Type.php

<?php
class ZendDbSchema_Validate_Db_Schema_Table_Mysql_Column_Type
    extends Zend_Validate_Abstract
{
    const NAME_EMPTY = 'columnTypeEmpty';
    const INVALID    = 'columnTypeInvalid';

    protected $_messageTemplates = array(
        self::NAME_EMPTY => "Column type can not be empty",
        self::INVALID    => "Column type %value% is not a valid type"
    );

    protected $_columnTypes = array(
        'TINYINT',
        'SMALLINT',
        'MEDIUMINT',
        'INT',
        'INTEGER',
        'BIGINT',
        'FLOAT',
        'DOUBLE',
        'DECIMAL',
        'PRECISION',
        'REAL',
        'NUMERIC',

        'CHAR',
        'VARCHAR',
        'TINYTEXT',
        'TINYBLOB',
        'TEXT',
        'BLOB',
        'MEDIUMTEXT',
        'MEDIUMBLOB',
        'LONGTEXT',
        'LONGBLOB',

        'DATE',
        'DATETIME',
        'TIMESTAMP',
        'TIME',
        'YEAR',

        'ENUM',
        'SET',

        'BINARY',
        'VARBINARY',
    );

    public function isValid($value)
    {
        $schema = null;
        if ($value instanceof ZendDbSchema_Db_Schema_Table_Column) {
            $schema = $value;
            $value = $schema->__get('type');
        }
        if (empty($value)) {
            $this->_error(self::NAME_EMPTY);
            return false;
        }
        if ($schema && $schema->isDirty('type')) {
            if (!in_array(strtoupper($value), $this->_columnTypes)) {
                $this->_error(self::INVALID, $value);
                return false;
            }
        }
        return true;
    }
}