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tinker_tickets/migrations/migrate.php
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jaredandClaude Sonnet 5 fba251b85d Replace illusory transaction wrapping in migrate.php with statement-level resume (#30)
migrate.php wrapped each migration file's statements in
begin_transaction()/rollback(), but MySQL DDL statements cause an
implicit commit — so a rollback couldn't actually undo earlier DDL
already executed within the same file. A migration failing partway
left the DB altered but unrecorded, and the next run retried the
whole file from statement 1, hitting "already exists" errors not on
the safe-to-ignore allowlist and permanently wedging the runner.

Removed the transaction wrapper (it only gave false confidence) and
added a migration_progress table that records the index of the last
successfully-executed statement in each file. A re-run after a
partial failure now resumes right after the last success instead of
re-executing already-applied DDL. Verified against real MariaDB with
a 4-statement migration where statement 3 fails: run 1 correctly
applies statements 1-2 and records progress at index 1; after fixing
the bad statement, run 2 resumes at statement 3, completes, and
clears the progress marker.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015nCxwFFsy8ouMWzn56rPVP
2026-09-08 21:28:32 -04:00

226 lines
7.4 KiB
PHP

#!/usr/bin/env php
<?php
/**
* Database Migration Runner
*
* Runs SQL migration files in order. Tracks completed migrations
* to prevent re-running them.
*
* Usage:
* php migrate.php # Run all pending migrations
* php migrate.php --status # Show migration status
* php migrate.php --dry-run # Show what would be run without executing
*/
// Prevent web access
if (php_sapi_name() !== 'cli') {
http_response_code(403);
exit('CLI access only');
}
require_once dirname(__DIR__) . '/config/config.php';
require_once dirname(__DIR__) . '/helpers/Database.php';
$dryRun = in_array('--dry-run', $argv);
$statusOnly = in_array('--status', $argv);
echo "=== Database Migration Runner ===\n\n";
try {
$conn = Database::getConnection();
} catch (Exception $e) {
echo "Error: Could not connect to database: " . $e->getMessage() . "\n";
exit(1);
}
// Create migrations tracking table if it doesn't exist
$createTable = "CREATE TABLE IF NOT EXISTS migrations (
id INT AUTO_INCREMENT PRIMARY KEY,
filename VARCHAR(255) NOT NULL UNIQUE,
applied_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
INDEX idx_filename (filename)
)";
if (!$conn->query($createTable)) {
echo "Error: Could not create migrations table: " . $conn->error . "\n";
exit(1);
}
// Tracks per-statement progress within a migration file. MySQL DDL statements
// (ALTER/CREATE TABLE, etc.) cause an implicit commit, so begin_transaction()/
// rollback() around a whole file can't actually undo DDL already executed
// earlier in that same file. This table lets a re-run after a partial failure
// resume from the statement after the last one that succeeded, instead of
// re-executing already-applied DDL and wedging on "already exists" errors.
$createProgressTable = "CREATE TABLE IF NOT EXISTS migration_progress (
filename VARCHAR(255) NOT NULL PRIMARY KEY,
last_statement_index INT NOT NULL,
updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
)";
if (!$conn->query($createProgressTable)) {
echo "Error: Could not create migration_progress table: " . $conn->error . "\n";
exit(1);
}
// Get list of completed migrations
$completed = [];
$result = $conn->query("SELECT filename FROM migrations ORDER BY id");
while ($row = $result->fetch_assoc()) {
$completed[] = $row['filename'];
}
// Get list of migration files
$migrationsDir = __DIR__;
$files = glob($migrationsDir . '/*.sql');
sort($files);
if (empty($files)) {
echo "No migration files found.\n";
exit(0);
}
if ($statusOnly) {
echo "Migration Status:\n";
echo str_repeat('-', 60) . "\n";
foreach ($files as $file) {
$filename = basename($file);
$status = in_array($filename, $completed) ? '[DONE]' : '[PENDING]';
echo sprintf(" %s %s\n", $status, $filename);
}
exit(0);
}
// Find pending migrations
$pending = [];
foreach ($files as $file) {
$filename = basename($file);
if (!in_array($filename, $completed)) {
$pending[] = $file;
}
}
if (empty($pending)) {
echo "All migrations are up to date.\n";
exit(0);
}
echo sprintf("Found %d pending migration(s):\n", count($pending));
foreach ($pending as $file) {
echo " - " . basename($file) . "\n";
}
echo "\n";
if ($dryRun) {
echo "[DRY RUN] No changes made.\n";
exit(0);
}
// Run pending migrations
$success = 0;
$failed = 0;
foreach ($pending as $file) {
$filename = basename($file);
echo "Running: $filename... ";
$sql = file_get_contents($file);
if ($sql === false) {
echo "FAILED (could not read file)\n";
$failed++;
continue;
}
// Execute migration statement-by-statement, tracking progress as we go.
// No begin_transaction()/rollback() here: DDL statements auto-commit in
// MySQL/MariaDB regardless, so a transaction wrapper around the whole
// file would only create the illusion of atomicity while giving no real
// protection. Instead, each statement commits immediately (autocommit),
// and its index is durably recorded so a later re-run can resume exactly
// where a previous run left off rather than re-executing already-applied
// DDL.
try {
// Split by semicolon but respect statements properly
// Note: This doesn't handle semicolons in strings, but our migrations are simple
$statements = array_values(array_filter(
array_map('trim', explode(';', $sql)),
function($stmt) {
// Remove comments and check if there's actual SQL
$cleaned = preg_replace('/--.*$/m', '', $stmt);
return !empty(trim($cleaned));
}
));
$resumeFrom = 0;
$progressStmt = $conn->prepare(
"SELECT last_statement_index FROM migration_progress WHERE filename = ?"
);
$progressStmt->bind_param('s', $filename);
$progressStmt->execute();
$progressRow = $progressStmt->get_result()->fetch_assoc();
$progressStmt->close();
if ($progressRow) {
$resumeFrom = (int)$progressRow['last_statement_index'] + 1;
echo "\n Resuming from statement " . ($resumeFrom + 1) . " of " . count($statements)
. " after a previous partial failure... ";
}
foreach ($statements as $index => $statement) {
if ($index < $resumeFrom) {
continue;
}
if (!$conn->query($statement)) {
// Some "errors" are acceptable (like "index already exists")
$error = $conn->error;
if (strpos($error, 'Duplicate key name') !== false ||
strpos($error, 'already exists') !== false) {
// Index already exists, that's fine
} else {
throw new Exception($error);
}
}
// Record progress after every statement so a later run can
// resume from here even if a subsequent statement fails.
$upsert = $conn->prepare(
"INSERT INTO migration_progress (filename, last_statement_index) VALUES (?, ?)
ON DUPLICATE KEY UPDATE last_statement_index = VALUES(last_statement_index)"
);
$upsert->bind_param('si', $filename, $index);
$upsert->execute();
$upsert->close();
}
// Record the migration as fully complete and clear its progress marker
$stmt = $conn->prepare("INSERT INTO migrations (filename) VALUES (?)");
$stmt->bind_param('s', $filename);
if (!$stmt->execute()) {
throw new Exception("Could not record migration: " . $conn->error);
}
$clearProgress = $conn->prepare("DELETE FROM migration_progress WHERE filename = ?");
$clearProgress->bind_param('s', $filename);
$clearProgress->execute();
$clearProgress->close();
echo "OK\n";
$success++;
} catch (Exception $e) {
// Nothing to roll back: every statement up to the failure already
// committed (DDL implicitly, everything else via autocommit). The
// progress marker recorded above reflects exactly how far this file
// got, so the next run will resume right after the last success.
echo "FAILED (" . $e->getMessage() . ")\n";
$failed++;
}
}
echo "\n";
echo "=== Migration Complete ===\n";
echo sprintf(" Success: %d\n", $success);
echo sprintf(" Failed: %d\n", $failed);
exit($failed > 0 ? 1 : 0);