dougal-software/etc/db/upgrades/upgrade38-v0.6.0-add-keystore-table.sql

-- Fix final_lines_summary view
--
-- New schema version: 0.6.0
--
-- ATTENTION:
--
-- ENSURE YOU HAVE BACKED UP THE DATABASE BEFORE RUNNING THIS SCRIPT.
--
--
-- NOTE: This upgrade only affects the `public` schema.
-- NOTE: Each application starts a transaction, which must be committed
-- or rolled back.
--
-- This update adds a `keystore` table, intended for storing arbitrary
-- key / value pairs which, unlike, the `info` tables, is not meant to
-- be directly accessible via the API. Its main purpose as of this writing
-- is to store user definitions (see #176, #177, #180).
--
-- To apply, run as the dougal user:
--
-- psql <<EOF
-- \i $THIS_FILE
-- COMMIT;
-- EOF
--
-- NOTE: It can be applied multiple times without ill effect.
--

BEGIN;

CREATE OR REPLACE PROCEDURE pg_temp.show_notice (notice text) AS $$
BEGIN
	RAISE NOTICE '%', notice;
END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE PROCEDURE pg_temp.upgrade_database () AS $outer$
BEGIN

	RAISE NOTICE 'Updating schema %', 'public';
	SET search_path TO public;

	CREATE TABLE IF NOT EXISTS keystore (
		type TEXT NOT NULL,     -- A class of data to be stored
		key TEXT NOT NULL,      -- A key that is unique for the class and access type
		last_modified TIMESTAMP -- To detect update conflicts
			DEFAULT CURRENT_TIMESTAMP,
		data jsonb,
		PRIMARY KEY (type, key)  -- Composite primary key
	);

	-- Create a function to update the last_modified timestamp
	CREATE OR REPLACE FUNCTION update_last_modified()
	RETURNS TRIGGER AS $$
	BEGIN
		NEW.last_modified = CURRENT_TIMESTAMP;
		RETURN NEW;
	END;
	$$ LANGUAGE plpgsql;

	-- Create a trigger that calls the function before each update
	CREATE OR REPLACE TRIGGER update_keystore_last_modified
	BEFORE UPDATE ON keystore
	FOR EACH ROW
	EXECUTE FUNCTION update_last_modified();

END;
$outer$ LANGUAGE plpgsql;

CREATE OR REPLACE PROCEDURE pg_temp.upgrade () AS $outer$
DECLARE
	row RECORD;
	current_db_version TEXT;
BEGIN

	SELECT value->>'db_schema' INTO current_db_version FROM public.info WHERE key = 'version';

	IF current_db_version >= '0.6.0' THEN
		RAISE EXCEPTION
			USING MESSAGE='Patch already applied';
	END IF;

	IF current_db_version != '0.5.4' THEN
		RAISE EXCEPTION
			USING MESSAGE='Invalid database version: ' || current_db_version,
				HINT='Ensure all previous patches have been applied.';
	END IF;

	CALL pg_temp.upgrade_database();
END;
$outer$ LANGUAGE plpgsql;

CALL pg_temp.upgrade();

CALL pg_temp.show_notice('Cleaning up');
DROP PROCEDURE pg_temp.upgrade_database ();
DROP PROCEDURE pg_temp.upgrade ();

CALL pg_temp.show_notice('Updating db_schema version');
INSERT INTO public.info VALUES ('version', '{"db_schema": "0.6.0"}')
ON CONFLICT (key) DO UPDATE
	SET value = public.info.value || '{"db_schema": "0.6.0"}' WHERE public.info.key = 'version';


CALL pg_temp.show_notice('All done. You may now run "COMMIT;" to persist the changes');
DROP PROCEDURE pg_temp.show_notice (notice text);

--
--NOTE Run `COMMIT;` now if all went well
--