MediaWiki API result

This is the HTML representation of the JSON format. HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format. To see the non-HTML representation of the JSON format, set format=json.
See the complete documentation, or the API help for more information.
{
    "batchcomplete": "",
    "continue": {
        "gatcontinue": "1|14",
        "continue": "gatcontinue||"
    },
    "query": {
        "pages": {
            "2": {
                "pageid": 2,
                "ns": 0,
                "title": "Nabla"
            },
            "5": {
                "pageid": 5,
                "ns": 0,
                "title": "F"
            },
            "6": {
                "pageid": 6,
                "ns": 0,
                "title": "Q"
            },
            "7": {
                "pageid": 7,
                "ns": 0,
                "title": "E"
            },
            "8": {
                "pageid": 8,
                "ns": 0,
                "title": "Epsilon0"
            },
            "9": {
                "pageid": 9,
                "ns": 0,
                "title": "R"
            },
            "10": {
                "pageid": 10,
                "ns": 0,
                "title": "Phi"
            },
            "11": {
                "pageid": 11,
                "ns": 0,
                "title": "S"
            },
            "12": {
                "pageid": 12,
                "ns": 0,
                "title": "Df"
            },
            "13": {
                "pageid": 13,
                "ns": 0,
                "title": "Symbol:DOmega"
            }
        }
    }
}{
    "error": {
        "code": "internal_api_error_DBQueryError",
        "info": "[7f9fc44c2616a46700d1af41] Exception caught: A database query error has occurred. This may indicate a bug in the software.",
        "errorclass": "Wikimedia\\Rdbms\\DBQueryError",
        "*": "Wikimedia\\Rdbms\\DBQueryError at /var/www/html/includes/libs/rdbms/database/Database.php(1198)\nfrom /var/www/html/includes/libs/rdbms/database/Database.php(1198)\n#0 /var/www/html/includes/libs/rdbms/database/Database.php(1182): Wikimedia\\Rdbms\\Database->getQueryException(string, int, string, string)\n#1 /var/www/html/includes/libs/rdbms/database/Database.php(1156): Wikimedia\\Rdbms\\Database->getQueryExceptionAndLog(string, int, string, string)\n#2 /var/www/html/includes/libs/rdbms/database/Database.php(647): Wikimedia\\Rdbms\\Database->reportQueryError(string, int, string, string, bool)\n#3 /var/www/html/includes/libs/rdbms/database/Database.php(1718): Wikimedia\\Rdbms\\Database->query(Wikimedia\\Rdbms\\Query, string)\n#4 /var/www/html/includes/libs/rdbms/database/DBConnRef.php(127): Wikimedia\\Rdbms\\Database->delete(string, array, string)\n#5 /var/www/html/includes/libs/rdbms/database/DBConnRef.php(581): Wikimedia\\Rdbms\\DBConnRef->__call(string, array)\n#6 /var/www/html/includes/libs/rdbms/querybuilder/DeleteQueryBuilder.php(232): Wikimedia\\Rdbms\\DBConnRef->delete(string, array, string)\n#7 /var/www/html/includes/language/LCStoreDB.php(98): Wikimedia\\Rdbms\\DeleteQueryBuilder->execute()\n#8 /var/www/html/includes/language/LocalisationCache.php(1295): LCStoreDB->finishWrite()\n#9 /var/www/html/includes/language/LocalisationCache.php(614): LocalisationCache->recache(string)\n#10 /var/www/html/includes/language/LocalisationCache.php(479): LocalisationCache->initLanguage(string)\n#11 /var/www/html/includes/language/LocalisationCache.php(381): LocalisationCache->loadItem(string, string)\n#12 /var/www/html/includes/language/Language.php(3096): LocalisationCache->getItem(string, string)\n#13 /var/www/html/includes/specialpage/SpecialPageFactory.php(1821): MediaWiki\\Language\\Language->getSpecialPageAliases()\n#14 /var/www/html/includes/specialpage/SpecialPage.php(171): MediaWiki\\SpecialPage\\SpecialPageFactory->getLocalNameFor(string, bool)\n#15 /var/www/html/includes/specialpage/SpecialPage.php(156): MediaWiki\\SpecialPage\\SpecialPage::getTitleValueFor(string, bool, string)\n#16 /var/www/html/includes/api/ApiFormatBase.php(279): MediaWiki\\SpecialPage\\SpecialPage::getTitleFor(string)\n#17 /var/www/html/includes/api/ApiMain.php(2239): MediaWiki\\Api\\ApiFormatBase->closePrinter()\n#18 /var/www/html/includes/api/ApiMain.php(1983): MediaWiki\\Api\\ApiMain->printResult()\n#19 /var/www/html/includes/api/ApiMain.php(943): MediaWiki\\Api\\ApiMain->executeAction()\n#20 /var/www/html/includes/api/ApiMain.php(914): MediaWiki\\Api\\ApiMain->executeActionWithErrorHandling()\n#21 /var/www/html/includes/api/ApiEntryPoint.php(153): MediaWiki\\Api\\ApiMain->execute()\n#22 /var/www/html/includes/MediaWikiEntryPoint.php(200): MediaWiki\\Api\\ApiEntryPoint->execute()\n#23 /var/www/html/api.php(44): MediaWiki\\MediaWikiEntryPoint->run()\n#24 {main}"
    }
}