Add database upgrade file 27.

etc/db/upgrades/upgrade27-v0.4.0-add-project_configuration-function.sql

@@ -0,0 +1,122 @@
+-- Fix wrong number of missing shots in summary views
+--
+-- New schema version: 0.4.0
+--
+-- ATTENTION:
+--
+-- ENSURE YOU HAVE BACKED UP THE DATABASE BEFORE RUNNING THIS SCRIPT.
+--
+--
+-- NOTE: This upgrade affects all schemas in the database.
+-- NOTE: Each application starts a transaction, which must be committed
+-- or rolled back.
+--
+-- This adapts the schema to the change in how project configurations are
+-- handled (https://gitlab.com/wgp/dougal/software/-/merge_requests/29)
+-- by creating a project_configuration() function which returns the
+-- current project's configuration data.
+--
+-- 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_survey_schema (schema_name text) AS $outer$
+BEGIN
+
+	RAISE NOTICE 'Updating schema %', schema_name;
+	-- We need to set the search path because some of the trigger
+	-- functions reference other tables in survey schemas assuming
+	-- they are in the search path.
+	EXECUTE format('SET search_path TO %I,public', schema_name);
+
+	CREATE OR REPLACE FUNCTION project_configuration()
+		RETURNS jsonb
+		LANGUAGE plpgsql
+		AS $$
+	DECLARE
+		schema_name text;
+		configuration jsonb;
+	BEGIN
+
+		SELECT nspname
+		INTO schema_name
+		FROM pg_namespace
+		WHERE oid = (
+			SELECT pronamespace
+			FROM pg_proc
+			WHERE oid = 'project_configuration'::regproc::oid
+		);
+
+		SELECT meta
+		INTO configuration
+		FROM public.projects
+		WHERE schema = schema_name;
+
+		RETURN configuration;
+	END
+	$$;
+
+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 >= '0.4.0' THEN
+		RAISE EXCEPTION
+			USING MESSAGE='Patch already applied';
+	END IF;
+
+	IF current_db_version != '0.3.12' AND current_db_version != '0.3.13' THEN
+		RAISE EXCEPTION
+			USING MESSAGE='Invalid database version: ' || current_db_version,
+				HINT='Ensure all previous patches have been applied.';
+	END IF;
+
+	FOR row IN
+		SELECT schema_name FROM information_schema.schemata
+		WHERE schema_name LIKE 'survey_%'
+		ORDER BY schema_name
+	LOOP
+		CALL pg_temp.upgrade_survey_schema(row.schema_name);
+	END LOOP;
+END;
+$outer$ LANGUAGE plpgsql;
+
+CALL pg_temp.upgrade();
+
+CALL pg_temp.show_notice('Cleaning up');
+DROP PROCEDURE pg_temp.upgrade_survey_schema (schema_name text);
+DROP PROCEDURE pg_temp.upgrade ();
+
+CALL pg_temp.show_notice('Updating db_schema version');
+INSERT INTO public.info VALUES ('version', '{"db_schema": "0.4.0"}')
+ON CONFLICT (key) DO UPDATE
+	SET value = public.info.value || '{"db_schema": "0.4.0"}' 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
+--