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N_file := utl_file.fopen('CSVDIR', 'empdata.

The following is an example of a stored procedure in Oracle, which will export the data from the EMP table to a CSV file: Create Or Replace Procedure exp_emp_data Is The following is an example of creating a directory object in Oracle:Įxport Data from a Table to CSV in Oracle Example The directory object in Oracle is a reference to the physical directory on the server. Utl_File.Put_Line(n_file, 'Third line.') Īs I mentioned in the above example, the directory object MY_DIR must exist. Utl_File.Put_Line(n_file, 'Second line.') Utl_File.Put_Line(n_file, 'First line.') The directory object MY_DIR must be exist or create a new one UTL_FILE.FCLOSE(n_file) Basic Example Declare UTL_FILE.PUT_LINE(n_file, 'abc, xyz, xxx') N_file := UTL_FILE.FOPEN('DIR_OBJ', 'YourCSVFileName.csv', 'w', 4000) Open the file in Begin section, it will open the file and return the file handle into the variable n_file Below are the syntax details and the necessary steps to write a file: Syntax and Steps to Write a File Using UTL_FILE - Declare a variable to store file type PHP's PostgreSQL handler ( not PDO) includes very basic pg_copy_from and pg_copy_to functions which copy to/from a PHP array, which may not be efficient for large data sets.In Oracle, the package UTL_FILE contains many procedures and functions for writing a text file. Your application programming language may also have support for pushing or fetching the data, but you cannot generally use COPY FROM STDIN/ TO STDOUT within a standard SQL statement, because there is no way of connecting the input/output stream. We are using psql to export a query/table to CSV and then spyql to convert the CSV to json lines. I then quit psql and listed the file myfile. Thus, file accessibility and access rights depend on the client rather than the server when \copy is used. Is there a way to export postgres table data as json to a file I need the output to be line by line, like. \copy invokes COPY FROM STDIN or COPY TO STDOUT, and then fetches/stores the data in a file accessible to the psql client. Note that there is no terminating, because meta-commands are terminated by newline, unlike SQL commands.ĭo not confuse COPY with the psql instruction \copy.

The psql command-line client has a special "meta-command" called \copy, which takes all the same options as the "real" COPY, but is run inside the client: \copy (Select * From foo) To '/tmp/test.csv' With CSV The underlying syntax for this is the COPY TO STDOUT command, and graphical tools like pgAdmin will wrap it for you in a nice dialog. The Postgres server doesn't need to know what file you're copying to, it just spits out the data and the client puts it somewhere. The other approach is to do the file handling on the client side, i.e. I've written a blog post expanding on this approach, including some examples of functions that export (or import) files and tables meeting strict conditions.

You probably don’t want to let someone invoke your function and add rows on the end of your “users” table… Which tables should the user be able to read/write in the database? This would normally be defined by GRANTs in the database, but the function is now running as a superuser, so tables which would normally be "out of bounds" will be fully accessible.Which files should the user be allowed to read/write on disk? This might be a particular directory, for instance, and the filename might have to have a suitable prefix or extension.The crucial part is that your function is there to perform additional checks, not just by-pass the security - so you could write a function which exports the exact data you need, or you could write something which can accept various options as long as they meet a strict whitelist. That doesn't actually mean you have to be connected as a superuser (automating that would be a security risk of a different kind), because you can use the SECURITY DEFINER option to CREATE FUNCTION to make a function which runs as though you were a superuser. It also needs to be run as a Postgres "superuser" (normally called "root") because Postgres can't stop it doing nasty things with that machine's local filesystem. This approach runs entirely on the remote server - it can't write to your local PC. Copy (Select * From foo) To '/tmp/test.csv' With CSV DELIMITER ',' If you want something easy to re-use or automate, you can use Postgresql's built in COPY command. Do you want the resulting file on the server, or on the client? Server side