQL Alchemy. In testing COPY works great for appending rows to a local db--it's very fast.
COPY ratings FROM '/path/blah.csv' DELIMITER ',' CSV;
However, what I would like to do is COPY a CSV file over the SQL Alchemy connection into a remote postgres db. PG documentation indicates that something like
COPY ratings FROM STDIN '/path/blah.csv' DELIMITER ',' CSV;
might work. But it doesn't. I've tried a bunch of reasonable variations.
Ideas? Thanks for any help, and my apologies if this question is redundant.
I'm not an expert with SqlAlchemy, but I've used copy_from for a "file like" object (aka stream) many times with Psycopg2. And I think you can specify Psycopg2 dialect in SqlAlchemy. Please see the following documentation for SqlAlchemy and copy_from in Psycopg2.
Again, never done it. Worse case, you might have to get a connection via Psycopg2.
Related
I am trying to import a csv file into a postgres database. The csv file is on a local server while the db is on another server. From what I've seen, the recommendations were using \copy.
\COPY tablename from '/path/to/local/file.csv' with csv
But it shows me a syntax error. And the problem is at \copy.
Any suggestion how can I approach this problem?
ERROR: could not open file "C:\Users\lenovo\Downloads\Owners.csv" for reading: Permission denied
HINT: COPY FROM instructs the PostgreSQL server process to read a file. You may want a client-side facility such as psql's \copy.
SQL state: 42501
I am trying to import a csv file into postgresql. But this error pops up. I search everywhere. But i Couldn't get the answer of it PLEASE HELP ME.
THANKS IN ADVANCE!!
COPY mytable FROM /path/thefile.csv WITH CSV,HEADER; is executed by the DBMS server, the .csv-file is read by the server. The server (typically) runs as user postgres, which cannot access arbitrary users's files. (Also: the client and server don't have to be running on the same machine) There are two possible solutions to this:
copy the csv-file to a place where the server can access it, in /tmp/, or somewhere under its home-directory.
use psql's \copy mytable(col1,col2,...) FROM '/path/file.csv'... (slightly different syntax)
The original code is a simple SQL import :
LOAD DATA LOCAL INFILE 'D:/FTP/foo/foo.csv'
INTO TABLE error_logs
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
ESCAPED BY ''
LINES STARTING BY ''
TERMINATED BY '\n'
IGNORE 1 LINES
(Server,Client,Error,Time);
I need to migrate a web portal (from SQL to Postgres[I know there are tools for that, but its not the question]) and the issue is i am no more working on local.
I didn't see anybody ask the question in this way : import .csv from a remote server to a postgres db.
I think i have to use COPY but i dont get the right syntax...
Thanks for your attention.
the copy command is an option to do this.
I had to do this once time.
How to import CSV file data into a PostgreSQL table?
Copying PostgreSQL database to another server
I am attempting to copy data from a csv file into a postgresql database, and am using the following line to do so:
\copy album_tracks FROM 'C:\Users\wMogerty\Desktop\test.csv' WITH (format csv, header true);
However, I am getting the following error and am unsure why:
Error: ERROR: syntax error at or near "\"
Position: 1
SQLState: 42601
ErrorCode: 0
Thanks for any help
\copy is a command in the psql client. It is not supported by the PostgreSQL server. Nor is it part of libpq so it's not supported by alternative clients like PgAdmin-III etc.
You'll need to copy the file to the server yourself and use the COPY command to load it into the database. Or if your client has another interface to the underlying COPY ... FROM STDIN feature used by \copy, like an "import table" or "bulk load" option, you can use that.
I wonder if we should make the PostgreSQL server's parser detect attempts to run \copy as a SQL query and give a better error? Sounds like a great patch for a new developer to try.
I am trying to create a query that will copy data from a CSV file that is located on my computer to a Postgres DB that is on a different computer.
Our Postgres DB is located on another computer, and I work on my own to import and query data. I have successfully copied data from the CSV file on MY computer TO the DB in PSQL Console using the following:
\COPY table_name FROM 'c:\path\to\file.csv' CSV DELIMITER E'\t' HEADER;
But when writing a query using the SQL Editor, I use the same code above without the '\' in the beginning. I get the following error:
ERROR: could not open file "c:\pgres\dmi_vehinventory.csv" for reading: No such file or directory
********** Error **********
ERROR: could not open file "c:\pgres\dmi_vehinventory.csv" for reading: No such file or directory
SQL state: 58P01
I assume the query is actually trying to find the file on the DB's computer rather than my own.
How do I write a query that tells Postgres to look for the file on MY computer rather than the DB's computer?
Any help will be much appreciated !
\COPY is a correct way if you want to upload file from local computer (computer where you've stared psql)
COPY is correct when you want to upload on remote host from remote directory
here is an example, i've connected with psql to remote server:
test=# COPY test(i, i1, i3)
FROM './test.csv' WITH DELIMITER ',';
ERROR: could not open file "./test.csv" for reading: No such file
test=# \COPY test(i, i1, i3)
FROM './test.csv' WITH DELIMITER ',';
test=# select * from test;
i | i1 | i3
---+----+----
1 | 2 | 3
(1 row)
There are several common misconceptions when dealing with PostgreSQL's COPY command.
Even though psql's \COPY FROM '/path/to/file/on/client' command has identical syntax (other than the backslash) to the backend's COPY FROM '/path/to/file/on/server' command, they are totally different. When you include a backslash, psql actually rewrites it to a COPY FROM STDIN command instead, and then reads the file itself and transfers it over the connection.
Executing a COPY FROM 'file' command tells the backend to itself open the given path and load it into a given table. As such, the file must be mapped in the server's filesystem and the backend process must have the correct permissions to read it. However, the upside of this variant is that it is supported by any postgresql client that supports raw sql.
Successfully executing a COPY FROM STDIN places the connection into a special COPY_IN state during which an entirely different (and much simpler) sub-protocol is spoken between the client and server, which allows for data (which may or may not come from a file) to be transferred from the client to the server. As such, this command is not well supported outside of libpq, the official client library for C. If you aren't using libpq, you may or may not be able to use this command, but you'll have to do your own research.
COPY FROM STDIN/COPY TO STDOUT doesn't really have anything to do with standard input or standard output; rather the client needs to speak the sub-protocol on the database connection. In the COPY IN case, libpq provides two commands, one to send data to the backend, and another to either commit or roll back the operation. In the COPY OUT case, libpq provides one function that receives either a row of data or an end of data marker.
I don't know anything about SQL Editor, but it's likely that issuing a COPY FROM STDIN command will leave the connection in an unusable state from its point of view, especially if it's connecting via an ODBC driver. As far as I know, ODBC drivers for PostgreSQL do not support COPY IN.