Merge pull request #1 from aptvision/master

Add support for Postgres databases and other SQL databases

Author: newcron

README.md

@@ -1,4 +1,4 @@
-# dbmigrate - Database Migration Tool for MySQL
+# dbmigrate - Database Migration Tool
 
 dbmigrate is a simple utility to automate changes to your database (schema and contents). This tool is typically
 helpful for automating code deployments or in scenarios, where it is necessary to audit database changes. It's an alternative
@@ -8,6 +8,11 @@ in your hands and like the simplicity of versioned SQL files, then this tool mig
 
 dbmigrate is heavily inspired from [Flyway](http://flywaydb.org/).
 
+dbmigrate currently supports these database engines:
+
+* MySQL
+* PostgreSQL
+
 ### How does it work
 
 All your migration SQL files will be stored in one directory (let's call it the *migrations directory*).
@@ -66,6 +71,10 @@ $pdo = new PDO("mysql:host=yourdbhost;database=yourdb", "youruser", "yourpass");
 call_user_func(new \dbmigrate\Migrate($pdo, new \SplFileInfo("/path/to/your/sql/folder")));
 ```
 
+All the sql files in the "/path/to/your/sql/folder" directory will be read and run against the
+database. Each file will be run inside a single transaction, if anything within that file
+fails then all commands in that file will be rolled back.
+
 ##### Dry-Running Migrations
 
 If you just want to know if your new migration *would* be going to be installed, you can perform a

src/php/Initialize.php

@@ -7,25 +7,42 @@
 use dbmigrate\application\sql\MigrationTablePresenceConstraint;
 use dbmigrate\application\sql\RunMigration;
 use dbmigrate\application\sql\SqlFile;
+use PDO;
 
 class Initialize
 {
+    /**
+     * @var string
+     */
+    private $databaseEngine;
+
+    /**
+     * @var MigrationTablePresenceConstraint
+     */
     private $migrationTablePresenceConstraint;
 
     /** @var  RunMigration */
     private $runMigration;
 
     public function __construct(\PDO $pdo)
     {
+        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+
+        $this->databaseEngine = strtolower($pdo->getAttribute(PDO::ATTR_DRIVER_NAME));
         $this->runMigration = new RunMigration($pdo);
         $this->migrationTablePresenceConstraint = new MigrationTablePresenceConstraint($pdo);
     }
 
 
     public function __invoke()
     {
+        $initScript = __DIR__ . "/../sql/init-{$this->databaseEngine}.sql";
+        if (!file_exists($initScript)) {
+            throw new \Exception("Unsupported database engine: {$this->databaseEngine}. Create a src/sql/init-{$this->databaseEngine}.sql script to support it");
+        }
+
         $this->migrationTablePresenceConstraint->assertTableMissing();
-        $this->runMigration->run(new SqlFile(new \SplFileInfo(__DIR__ . "/../sql/init.sql")));
+        $this->runMigration->run(new SqlFile(new \SplFileInfo($initScript)));
         $this->migrationTablePresenceConstraint->assertTablePresent();
     }
-}
+}

src/php/Migrate.php

@@ -12,6 +12,7 @@
 use dbmigrate\application\sql\LoadMigrations;
 use dbmigrate\application\sql\LogMigration;
 use dbmigrate\application\sql\RunMigration;
+use PDO;
 
 class Migrate
 {
@@ -28,6 +29,7 @@ class Migrate
      */
     public function __construct(\PDO $pdo, \SplFileInfo $sqlDirectory)
     {
+        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
 
         (new MigrationDirectoryValidator())->assertValidMigrationFileDirectory($sqlDirectory);
 

src/php/MigrateDryRun.php

@@ -9,6 +9,7 @@
 use dbmigrate\application\Planner;
 use dbmigrate\application\sql\LoadMigrations;
 use dbmigrate\application\sql\SqlFile;
+use PDO;
 
 class MigrateDryRun
 {
@@ -20,6 +21,8 @@ class MigrateDryRun
 
     public function __construct(\PDO $pdo, \SplFileInfo $sqlDirectory)
     {
+        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+
         (new MigrationDirectoryValidator())->assertValidMigrationFileDirectory($sqlDirectory);
 
         $this->pdo = $pdo;

src/php/application/sql/MigrationTablePresenceConstraint.php

@@ -39,12 +39,8 @@ public function assertTableMissing()
      */
     private function countRows()
     {
-
-        $statement = $this->pdo->query("show tables like \"installed_migrations\";");
-        try {
-            return $statement->rowCount();
-        } finally {
-            $statement->closeCursor();
-        }
+        return $this->pdo
+            ->query("select count(*) from information_schema.tables where table_name = 'installed_migrations';")
+            ->fetchColumn();
     }
 }

src/php/application/sql/RunMigration.php

@@ -27,17 +27,20 @@ public function __construct(\PDO $pdo)
 
     public function run(SqlFile $file)
     {
-        $statement = $this->pdo->prepare($file->getContents());
+        $this->pdo->beginTransaction();
+
         try {
-            $result = $statement->execute();
+            $result = $this->pdo->query($file->getContents());
             if ($result === false) {
+                $this->pdo->rollBack();
                 throw new \Exception("Query Returned " . var_export($this->pdo->errorInfo(), true));
             }
         } catch (\Exception $e) {
-            throw new MigrationException("Running SQL File " . $file->getFile()->getPathname() . " failed.", $e);
-        } finally {
-            $statement->closeCursor();
+            $this->pdo->rollBack();
+            throw new MigrationException("Error running SQL File " . $file->getFile()->getPathname() . " failed: ".$e->getMessage(), $e);
         }
+
+        $this->pdo->commit();
     }
 
 }

src/sql/init.sql renamed to src/sql/init-mysql.sql

@@ -0,0 +1,8 @@
+create table installed_migrations (
+  id SERIAL,
+  installation_time timestamp DEFAULT current_timestamp,
+  migration_file_name varchar(255) NOT NULL,
+  migration_file_checksum varchar(32) NOT NULL,
+  success boolean,
+  PRIMARY KEY (id)
+)