Nette\Database\Table\SqlBuilder::checkUniqueTableName PHP Method

    protected function checkUniqueTableName($tableName, $chain)
    {
        if (isset($this->aliases[$tableName]) && '.' . $tableName === $chain) {
            $chain = $this->aliases[$tableName];
        }
        if (isset($this->reservedTableNames[$tableName])) {
            if ($this->reservedTableNames[$tableName] === $chain) {
                return;
            }
            throw new \Nette\InvalidArgumentException("Table alias '{$tableName}' from chain '{$chain}' is already in use by chain '{$this->reservedTableNames[$tableName]}'. Please add/change alias for one of them.");
        }
        $this->reservedTableNames[$tableName] = $chain;
    }