From 077988b50355b783c307b0d780edb4298f114c30 Mon Sep 17 00:00:00 2001
From: Markus Pesch <markus.pesch@cryptic.systems>
Date: Sat, 29 May 2021 18:58:45 +0200
Subject: [PATCH] fix: add measured values table - postgres

---
 .../ddl/8_table_measured_values.down.sql      |  95 +++++++++++++
 .../ddl/8_table_measured_values.up.sql        | 130 ++++++++++++++++++
 2 files changed, 225 insertions(+)
 create mode 100644 pkg/repository/postgres/ddl/8_table_measured_values.down.sql
 create mode 100644 pkg/repository/postgres/ddl/8_table_measured_values.up.sql

diff --git a/pkg/repository/postgres/ddl/8_table_measured_values.down.sql b/pkg/repository/postgres/ddl/8_table_measured_values.down.sql
new file mode 100644
index 0000000..a416eeb
--- /dev/null
+++ b/pkg/repository/postgres/ddl/8_table_measured_values.down.sql
@@ -0,0 +1,95 @@
+-- Remove constraints to table measured_values
+ALTER TABLE humidities
+DROP CONSTRAINT fk_humidites_measured_value_id;
+
+ALTER TABLE pressures
+DROP CONSTRAINT fk_pressures_measured_value_id;
+
+ALTER TABLE temperatures
+DROP CONSTRAINT fk_temperatures_measured_value_id;
+
+-- Rename measured_value_id to sensor_id
+ALTER TABLE humidities
+RENAME COLUMN measured_value_id TO sensor_id;
+
+ALTER TABLE pressures
+RENAME COLUMN measured_value_id TO sensor_id;
+
+ALTER TABLE temperatures
+RENAME COLUMN measured_value_id TO sensor_id;
+
+-- Add new column measures_value_id with data from sensor_id
+ALTER TABLE humidities
+ADD COLUMN measured_value_id CHAR(36);
+
+UPDATE humidities
+SET measured_value_id=sensor_id;
+
+ALTER TABLE pressures
+ADD COLUMN measured_value_id CHAR(36);
+
+UPDATE pressures
+SET measured_value_id=sensor_id;
+
+ALTER TABLE temperatures
+ADD COLUMN measured_value_id CHAR(36);
+
+UPDATE temperatures
+SET measured_value_id=sensor_id;
+
+-- Update sensor_id's
+UPDATE humidities h
+SET sensor_id = (
+  SELECT m.sensor_id
+  FROM measured_values m
+  WHERE m.id = h.measured_value_id
+);
+
+UPDATE pressures p
+SET sensor_id = (
+  SELECT m.sensor_id
+  FROM measured_values m
+  WHERE m.id = p.measured_value_id
+);
+
+UPDATE temperatures t
+SET sensor_id = (
+  SELECT m.sensor_id
+  FROM measured_values m
+  WHERE m.id = t.measured_value_id
+);
+
+-- Delete sensor_id columns
+ALTER TABLE humidities
+DROP COLUMN measured_value_id;
+
+ALTER TABLE pressures
+DROP COLUMN measured_value_id;
+
+ALTER TABLE temperatures
+DROP COLUMN measured_value_id;
+
+-- Add foreign keys
+ALTER TABLE humidities
+ADD CONSTRAINT fk_humidites_sensor_id
+FOREIGN KEY (sensor_id)
+REFERENCES sensors(sensor_id)
+ON DELETE CASCADE
+ON UPDATE CASCADE;
+
+ALTER TABLE pressures
+ADD CONSTRAINT fk_pressures_sensor_id
+FOREIGN KEY (sensor_id)
+REFERENCES sensors(sensor_id)
+ON DELETE CASCADE
+ON UPDATE CASCADE;
+
+ALTER TABLE temperatures
+ADD CONSTRAINT fk_temperatures_sensor_id
+FOREIGN KEY (sensor_id)
+REFERENCES sensors(sensor_id)
+ON DELETE CASCADE
+ON UPDATE CASCADE;
+
+-- drop measured values table
+DROP TABLE measured_values CASCADE;
diff --git a/pkg/repository/postgres/ddl/8_table_measured_values.up.sql b/pkg/repository/postgres/ddl/8_table_measured_values.up.sql
new file mode 100644
index 0000000..6393670
--- /dev/null
+++ b/pkg/repository/postgres/ddl/8_table_measured_values.up.sql
@@ -0,0 +1,130 @@
+-- Create measures_values table.
+-- This table represent a collection of different measured values, because it
+-- can be possible, that a sensor returns multiple measured values. For example
+-- the BME280 semsor returns humidity, pressure and temperature values.
+CREATE TABLE measured_values (
+  id                      CHAR(36)                                                NOT NULL,
+  sensor_id               CHAR(36)                                                NOT NULL,
+  creation_date           TIMESTAMP WITH TIME ZONE    DEFAULT CURRENT_TIMESTAMP   NOT NULL,
+  update_date             TIMESTAMP WITH TIME ZONE,
+  CONSTRAINT pk_measured_value PRIMARY KEY(id),
+  CONSTRAINT pk_measured_value_sensor_id FOREIGN KEY(sensor_id) REFERENCES sensors(sensor_id) ON DELETE CASCADE ON UPDATE CASCADE
+);
+
+-- Remove constraints to table sensor
+ALTER TABLE humidities
+DROP CONSTRAINT fk_humidites_sensor_id;
+
+ALTER TABLE pressures
+DROP CONSTRAINT fk_pressures_sensor_id;
+
+ALTER TABLE temperatures
+DROP CONSTRAINT fk_temperatures_sensor_id;
+
+-- Rename sensor_id to measured_value_id
+ALTER TABLE humidities
+RENAME COLUMN sensor_id TO measured_value_id;
+
+ALTER TABLE pressures
+RENAME COLUMN sensor_id TO measured_value_id;
+
+ALTER TABLE temperatures
+RENAME COLUMN sensor_id TO measured_value_id;
+
+-- Add new column sensor_id with data from measures_value_id
+ALTER TABLE humidities
+ADD COLUMN sensor_id CHAR(36);
+
+UPDATE humidities
+SET sensor_id=measured_value_id;
+
+ALTER TABLE pressures
+ADD COLUMN sensor_id CHAR(36);
+
+UPDATE pressures
+SET sensor_id=measured_value_id;
+
+ALTER TABLE temperatures
+ADD COLUMN sensor_id CHAR(36);
+
+UPDATE temperatures
+SET sensor_id=measured_value_id;
+
+
+DO $$
+DECLARE
+  f record;
+BEGIN
+  FOR f IN (
+    SELECT
+      md5(random()::text || clock_timestamp()::text)::uuid AS measured_value_id,
+      h.id AS humidity_id,
+      p.id AS pressure_id,
+      t.id AS temperature_id,
+      CASE WHEN h.sensor_id IS NOT NULL THEN h.sensor_id
+           WHEN p.sensor_id IS NOT NULL THEN p.sensor_id
+           WHEN t.sensor_id IS NOT NULL THEN t.sensor_id
+           ELSE NULL
+      END sensor_id
+    FROM pressures p
+      FULL OUTER JOIN temperatures t ON (t.date = p.date AND t.sensor_id = p.sensor_id)
+      FULL OUTER JOIN humidities h ON (h.date = p.date AND h.sensor_id = p.sensor_id)
+  ) LOOP
+
+    -- MEASURED_VALUE
+    INSERT INTO measured_values(id, sensor_id, creation_date, update_date)
+    VALUES (f.measured_value_id, f.sensor_id, NOW(), NULL)
+    ON CONFLICT (
+      id
+    )
+    DO NOTHING;
+
+    -- HUMIDITY
+    UPDATE humidities
+    SET measured_value_id=f.measured_value_id
+    WHERE id=f.humidity_id;
+
+    -- PRESSURE
+    UPDATE pressures
+    SET measured_value_id=f.measured_value_id
+    WHERE id=f.pressure_id;
+
+    -- TEMPERATURES
+    UPDATE temperatures
+    SET measured_value_id=f.measured_value_id
+    WHERE id=f.temperature_id;
+  END LOOP;
+END;
+$$;
+
+-- Delete sensor_id columns
+ALTER TABLE humidities
+DROP COLUMN sensor_id;
+
+ALTER TABLE pressures
+DROP COLUMN sensor_id;
+
+ALTER TABLE temperatures
+DROP COLUMN sensor_id;
+
+-- Add foreign keys
+ALTER TABLE humidities
+ADD CONSTRAINT fk_humidites_measured_value_id
+FOREIGN KEY (measured_value_id)
+REFERENCES measured_values(id)
+ON DELETE CASCADE
+ON UPDATE CASCADE;
+
+ALTER TABLE pressures
+ADD CONSTRAINT fk_pressures_measured_value_id
+FOREIGN KEY (measured_value_id)
+REFERENCES measured_values(id)
+ON DELETE CASCADE
+ON UPDATE CASCADE;
+
+ALTER TABLE temperatures
+ADD CONSTRAINT fk_temperatures_measured_value_id
+FOREIGN KEY (measured_value_id)
+REFERENCES measured_values(id)
+ON DELETE CASCADE
+ON UPDATE CASCADE;