Start MySQL implementation: config template, PDO layer and migrations

scripts/migrate.php

@@ -0,0 +1,48 @@
+#!/usr/bin/env php
+<?php
+
+declare(strict_types=1);
+
+require __DIR__ . '/../lib/db.php';
+
+try {
+    $pdo = db();
+} catch (Throwable $e) {
+    fwrite(STDERR, "DB connection failed: " . $e->getMessage() . PHP_EOL);
+    exit(1);
+}
+
+$pdo->exec('CREATE TABLE IF NOT EXISTS migrations (name VARCHAR(191) PRIMARY KEY, applied_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci');
+
+$files = glob(__DIR__ . '/../migrations/*.sql') ?: [];
+sort($files, SORT_NATURAL);
+
+$check = $pdo->prepare('SELECT 1 FROM migrations WHERE name = :name');
+$mark = $pdo->prepare('INSERT INTO migrations(name) VALUES (:name)');
+
+foreach ($files as $file) {
+    $name = basename($file);
+    $check->execute(['name' => $name]);
+    if ($check->fetchColumn()) {
+        echo "skip {$name}" . PHP_EOL;
+        continue;
+    }
+
+    echo "apply {$name}" . PHP_EOL;
+    $sql = file_get_contents($file);
+    if ($sql === false) {
+        throw new RuntimeException("Cannot read {$file}");
+    }
+
+    $pdo->beginTransaction();
+    try {
+        $pdo->exec($sql);
+        $mark->execute(['name' => $name]);
+        $pdo->commit();
+    } catch (Throwable $e) {
+        $pdo->rollBack();
+        throw $e;
+    }
+}
+
+echo "done" . PHP_EOL;