Bugfixing Prestahop

We get after moving the webshop to another server this error: Fatal error: Call to undefined function mysql_connect() in /home/kaadamandeve/public_html/classes/db/[login to view URL] on line 37 We have tried to upgrade the Prestashop, and then get altso this error in admin Modules: PrestaShopDatabaseException] Duplicate entry '21-1645' for key 'PRIMARY' ALTER TABLE `ps_layered_product_attribute` ADD PRIMARY KEY (`id_attribute`, `id_product`), DROP KEY `id_attribute`, ADD UNIQUE KEY `id_attribute_group` (`id_attribute_group`,`id_attribute`,`id_product`) at line 791 in file classes/db/[login to view URL] 786. if ($webservice_call && $errno) { 787. $dbg = debug_backtrace(); 788. WebserviceRequest::getInstance()->setError(500, '[SQL Error] '.$this->getMsgError().'. From '.(isset($dbg[3]['class']) ? $dbg[3]['class'] : '').'->'.$dbg[3]['function'].'() Query was : '.$sql, 97); 789. } elseif (_PS_DEBUG_SQL_ && $errno && !defined('PS_INSTALLATION_IN_PROGRESS')) { 790. if ($sql) { 791. throw new PrestaShopDatabaseException($this->getMsgError().'<br /><br /><pre>'.$sql.'</pre>'); 792. } 793. 794. throw new PrestaShopDatabaseException($this->getMsgError()); 795. } 796. } DbCore->displayError - [line 425 - classes/db/[login to view URL]] - [1 Arguments] DbCore->query - [line 601 - classes/db/[login to view URL]] - [1 Arguments] DbCore->execute - [line 22 - modules/blocklayered/upgrade/[login to view URL]] - [1 Arguments] upgrade_module_2_0_8 - [line 499 - classes/module/[login to view URL]] - [1 Arguments] ModuleCore->runUpgradeModule - [line 1494 - controllers/admin/[login to view URL]] AdminModulesControllerCore->initContent - [line 189 - classes/controller/[login to view URL]] ControllerCore->run - [line 367 - classes/[login to view URL]] DispatcherCore->dispatch - [line 58 - admin/[login to view URL]]