{"id":52157,"date":"2023-12-29T01:30:42","date_gmt":"2023-12-29T01:30:42","guid":{"rendered":"https:\/\/gufosaggio.net\/i\/what-is-union-sql\/"},"modified":"2023-12-29T01:30:42","modified_gmt":"2023-12-29T01:30:42","slug":"what-is-union-sql","status":"publish","type":"post","link":"https:\/\/gufosaggio.net\/i\/what-is-union-sql\/","title":{"rendered":"What is union SQL?"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_85 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/gufosaggio.net\/i\/what-is-union-sql\/#Loperatore_SQL_UNION\" >L&#8217;operatore SQL UNION<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/gufosaggio.net\/i\/what-is-union-sql\/#Operatori_in_C\" >Operatori in C<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/gufosaggio.net\/i\/what-is-union-sql\/#Namespace_in_Cpp\" >Namespace in Cpp<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/gufosaggio.net\/i\/what-is-union-sql\/#Amicizia_in_C\" >Amicizia in C++<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/gufosaggio.net\/i\/what-is-union-sql\/#Loperatore_in_C\" >L&#8217;operatore &amp; in C++<\/a><\/li><\/ul><\/nav><\/div>\n<h3><span class=\"ez-toc-section\" id=\"Loperatore_SQL_UNION\"><\/span>L&#8217;operatore SQL UNION<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The result-set of two or more SELECT statements can be combined with the UNION operator. <\/p>\n<p>In UNION, ogni SELECT statement deve avere la stessa quantit\u00e0 di columns. <\/p>\n<p>In ogni SELECT statement, le columns devono essere disposte in modo identico.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Operatori_in_C\"><\/span>Operatori in C<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>An operator is a symbol that can control a variable or value. <\/p>\n<p>I tipi di operatori includono arithmetica, logica, condizionale, relazionale, bitwise, assignment e cos\u00ec via.<\/p>\n<p>In C ci sono anche alcuni operatori specifici, come sizeof(), pointer operator, reference operator, ecc.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Namespace_in_Cpp\"><\/span>Namespace in Cpp<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>A namespace \u00e8 un&#8217;area declarativa che offre una gamma di identifiers, come nomi di types, funzioni e variabili, all&#8217;interno. <\/p>\n<p>Namespaces aiutano a prevenire name collisions, che possono verificarsi quando il tuo code base include pi\u00f9 libraries, organizzando il tuo code in gruppi logici.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Amicizia_in_C\"><\/span>Amicizia in C++<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>In C++, una friend function pu\u00f2 accedere a private, protected e public members di una classe. <\/p>\n<p>In the class body, the friend keyword is used to declare the friend function.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Loperatore_in_C\"><\/span>L&#8217;operatore &amp; in C++<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>&quot;Usa l&#8217;indirizzo della variabile&quot; \u00e8 l&#8217;espressione che viene utilizzata prima del nome della variabile.<\/p>\n<p>In C++, l&#8217;ampersand symbol &amp; funge sia da address operator che da reference declarator.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>L&#8217;operatore SQL UNION The result-set of two or more SELECT statements can be combined with the UNION operator. In UNION, ogni SELECT statement deve avere la stessa quantit\u00e0 di columns. In ogni SELECT statement, le columns devono essere disposte in modo identico. Operatori in C An operator is a symbol that can control a variable &#8230; <a title=\"What is union SQL?\" class=\"read-more\" href=\"https:\/\/gufosaggio.net\/i\/what-is-union-sql\/\" aria-label=\"Per saperne di pi\u00f9 su What is union SQL?\">Leggi tutto<\/a><\/p>\n","protected":false},"author":4487,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-52157","post","type-post","status-publish","format-standard","hentry","category-w"],"_links":{"self":[{"href":"https:\/\/gufosaggio.net\/i\/wp-json\/wp\/v2\/posts\/52157","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gufosaggio.net\/i\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gufosaggio.net\/i\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gufosaggio.net\/i\/wp-json\/wp\/v2\/users\/4487"}],"replies":[{"embeddable":true,"href":"https:\/\/gufosaggio.net\/i\/wp-json\/wp\/v2\/comments?post=52157"}],"version-history":[{"count":0,"href":"https:\/\/gufosaggio.net\/i\/wp-json\/wp\/v2\/posts\/52157\/revisions"}],"wp:attachment":[{"href":"https:\/\/gufosaggio.net\/i\/wp-json\/wp\/v2\/media?parent=52157"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gufosaggio.net\/i\/wp-json\/wp\/v2\/categories?post=52157"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gufosaggio.net\/i\/wp-json\/wp\/v2\/tags?post=52157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}