Export specific rows from a PostgreSQL table as INSERT SQL script

I have a database schema named: nyummy and a table named cimory:

create table nyummy.cimory (
  id numeric(10,0) not null,
  name character varying(60) not null,
  city character varying(50) not null,
  CONSTRAINT cimory_pkey PRIMARY KEY (id)
);

I want to export the cimory table's data as insert SQL script file. However, I only want to export records/data where the city is equal to 'tokyo' (assume city data are all lowercase).

How to do it?

It doesn't matter whether the solution is in freeware GUI tools or command line (although GUI tools solution is better). I had tried pgAdmin III, but I can't find an option to do this.

Solution 1:

Create a table with the set you want to export and then use the command line utility pg_dump to export to a file:

create table export_table as 
select id, name, city
from nyummy.cimory
where city = 'tokyo'

$ pg_dump --table=export_table --data-only --column-inserts my_database > data.sql

--column-inserts will dump as insert commands with column names.

--data-only do not dump schema.

As commented below, creating a view in instead of a table will obviate the table creation whenever a new export is necessary.

Solution 2:

To export data only use COPY:

COPY (SELECT * FROM nyummy.cimory WHERE city = 'tokio') TO '/path/to/file.csv';

You can export a whole table, only selected columns, or the result of a query as demonstrated. No need to create a table explicitly.

You get a file with one table row per line as plain text (not INSERT commands). Smaller and faster than INSERT commands.

To import the same to another Postgres table of matching structure anywhere (columns in same order, data types compatible!):

COPY other_tbl FROM '/path/to/file.csv';

COPY writes and reads files local to the server, unlike client programs like pg_dump or psql which read and write files local to the client. If both run on the same machine, it doesn't matter much, but it does for remote connections.

There is also the \copy command of psql:

Performs a frontend (client) copy. This is an operation that runs an SQL COPY command, but instead of the server reading or writing the specified file, psql reads or writes the file and routes the data between the server and the local file system. This means that file accessibility and privileges are those of the local user, not the server, and no SQL superuser privileges are required.

Same syntax as above. Just replace COPY with \copy.