/**
* return the column default value if it is defined
*
* @param SimpleXMLNode $table_name table definition xml node
* @param string $column_name name of column to look up default value
*
* @return string column default value, null if not defined for the $column_name
*/
public static function column_default_value(&$table_node, $column_name, &$node)
{
// find the column node in the table
$nodes = static::inheritance_get_column($table_node, $column_name);
if (is_null($nodes) || count($nodes) != 1) {
throw new exception(count($nodes) . " column elements found via xpath '" . 'column[@name="' . $column_name . '"]' . "' - unexpected!");
}
$column_node =& $nodes[0];
$default_value = NULL;
// if it has a default value defined, use it
if (isset($column_node['default']) && strlen($column_node['default']) > 0) {
$default_value = dbsteward::string_cast($column_node['default']);
if (strcasecmp($column_node['default'], 'null') == 0) {
// the column is allowed to be null and the definition of default is null
// so instead of setting the value, mark the column null
dbsteward::trace('column_default_value ' . $table_node['name'] . '.' . $column_node['name'] . ' default null');
$node['null'] = 'true';
} else {
dbsteward::trace('column_default_value ' . $table_node['name'] . '.' . $column_node['name'] . ' default value ' . $column_node['default']);
$default_value = format::strip_string_quoting($default_value);
}
}
return $default_value;
}
