fix: add measured values table - sqlite

This commit is contained in:
Markus Pesch 2021-06-04 12:45:33 +02:00
parent 077988b503
commit cc677e0c22
Signed by: volker.raschek
GPG Key ID: 852BCC170D81A982
2 changed files with 279 additions and 0 deletions

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-- All tables with the original data rows must be renamed, because it is not
-- possible to remove existing foreign keys. The tables will be recreated with
-- a new column measured_value_id which reference on the primary key of the
-- table measured values.
--
-- More about why it is not possible to delete a foreign key is described here:
-- https://stackoverflow.com/a/1884893/7652996
ALTER TABLE humidities
RENAME TO humidities_backup;
CREATE TABLE humidities (
id CHAR(36) NOT NULL,
value NUMERIC(10,3) NOT NULL,
date TIMESTAMP NOT NULL,
sensor_id CHAR(36) NOT NULL,
creation_date TIMESTAMP DEFAULT (datetime('now', 'localtime')) NOT NULL,
update_date TIMESTAMP,
CONSTRAINT pk_humidities PRIMARY KEY(id),
CONSTRAINT fk_humidities_sensor_id FOREIGN KEY(sensor_id) REFERENCES sensors(sensor_id) ON DELETE CASCADE ON UPDATE CASCADE
);
ALTER TABLE pressures
RENAME TO pressures_backup;
CREATE TABLE pressures (
id CHAR(36) NOT NULL,
value NUMERIC(10,3) NOT NULL,
date TIMESTAMP NOT NULL,
sensor_id CHAR(36) NOT NULL,
creation_date TIMESTAMP DEFAULT (datetime('now', 'localtime')) NOT NULL,
update_date TIMESTAMP,
CONSTRAINT pk_pressures PRIMARY KEY(id),
CONSTRAINT fk_pressures_sensor_id FOREIGN KEY(sensor_id) REFERENCES sensors(sensor_id) ON DELETE CASCADE ON UPDATE CASCADE
);
ALTER TABLE temperatures
RENAME TO temperatures_backup;
CREATE TABLE temperatures (
id CHAR(36) NOT NULL,
value NUMERIC(10,3) NOT NULL,
date TIMESTAMP NOT NULL,
sensor_id CHAR(36) NOT NULL,
creation_date TIMESTAMP DEFAULT (datetime('now', 'localtime')) NOT NULL,
update_date TIMESTAMP,
CONSTRAINT pk_temperatures PRIMARY KEY(id),
CONSTRAINT fk_temperatures_id FOREIGN KEY(sensor_id) REFERENCES sensors(sensor_id) ON DELETE CASCADE ON UPDATE CASCADE
);
-- Filling tables humidities, pressures and temperatures with the data from the
-- backup table.
INSERT INTO humidities
SELECT
h.id,
h.value,
h.date,
m.sensor_id,
h.creation_date,
h.update_date
FROM humidities_backup h
INNER JOIN measured_values m ON (m.id = h.measured_value_id);
INSERT INTO pressures
SELECT
p.id,
p.value,
p.date,
m.sensor_id,
p.creation_date,
p.update_date
FROM pressures_backup p
INNER JOIN measured_values m ON (m.id = p.measured_value_id);
INSERT INTO temperatures
SELECT
t.id,
t.value,
t.date,
m.sensor_id,
t.creation_date,
t.update_date
FROM temperatures_backup t
INNER JOIN measured_values m ON (m.id = t.measured_value_id);
-- The remaining tables, which were only necessary for the migration,
-- are now removed.
DROP TABLE humidities_backup;
DROP TABLE pressures_backup;
DROP TABLE temperatures_backup;
DROP TABLE measured_values;

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-- 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
);
-- All tables with the original data rows must be renamed, because it is not
-- possible to remove existing foreign keys. The tables will be recreated with
-- a new column measured_value_id which reference on the primary key of the
-- table measured values.
--
-- More about why it is not possible to delete a foreign key is described here:
-- https://stackoverflow.com/a/1884893/7652996
ALTER TABLE humidities
RENAME TO humidities_backup;
CREATE TABLE humidities (
id CHAR(36) NOT NULL,
value NUMERIC(10,3) NOT NULL,
date TIMESTAMP NOT NULL,
measured_value_id CHAR(36) NOT NULL,
creation_date TIMESTAMP DEFAULT (datetime('now', 'localtime')) NOT NULL,
update_date TIMESTAMP,
CONSTRAINT pk_humidities PRIMARY KEY(id),
CONSTRAINT fk_humidities_measured_value_id FOREIGN KEY(measured_value_id) REFERENCES measured_values(id) ON DELETE CASCADE ON UPDATE CASCADE
);
ALTER TABLE pressures
RENAME TO pressures_backup;
CREATE TABLE pressures (
id CHAR(36) NOT NULL,
value NUMERIC(10,3) NOT NULL,
date TIMESTAMP NOT NULL,
measured_value_id CHAR(36) NOT NULL,
creation_date TIMESTAMP DEFAULT (datetime('now', 'localtime')) NOT NULL,
update_date TIMESTAMP,
CONSTRAINT pk_pressures PRIMARY KEY(id),
CONSTRAINT fk_pressures_measured_value_id FOREIGN KEY(measured_value_id) REFERENCES measured_values(id) ON DELETE CASCADE ON UPDATE CASCADE
);
ALTER TABLE temperatures
RENAME TO temperatures_backup;
CREATE TABLE temperatures (
id CHAR(36) NOT NULL,
value NUMERIC(10,3) NOT NULL,
date TIMESTAMP NOT NULL,
measured_value_id CHAR(36) NOT NULL,
creation_date TIMESTAMP DEFAULT (datetime('now', 'localtime')) NOT NULL,
update_date TIMESTAMP,
CONSTRAINT pk_temperatures PRIMARY KEY(id),
CONSTRAINT fk_temperatures_measured_value_id FOREIGN KEY(measured_value_id) REFERENCES measured_values(id) ON DELETE CASCADE ON UPDATE CASCADE
);
-- The following two views are necessary to create a FULL OUTER JOIN via the
-- tables humidities, pressures and temperatures, as this is not supported in
-- SQLite. More about this here:
--
-- https://stackoverflow.com/questions/12759087/full-outer-join-in-sqlite-on-4-tables
CREATE VIEW humidities_pressures AS
SELECT
h.id AS humidity_id,
h.value AS humidity_value,
h.date AS humidity_date,
h.sensor_id AS humidity_sensor_id,
h.creation_date AS humidity_creation_date,
h.update_date AS humidity_update_date,
p.id AS pressure_id,
p.value AS pressure_value,
p.date AS pressure_date,
p.sensor_id AS pressure_sensor_id,
p.creation_date AS pressure_creation_date,
p.update_date AS pressure_update_date
FROM humidities_backup h
LEFT JOIN pressures_backup p ON (h.date = p.date AND h.sensor_id = p.sensor_id)
UNION ALL
SELECT
h.id AS humidity_id,
h.value AS humidity_value,
h.date AS humidity_date,
h.sensor_id AS humidity_sensor_id,
h.creation_date AS humidity_creation_date,
h.update_date AS humidity_update_date,
p.id AS pressure_id,
p.value AS pressure_value,
p.date AS pressure_date,
p.sensor_id AS pressure_sensor_id,
p.creation_date AS pressure_creation_date,
p.update_date AS pressure_update_date
FROM pressures_backup p
LEFT JOIN humidities_backup h ON (p.date = h.date AND p.sensor_id = h.sensor_id)
WHERE h.date IS NULL
AND h.sensor_id IS NULL;
CREATE VIEW joined_values AS
SELECT
hp.*,
t.id AS temperature_id,
t.value AS temperature_value,
t.date AS temperature_date,
t.sensor_id AS temperature_sensor_id,
t.creation_date AS temperature_creation_date,
t.update_date AS temperature_update_date
FROM temperatures_backup t
LEFT JOIN humidities_pressures hp ON (t.date = hp.pressure_date AND t.sensor_id = hp.pressure_sensor_id)
UNION ALL
SELECT
hp.*,
t.id AS temperature_id,
t.value AS temperature_value,
t.date AS temperature_date,
t.sensor_id AS temperature_sensor_id,
t.creation_date AS temperature_creation_date,
t.update_date AS temperature_update_date
FROM humidities_pressures hp
LEFT JOIN temperatures_backup t ON (t.date = hp.pressure_date AND t.sensor_id = hp.pressure_sensor_id)
WHERE t.date IS NULL
AND t.sensor_id IS NULL;
-- The date and the SensorID are used as primary key between the tables
-- humidities, pressures and temperatures. Based on this information, a
-- MeasuredValueID is generated. The data records are then inserted into the
-- table.
INSERT INTO measured_values (id, creation_date, sensor_id)
SELECT
LOWER(HEX(RANDOMBLOB(4)) || '-' || HEX(RANDOMBLOB(2)) || '-' || '4' || SUBSTR(HEX(RANDOMBLOB(2)), 2) || '-' || SUBSTR('AB89', 1 + (ABS(random()) % 4) , 1) || SUBSTR(HEX(RANDOMBLOB(2)), 2) || '-' || HEX(RANDOMBLOB(6))) AS measured_value_id,
CASE WHEN humidity_date IS NOT NULL THEN humidity_date
WHEN pressure_date IS NOT NULL THEN pressure_date
WHEN temperature_date IS NOT NULL THEN temperature_date
ELSE NULL
END date,
CASE WHEN humidity_sensor_id IS NOT NULL THEN humidity_sensor_id
WHEN pressure_sensor_id IS NOT NULL THEN pressure_sensor_id
WHEN temperature_sensor_id IS NOT NULL THEN temperature_sensor_id
ELSE NULL
END sensor_id
FROM joined_values;
-- In the following, the original data records from the backup are restored with
-- the difference that the MeasuredValueID is added as a foreign key based on
-- the date and the SensorID.
INSERT INTO humidities (id, value, date, measured_value_id, creation_date, update_date)
SELECT
jv.humidity_id,
jv.humidity_value,
jv.humidity_date,
(SELECT mv.id FROM measured_values mv WHERE mv.creation_date = jv.humidity_date AND mv.sensor_id = jv.humidity_sensor_id) AS measured_value,
jv.humidity_creation_date,
jv.humidity_update_date
FROM joined_values jv
WHERE humidity_id IS NOT NULL;
INSERT INTO pressures (id, value, date, measured_value_id, creation_date, update_date)
SELECT
jv.pressure_id,
jv.pressure_value,
jv.pressure_date,
(SELECT mv.id FROM measured_values mv WHERE mv.creation_date = jv.pressure_date AND mv.sensor_id = jv.pressure_sensor_id) AS measured_value,
jv.pressure_creation_date,
jv.pressure_update_date
FROM joined_values jv
WHERE pressure_id IS NOT NULL;
INSERT INTO temperatures (id, value, date, measured_value_id, creation_date, update_date)
SELECT
jv.temperature_id,
jv.temperature_value,
jv.temperature_date,
(SELECT mv.id FROM measured_values mv WHERE mv.creation_date = jv.temperature_date AND mv.sensor_id = jv.temperature_sensor_id) AS measured_value,
jv.temperature_creation_date,
jv.temperature_update_date
FROM joined_values jv
WHERE temperature_id IS NOT NULL;
-- The remaining views and tables, which were only necessary for the migration,
-- are now removed.
DROP VIEW humidities_pressures;
DROP VIEW joined_values;
DROP TABLE humidities_backup;
DROP TABLE pressures_backup;
DROP TABLE temperatures_backup;