{"id":2445,"date":"2023-07-22T06:16:57","date_gmt":"2023-07-22T06:16:57","guid":{"rendered":"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/"},"modified":"2023-07-22T06:16:57","modified_gmt":"2023-07-22T06:16:57","slug":"mongodb-trova-duplicati","status":"publish","type":"post","link":"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/","title":{"rendered":"Come trovare duplicati in mongodb"},"content":{"rendered":"<p><\/p>\n<hr>\n<p><span style=\"color: #000000;\">Puoi utilizzare la seguente sintassi per trovare documenti con valori duplicati in MongoDB:<\/span><\/p>\n<pre style=\"background-color: #ececec; font-size: 15px;\"> <strong>db.collection.aggregate([\n    {\" <span style=\"color: #ff0000;\">$group<\/span> \": { \"_id\": \" <span style=\"color: #ff0000;\">$field1<\/span> \", \"count\": { \" <span style=\"color: #ff0000;\">$sum<\/span> \": 1 } } },\n    {\" <span style=\"color: #ff0000;\">$match<\/span> \": {\"_id\" :{ \" <span style=\"color: #ff0000;\">$ne<\/span> \" : null } , \"count\" : {\" <span style=\"color: #ff0000;\">$gt<\/span> \": 1} } }, \n    {\" <span style=\"color: #ff0000;\">$project<\/span> \": {\"name\": \" <span style=\"color: #ff0000;\">$_id<\/span> \", \"_id\": 0} }\n])\n<\/strong><\/pre>\n<p> <span style=\"color: #000000;\">Ecco cosa fa questa sintassi:<\/span><\/p>\n<ul>\n<li> <span style=\"color: #000000;\"><strong>Raggruppa<\/strong> tutti i documenti con lo stesso valore nel campo 1<\/span><\/li>\n<li> <span style=\"color: #000000;\"><strong>Abbina<\/strong> i gruppi che hanno pi\u00f9 di un documento<\/span><\/li>\n<li> <span style=\"color: #000000;\"><strong>Proietta<\/strong> tutti i gruppi che hanno pi\u00f9 di un documento<\/span><\/li>\n<\/ul>\n<p> <span style=\"color: #000000;\">Questa particolare query cerca valori duplicati nella colonna <strong>field1<\/strong> . Modifica semplicemente questo valore per cambiare il campo in cui effettuare la ricerca.<\/span><\/p>\n<p> <span style=\"color: #000000;\">L&#8217;esempio seguente mostra come utilizzare questa sintassi con un <span style=\"padding: 1px; border: 1px solid black;\">team<\/span> di raccolta con i seguenti documenti:<\/span><\/p>\n<pre style=\"background-color: #ececec; font-size: 15px;\"> <strong>db.teams.insertOne({team: \" <span style=\"color: #008000;\">Mavs<\/span> \", position: \" <span style=\"color: #008000;\">Guard<\/span> \", points: <span style=\"color: #ff0000;\">31<\/span> })<\/strong>\n<strong>db.teams.insertOne({team: \" <span style=\"color: #008000;\">Mavs<\/span> \", position: \" <span style=\"color: #008000;\">Guard<\/span> \", points: <span style=\"color: #ff0000;\">22<\/span> })<\/strong>\n<strong>db.teams.insertOne({team: \" <span style=\"color: #008000;\">Rockets<\/span> \", position: \" <span style=\"color: #008000;\">Center<\/span> \", points: <span style=\"color: #ff0000;\">19<\/span> })<\/strong>\n<strong>db.teams.insertOne({team: \" <span style=\"color: #008000;\">Rockets<\/span> \", position: \" <span style=\"color: #008000;\">Forward<\/span> \", points: <span style=\"color: #ff0000;\">26<\/span> })<\/strong>\n<strong>db.teams.insertOne({team: \" <span style=\"color: #008000;\">Cavs<\/span> \", position: \" <span style=\"color: #008000;\">Guard<\/span> \", points: <span style=\"color: #ff0000;\">33<\/span> })<\/strong><\/pre>\n<h3> <span style=\"color: #000000;\"><strong>Esempio: trovare documenti con valori duplicati<\/strong><\/span><\/h3>\n<p> <span style=\"color: #000000;\">Possiamo utilizzare il seguente codice per trovare tutti i valori duplicati nella colonna &#8220;team&#8221;:<\/span><\/p>\n<pre style=\"background-color: #ececec; font-size: 15px;\"> <strong>db.teams.aggregate([\n    {\" <span style=\"color: #ff0000;\">$group<\/span> \": { \"_id\": \" <span style=\"color: #ff0000;\">$team<\/span> \", \"count\": { \" <span style=\"color: #ff0000;\">$sum<\/span> \": 1 } } },\n    {\" <span style=\"color: #ff0000;\">$match<\/span> \": {\"_id\" :{ \" <span style=\"color: #ff0000;\">$ne<\/span> \" : null } , \"count\" : {\" <span style=\"color: #ff0000;\">$gt<\/span> \": 1} } }, \n    {\" <span style=\"color: #ff0000;\">$project<\/span> \": {\"name\": \" <span style=\"color: #ff0000;\">$_id<\/span> \", \"_id\": 0} }\n])<\/strong><\/pre>\n<p> <span style=\"color: #000000;\">Questa query restituisce i seguenti risultati:<\/span><\/p>\n<pre style=\"background-color: #ececec; font-size: 15px;\"> <strong>{ name: 'Rockets' }\n{ name: 'Mavs' }<\/strong><\/pre>\n<p> <span style=\"color: #000000;\">Questo ci dice che i valori &#8220;Rockets&#8221; e &#8220;Mavs&#8221; compaiono pi\u00f9 volte nel campo &#8220;team&#8221;.<\/span><\/p>\n<p> <span style=\"color: #000000;\">Tieni presente che possiamo semplicemente sostituire <strong>$team<\/strong> con <strong>$position<\/strong> per cercare invece valori duplicati nel campo &#8220;posizione&#8221;:<\/span><\/p>\n<pre style=\"background-color: #ececec; font-size: 15px;\"> <strong>db.teams.aggregate([\n    {\" <span style=\"color: #ff0000;\">$group<\/span> \": { \"_id\": \" <span style=\"color: #ff0000;\">$position<\/span> \", \"count\": { \" <span style=\"color: #ff0000;\">$sum<\/span> \": 1 } } },\n    {\" <span style=\"color: #ff0000;\">$match<\/span> \": {\"_id\" :{ \" <span style=\"color: #ff0000;\">$ne<\/span> \" : null } , \"count\" : {\" <span style=\"color: #ff0000;\">$gt<\/span> \": 1} } }, \n    {\" <span style=\"color: #ff0000;\">$project<\/span> \": {\"name\": \" <span style=\"color: #ff0000;\">$_id<\/span> \", \"_id\": 0} }\n])<\/strong><\/pre>\n<p> <span style=\"color: #000000;\">Questa query restituisce i seguenti risultati:<\/span><\/p>\n<pre style=\"background-color: #ececec; font-size: 15px;\"> <strong>{ name: 'Guard' }\n<\/strong><\/pre>\n<p> <span style=\"color: #000000;\">Questo ci dice che \u201cGuardia\u201d appare pi\u00f9 volte nel campo \u201cposizione\u201d.<\/span><\/p>\n<h3> <span style=\"color: #000000;\"><strong>Risorse addizionali<\/strong><\/span><\/h3>\n<p> <span style=\"color: #000000;\">I seguenti tutorial spiegano come eseguire altre operazioni comuni in MongoDB:<\/span><\/p>\n<p> <a href=\"https:\/\/statorials.org\/it\/mongodb-aggiungi-campo\/\" target=\"_blank\" rel=\"noopener\">MongoDB: come aggiungere un nuovo campo a una raccolta<\/a><br \/> <a href=\"https:\/\/statorials.org\/it\/gruppo-mongodb-per-numero\/\" target=\"_blank\" rel=\"noopener\">MongoDB: come raggruppare e contare<\/a><br \/> <a href=\"https:\/\/statorials.org\/it\/gruppo-mongodb-per-piu-campi\/\" target=\"_blank\" rel=\"noopener\">MongoDB: come raggruppare per pi\u00f9 campi<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Puoi utilizzare la seguente sintassi per trovare documenti con valori duplicati in MongoDB: db.collection.aggregate([ {&#8221; $group &#8220;: { &#8220;_id&#8221;: &#8221; $field1 &#8220;, &#8220;count&#8221;: { &#8221; $sum &#8220;: 1 } } }, {&#8221; $match &#8220;: {&#8220;_id&#8221; :{ &#8221; $ne &#8221; : null } , &#8220;count&#8221; : {&#8221; $gt &#8220;: 1} } }, {&#8221; $project &#8220;: {&#8220;name&#8221;: [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v21.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Come trovare duplicati in MongoDB \u2013 Statorials<\/title>\n<meta name=\"description\" content=\"Questo tutorial spiega come trovare valori duplicati in MongoDB, con diversi esempi.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/\" \/>\n<meta property=\"og:locale\" content=\"it_IT\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Come trovare duplicati in MongoDB \u2013 Statorials\" \/>\n<meta property=\"og:description\" content=\"Questo tutorial spiega come trovare valori duplicati in MongoDB, con diversi esempi.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/\" \/>\n<meta property=\"og:site_name\" content=\"Statorials\" \/>\n<meta property=\"article:published_time\" content=\"2023-07-22T06:16:57+00:00\" \/>\n<meta name=\"author\" content=\"Benjamin anderson\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Benjamin anderson\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minuto\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/\",\"url\":\"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/\",\"name\":\"Come trovare duplicati in MongoDB \u2013 Statorials\",\"isPartOf\":{\"@id\":\"https:\/\/statorials.org\/it\/#website\"},\"datePublished\":\"2023-07-22T06:16:57+00:00\",\"dateModified\":\"2023-07-22T06:16:57+00:00\",\"author\":{\"@id\":\"https:\/\/statorials.org\/it\/#\/schema\/person\/0896f191fb9fb019f2cd8623112cb3ae\"},\"description\":\"Questo tutorial spiega come trovare valori duplicati in MongoDB, con diversi esempi.\",\"breadcrumb\":{\"@id\":\"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/#breadcrumb\"},\"inLanguage\":\"it-IT\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Casa\",\"item\":\"https:\/\/statorials.org\/it\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Come trovare duplicati in mongodb\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/statorials.org\/it\/#website\",\"url\":\"https:\/\/statorials.org\/it\/\",\"name\":\"Statorials\",\"description\":\"La tua guida all&#039;alfabetizzazione statistica!\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/statorials.org\/it\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"it-IT\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/statorials.org\/it\/#\/schema\/person\/0896f191fb9fb019f2cd8623112cb3ae\",\"name\":\"Benjamin anderson\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"it-IT\",\"@id\":\"https:\/\/statorials.org\/it\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/statorials.org\/it\/wp-content\/uploads\/2023\/10\/Dr.-Benjamin-Anderson-96x96.jpg\",\"contentUrl\":\"https:\/\/statorials.org\/it\/wp-content\/uploads\/2023\/10\/Dr.-Benjamin-Anderson-96x96.jpg\",\"caption\":\"Benjamin anderson\"},\"description\":\"Ciao, sono Benjamin, un professore di statistica in pensione diventato insegnante dedicato di Statorials. Con una vasta esperienza e competenza nel campo della statistica, sono ansioso di condividere le mie conoscenze per potenziare gli studenti attraverso Statorials. Scopri di pi\u00f9\",\"sameAs\":[\"https:\/\/statorials.org\/it\"]}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Come trovare duplicati in MongoDB \u2013 Statorials","description":"Questo tutorial spiega come trovare valori duplicati in MongoDB, con diversi esempi.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/","og_locale":"it_IT","og_type":"article","og_title":"Come trovare duplicati in MongoDB \u2013 Statorials","og_description":"Questo tutorial spiega come trovare valori duplicati in MongoDB, con diversi esempi.","og_url":"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/","og_site_name":"Statorials","article_published_time":"2023-07-22T06:16:57+00:00","author":"Benjamin anderson","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Benjamin anderson","Est. reading time":"1 minuto"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/","url":"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/","name":"Come trovare duplicati in MongoDB \u2013 Statorials","isPartOf":{"@id":"https:\/\/statorials.org\/it\/#website"},"datePublished":"2023-07-22T06:16:57+00:00","dateModified":"2023-07-22T06:16:57+00:00","author":{"@id":"https:\/\/statorials.org\/it\/#\/schema\/person\/0896f191fb9fb019f2cd8623112cb3ae"},"description":"Questo tutorial spiega come trovare valori duplicati in MongoDB, con diversi esempi.","breadcrumb":{"@id":"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/#breadcrumb"},"inLanguage":"it-IT","potentialAction":[{"@type":"ReadAction","target":["https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/statorials.org\/it\/mongodb-trova-duplicati\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Casa","item":"https:\/\/statorials.org\/it\/"},{"@type":"ListItem","position":2,"name":"Come trovare duplicati in mongodb"}]},{"@type":"WebSite","@id":"https:\/\/statorials.org\/it\/#website","url":"https:\/\/statorials.org\/it\/","name":"Statorials","description":"La tua guida all&#039;alfabetizzazione statistica!","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/statorials.org\/it\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"it-IT"},{"@type":"Person","@id":"https:\/\/statorials.org\/it\/#\/schema\/person\/0896f191fb9fb019f2cd8623112cb3ae","name":"Benjamin anderson","image":{"@type":"ImageObject","inLanguage":"it-IT","@id":"https:\/\/statorials.org\/it\/#\/schema\/person\/image\/","url":"https:\/\/statorials.org\/it\/wp-content\/uploads\/2023\/10\/Dr.-Benjamin-Anderson-96x96.jpg","contentUrl":"https:\/\/statorials.org\/it\/wp-content\/uploads\/2023\/10\/Dr.-Benjamin-Anderson-96x96.jpg","caption":"Benjamin anderson"},"description":"Ciao, sono Benjamin, un professore di statistica in pensione diventato insegnante dedicato di Statorials. Con una vasta esperienza e competenza nel campo della statistica, sono ansioso di condividere le mie conoscenze per potenziare gli studenti attraverso Statorials. Scopri di pi\u00f9","sameAs":["https:\/\/statorials.org\/it"]}]}},"yoast_meta":{"yoast_wpseo_title":"","yoast_wpseo_metadesc":"","yoast_wpseo_canonical":""},"_links":{"self":[{"href":"https:\/\/statorials.org\/it\/wp-json\/wp\/v2\/posts\/2445"}],"collection":[{"href":"https:\/\/statorials.org\/it\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/statorials.org\/it\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/statorials.org\/it\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/statorials.org\/it\/wp-json\/wp\/v2\/comments?post=2445"}],"version-history":[{"count":0,"href":"https:\/\/statorials.org\/it\/wp-json\/wp\/v2\/posts\/2445\/revisions"}],"wp:attachment":[{"href":"https:\/\/statorials.org\/it\/wp-json\/wp\/v2\/media?parent=2445"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/statorials.org\/it\/wp-json\/wp\/v2\/categories?post=2445"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/statorials.org\/it\/wp-json\/wp\/v2\/tags?post=2445"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}