public function testDiff()
{
$table1 = DBTable::fromSQL('CREATE TABLE test (id int,name varchar(255))');
$table2 = DBTable::fromSQL('CREATE TABLE test (id int,name varchar(255))');
$table3 = DBTable::fromSQL('CREATE TABLE test2 (id int,name varchar(255))');
$table4 = DBTable::fromSQL('CREATE TABLE test3 (id int,name varchar(255))');
$table5 = DBTable::fromSQL('CREATE TABLE test (id char(4),name varchar(255))');
$table6 = DBTable::fromSQL('CREATE TABLE test (no int,name varchar(255))');
$this->assertEquals('', $table1->diff($table2));
$this->assertEquals('ALTER TABLE test RENAME test2', $table1->diff($table3));
$this->assertEquals('ALTER TABLE test RENAME test3', $table1->diff($table4));
$this->assertEquals('ALTER TABLE test CHANGE id id char(4)', $table1->diff($table5));
$this->assertEquals('ALTER TABLE test ADD no int,DROP id', $table1->diff($table6));
}