Refactor database layer: convert to DatabaseProvider class with initialization

bin/database/migration.sql

@@ -0,0 +1,22 @@
+CREATE TABLE IF NOT EXISTS users (
+    id SERIAL PRIMARY KEY,
+    login VARCHAR(255) UNIQUE NOT NULL,
+    pwd_hash VARCHAR(255) NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS geopositions (
+    id SERIAL PRIMARY KEY,
+    user_id INTEGER NOT NULL REFERENCES users(id),
+    x_value DOUBLE PRECISION NOT NULL,
+    y_value DOUBLE PRECISION NOT NULL,
+    datetime TIMESTAMP NOT NULL DEFAULT NOW(),
+    lifetime INTERVAL NOT NULL,
+    expires_at TIMESTAMP NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS logs (
+    id SERIAL PRIMARY KEY,
+    username VARCHAR(255) NOT NULL,
+    action VARCHAR(255) NOT NULL,
+    datetime TIMESTAMP NOT NULL DEFAULT NOW()
+);