![]() If you have limited privileges, then you can use the \COPY command because it doesn’t require superuser privileges. The \COPY is an inbuilt command that is used for exporting a PostgreSQL table to a CSV file. How Does the \COPY Command Work in PostgreSQL? In this way, you can export only specific columns of a table. Let’s open the CSV file to see the exported values: And this time, values are separated with “ ”.Įxecute the below statement to export only specific columns of a Postgres table: COPY book_info(book_name) TO 'C:\Windows\Temp\book_info.csv' CSV HEADER The output shows that the desired table has been exported to the CSV file. Open the CSV file from the targeted location to see the exported values: For instance, the below statement will provide the “ ” separated values: COPY book_info TO 'C:\Windows\Temp\book_info1.csv' DELIMITER ' ' CSV HEADER You can specify a delimiter of your choice to separate the table’s values. The output shows that the desired table has been exported to the CSV file successfully. If everything goes fine, you will get the following results: The output shows that five records have been exported. Now run the following command to export the book_info table into a CSV file: COPY book_info TO 'C:\Windows\Temp\book_info.csv' CSV HEADER Let's list down the table details using the SELECT command: SELECT * FROM book_info File_name.csv is the exported CSV file. Path represents a directory where the table will be exported. To achieve this purpose, use the following syntax: COPY tab_name TO 'Path/file_name.csv' CSV HEADER How Does the COPY Statement Work in PostgreSQL?Ĭopy statement is the simplest way to export a table into a CSV file. In this write-up, we will learn different methods to export a Postgres table into a CSV file. In PostgreSQL, you have multiple ways to export a table into a CSV file, such as copy statement, \copy command, or pgAdmin. If the import-table is big it may pay to increase temp_buffers temporarily for the session (first thing in the session): SET temp_buffers = '500MB' - example valueĪdd an index to the temporary table: CREATE INDEX tmp_x_id_idx ON tmp_x(id) Īnd run ANALYZE manually, since temporary tables are not covered by autovacuum / auto-analyze.While working with databases like PostgreSQL, exporting a table into a CSV file or importing a CSV file into a Postgres table is a very common task. Unlike most other meta-commands, the entire remainder of the line is always taken to be the arguments of \copy, and neither variable interpolation nor backquote expansion are performed in the arguments. Special parsing rules apply to the \copy meta-command. Normally, you need the meta-command \\ to switch between psql meta commands and SQL comands in psql, but \copy is an exception to this rule. If you are scripting this in a bash command, be sure to wrap it all in a single psql call. \copy tmp_x FROM '/absolute/path/to/file' (FORMAT csv) The scope of temporary tables is limited to a single session of a single role, so the above has to be executed in the same psql session: CREATE TEMP TABLE. Server, and no SQL superuser privileges are required. This means that fileĪccessibility and privileges are those of the local user, not the Specified file, psql reads or writes the file and routes the dataīetween the server and the local file system. SQL COPY command, but instead of the server reading or writing the ![]() ![]() The psql meta-command \copy works for any db role. Superusers, since it allows reading or writing any file that the ( The manual):ĬOPY naming a file or command is only allowed to database SQL COPY requires superuser privileges for this. If the imported table matches the table to be updated exactly, this may be convenient: CREATE TEMP TABLE tmp_x AS SELECT * FROM tbl LIMIT 0 Ĭreates an empty temporary table matching the structure of the existing table, without constraints. Like: CREATE TEMP TABLE tmp_x (id int, apple text, banana text) - but see belowĬOPY tmp_x FROM '/absolute/path/to/file' (FORMAT csv) ĭROP TABLE tmp_x - else it is dropped at end of session automatically COPY the file to a temporary staging table and update the actual table from there. ![]()
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