/**
* Generate an ID that is unique in a table
* @method uniqueId
* @param {string} $table The name of the table
* @param {string} $field The name of the field to check for uniqueness.
* You should probably have an index starting with this field.
* @param {array} [$where=array()] You can indicate conditions here to limit the search for
* an existing value. The result is an id that is unique within a certain partition.
* @param {array} [$options=array()] Optional array used to override default options:
* @param {integer} [$options.length=8] The length of the ID to generate, after the prefix.
* @param {string} [$options.characters='abcdefghijklmnopqrstuvwxyz'] All the characters from which to construct the id
* @param {string} [$options.prefix=''] The prefix to prepend to the unique id.
* @param {callable} [$options.filter]
* The name of a function that will take the generated string and
* check it. The filter function can modify the string by returning another string,
* or simply reject the string by returning false, in which another string will be
*/
function uniqueId($table, $field, $where = array(), $options = array())
{
$length = 8;
$characters = 'abcdefghijklmnopqrstuvwxyz';
$prefix = '';
extract($options);
$count = strlen($characters);
do {
$id = $prefix;
for ($i = 0; $i < $length; ++$i) {
$id .= $characters[mt_rand(0, $count - 1)];
}
if (!empty($options['filter'])) {
$ret = Q::call($options['filter'], array(compact('id', 'table', 'field', 'where', 'options')));
if ($ret === false) {
continue;
} else {
if ($ret) {
$id = $ret;
}
}
}
$q = $this->select($field, $table)->where(array($field => $id));
if ($where) {
$q->andWhere($where);
}
$rows = $q->limit(1)->fetchAll();
} while ($rows);
return $id;
}
/**
* Gets the SQL that would be executed with the execute() method. See {{#crossLink "Db_Query_Mysql/build"}}{{/crossLink}}.
* @method getSQL
* @param {callable} [$callback=null] If not set, this function returns the generated SQL string.
* If it is set, this function calls $callback, passing it the SQL string, and then returns $this, for chainable interface.
* @param {boolean} [$template=false]
* @return {string|Db_Query} Depends on whether $callback is set or not.
* @throws {Exception} This function calls self::build()
*/
function getSQL($callback = null, $template = false)
{
if (!$template) {
if (isset($this->db->dbname)) {
$this->replacements['{$dbname}'] = $this->db->dbname;
}
if (isset($this->db->prefix)) {
$this->replacements['{$prefix}'] = $this->db->prefix;
}
}
$repres = $this->build();
$keys = array_keys($this->parameters);
usort($keys, array(__CLASS__, 'replaceKeysCompare'));
foreach ($keys as $key) {
$value = $this->parameters[$key];
if ($value instanceof Db_Expression) {
$value2 = $value;
} else {
if (!isset($value)) {
$value2 = "NULL";
} else {
$value2 = $this->reallyConnect()->quote($value);
}
}
if (is_numeric($key) and intval($key) == $key) {
// replace one of the question marks
if (false !== ($pos = strpos($repres, '?'))) {
$repres = substr($repres, 0, $pos) . (string) $value2 . substr($repres, $pos + 1);
}
} else {
// we don't use $repres = str_replace(":$key", "$value2", $repres);
// because we want to replace only one occurrence
if (false !== ($pos = strpos($repres, ":{$key}"))) {
$pos2 = $pos + strlen(":{$key}");
$repres = substr($repres, 0, $pos) . (string) $value2 . substr($repres, $pos2);
}
}
}
foreach ($this->replacements as $k => $v) {
$repres = str_replace($k, $v, $repres);
}
if (isset($callback)) {
$args = array($repres);
Q::call($callback, $args);
return $this;
}
return $repres;
}