{"id":198521,"date":"2023-06-23T07:30:00","date_gmt":"2023-06-23T07:30:00","guid":{"rendered":"https:\/\/datascientest.com\/?p=198521"},"modified":"2023-11-09T13:51:49","modified_gmt":"2023-11-09T13:51:49","slug":"sql-distinct-tout-savoir","status":"publish","type":"post","link":"https:\/\/datascientest.com\/sql-distinct-tout-savoir","title":{"rendered":"SQL DISTINCT : Comment utiliser cette requ\u00eate ?"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"198521\" class=\"elementor elementor-198521\" data-elementor-post-type=\"post\">\n\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-0bab91a e-flex e-con-boxed e-con\" data-id=\"0bab91a\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-f03122e elementor-widget elementor-widget-heading\" data-id=\"f03122e\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.15.0 - 02-08-2023 *\/\n.elementor-heading-title{padding:0;margin:0;line-height:1}.elementor-widget-heading .elementor-heading-title[class*=elementor-size-]>a{color:inherit;font-size:inherit;line-height:inherit}.elementor-widget-heading .elementor-heading-title.elementor-size-small{font-size:15px}.elementor-widget-heading .elementor-heading-title.elementor-size-medium{font-size:19px}.elementor-widget-heading .elementor-heading-title.elementor-size-large{font-size:29px}.elementor-widget-heading .elementor-heading-title.elementor-size-xl{font-size:39px}.elementor-widget-heading .elementor-heading-title.elementor-size-xxl{font-size:59px}<\/style><h2 class=\"elementor-heading-title elementor-size-default\">Si la commande SELECT est l\u2019une des plus couramment utilis\u00e9es pour lire les donn\u00e9es d\u2019un tableau, elle pr\u00e9sente quelques lacunes si elle est utilis\u00e9e toute seule. C\u2019est pourquoi, d\u2019autres commandes lui sont associ\u00e9es. Ces combinaisons permettent ainsi d\u2019affiner les r\u00e9sultats. Et notamment la commande SQL DISTINCT qui supprime les doublons au sein d\u2019une Base de Donn\u00e9e MySQL.<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-4a32f0f e-flex e-con-boxed e-con\" data-id=\"4a32f0f\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-df1c27f elementor-widget elementor-widget-heading\" data-id=\"df1c27f\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Qu'est ce que SQL DISTINCT ?<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4562fb1 elementor-widget elementor-widget-text-editor\" data-id=\"4562fb1\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.15.0 - 02-08-2023 *\/\n.elementor-widget-text-editor.elementor-drop-cap-view-stacked .elementor-drop-cap{background-color:#69727d;color:#fff}.elementor-widget-text-editor.elementor-drop-cap-view-framed .elementor-drop-cap{color:#69727d;border:3px solid;background-color:transparent}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap{margin-top:8px}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap-letter{width:1em;height:1em}.elementor-widget-text-editor .elementor-drop-cap{float:left;text-align:center;line-height:1;font-size:50px}.elementor-widget-text-editor .elementor-drop-cap-letter{display:inline-block}<\/style>\t\t\t\t<p><span style=\"font-weight: 400;\">La requ\u00eate SQL DISTINCT permet de<\/span><b> limiter les doublons<\/b><span style=\"font-weight: 400;\">. En effet, lorsque vous utilisez la commande d\u2019instruction SELECT, vous pouvez s\u00e9lectionner une ou plusieurs colonnes de la table. Mais \u00e0 l\u2019int\u00e9rieur de ces colonnes, il peut y avoir des lignes en double. Pour \u00e9viter cela, vous devez ajouter DISTINCT \u00e0 la requ\u00eate SELECT. Ce faisant, <\/span><b>toutes les redondances sont \u00e9limin\u00e9es.\u00a0<\/b><\/p><p><span style=\"font-weight: 400;\">Concr\u00e8tement, cette commande se pr\u00e9sente comme suit :\u00a0<\/span><\/p><p style=\"padding-left: 40px;\"><strong>SELECT DISTINCT nom_de_la_colonne<\/strong><\/p><p style=\"padding-left: 40px;\"><strong>FROM nom_du_tableau<\/strong><\/p><p><span style=\"font-weight: 400;\">Vous pouvez utiliser cette commande sur une seule colonne ou sur un ensemble de colonnes li\u00e9es.\u00a0<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5734ce0 elementor-widget elementor-widget-text-editor\" data-id=\"5734ce0\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><strong>Bon \u00e0 savoir <\/strong><span style=\"font-weight: 400;\">: si vous utilisez un syst\u00e8me de gestion de base de donn\u00e9es Oracle, il ne faudra pas utiliser la commande SQL DISTINCT, mais la commande UNIQUE.\u00a0<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-68fc588 e-flex e-con-boxed e-con\" data-id=\"68fc588\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-94aca62 elementor-widget elementor-widget-heading\" data-id=\"94aca62\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">3 exemples d\u2019utilisation de SQL DISTINCT<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-66130ef elementor-widget elementor-widget-text-editor\" data-id=\"66130ef\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Pour vous aider \u00e0 mieux comprendre comment utiliser la requ\u00eate SQL DISTINCT, voici 3\u00a0 exemples d\u2019application concrets.\u00a0 <\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8e45ef5 elementor-widget elementor-widget-heading\" data-id=\"8e45ef5\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">La requ\u00eate SELECT DISTINCT pour une colonne unique<\/h4>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-02dfec8 elementor-widget elementor-widget-text-editor\" data-id=\"02dfec8\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">C\u2019est l&rsquo;<\/span><b>utilisation basique<\/b><span style=\"font-weight: 400;\"> de la requ\u00eate SQL DISTINCT.\u00a0<\/span><\/p><p><span style=\"font-weight: 400;\">Dans notre exemple, vous disposez d\u2019un tableau avec l\u2019int\u00e9gralit\u00e9 de vos clients, dont plusieurs appartiennent \u00e0 la m\u00eame famille (nom de famille identique).<\/span><\/p><p><span style=\"font-weight: 400;\">Voici votre tableau :<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-29f4cb0 elementor-widget elementor-widget-html\" data-id=\"29f4cb0\" data-element_type=\"widget\" data-widget_type=\"html.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style type=\"text\/css\">\r\n.tg  {border-collapse:collapse;border-spacing:0;}\r\n.tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\r\n  overflow:hidden;padding:10px 5px;word-break:normal;}\r\n.tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\r\n  font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;}\r\n.tg .tg-baqh{text-align:center;vertical-align:top}\r\n.tg .tg-9ix1{background-color:#6434fc;color:#efefef;font-size:20px;font-weight:bold;text-align:center;vertical-align:top}\r\n<\/style>\r\n<table class=\"tg\" style=\"undefined;table-layout: fixed; width: 300px\">\r\n<colgroup>\r\n<col style=\"width: 50px\">\r\n<col style=\"width: 125px\">\r\n<col style=\"width: 125px\">\r\n<\/colgroup>\r\n<thead>\r\n  <tr>\r\n    <th class=\"tg-9ix1\">ID<\/th>\r\n    <th class=\"tg-9ix1\">Pr\u00e9nom<\/th>\r\n    <th class=\"tg-9ix1\">Nom<\/th>\r\n  <\/tr>\r\n<\/thead>\r\n<tbody>\r\n  <tr>\r\n    <td class=\"tg-9ix1\">1<\/td>\r\n    <td class=\"tg-baqh\">Pierre<\/td>\r\n    <td class=\"tg-baqh\">Dupont<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-9ix1\">2<\/td>\r\n    <td class=\"tg-baqh\">Jeanne<\/td>\r\n    <td class=\"tg-baqh\">Martin<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-9ix1\">3<\/td>\r\n    <td class=\"tg-baqh\">Henri<\/td>\r\n    <td class=\"tg-baqh\">Durand<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-9ix1\">4<\/td>\r\n    <td class=\"tg-baqh\">Bertrand<\/td>\r\n    <td class=\"tg-baqh\">Petit<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-9ix1\">5<\/td>\r\n    <td class=\"tg-baqh\">Martine<\/td>\r\n    <td class=\"tg-baqh\">Dupont<\/td>\r\n  <\/tr>\r\n<\/tbody>\r\n<\/table>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1d29d6f elementor-widget elementor-widget-text-editor\" data-id=\"1d29d6f\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Si vous souhaitez afficher seulement les familles uniques, voici la requ\u00eate \u00e0 utiliser : <strong>SELECT DISTINCT nom FROM client<\/strong>.\u00a0<\/span><\/p><p><span style=\"font-weight: 400;\">Et voici le r\u00e9sultat :\u00a0<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ffc60e7 elementor-widget elementor-widget-html\" data-id=\"ffc60e7\" data-element_type=\"widget\" data-widget_type=\"html.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style type=\"text\/css\">\r\n.tg  {border-collapse:collapse;border-spacing:0;}\r\n.tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\r\n  overflow:hidden;padding:10px 5px;word-break:normal;}\r\n.tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\r\n  font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;}\r\n.tg .tg-5t56{background-color:#6434fc;color:#efefef;font-size:20px;text-align:center;vertical-align:top}\r\n.tg .tg-lap0{font-size:100%;text-align:center;vertical-align:top}\r\n<\/style>\r\n<table class=\"tg\" style=\"undefined;table-layout: fixed; width: 74px\">\r\n<colgroup>\r\n<col style=\"width: 100px\">\r\n<\/colgroup>\r\n<thead>\r\n  <tr>\r\n    <th class=\"tg-5t56\">Nom<\/th>\r\n  <\/tr>\r\n<\/thead>\r\n<tbody>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Dupont<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Martin<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Durand<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Petit<\/td>\r\n  <\/tr>\r\n<\/tbody>\r\n<\/table>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2fcc6d5 elementor-widget elementor-widget-text-editor\" data-id=\"2fcc6d5\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Ici, le nom Dupond n\u2019est affich\u00e9 qu\u2019une seule fois (contre deux fois dans le premier tableau). <\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6e1ffed elementor-align-center button-principale elementor-widget elementor-widget-button\" data-id=\"6e1ffed\" data-element_type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm elementor-animation-grow\" href=\"https:\/\/datascientest.com\/formation-sql\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t<span class=\"elementor-button-text\">Apprendre SQL pour la Data Science<\/span>\n\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2798304 elementor-widget elementor-widget-heading\" data-id=\"2798304\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">La requ\u00eate SELECT DISTINCT pour plusieurs colonnes<\/h4>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b28198b elementor-widget elementor-widget-text-editor\" data-id=\"b28198b\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Comme mentionn\u00e9 pr\u00e9c\u00e9demment, la commande DISTINCT peut aussi \u00eatre utilis\u00e9e pour plusieurs colonnes.\u00a0<\/span><\/p><p><span style=\"font-weight: 400;\">Reprenons un exemple de table Client similaire :<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fc3a428 elementor-widget elementor-widget-html\" data-id=\"fc3a428\" data-element_type=\"widget\" data-widget_type=\"html.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style type=\"text\/css\">\r\n.tg  {border-collapse:collapse;border-spacing:0;}\r\n.tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\r\n  overflow:hidden;padding:10px 5px;word-break:normal;}\r\n.tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\r\n  font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;}\r\n.tg .tg-5t56{background-color:#6434fc;color:#efefef;font-size:20px;text-align:center;vertical-align:top}\r\n.tg .tg-baqh{text-align:center;vertical-align:top}\r\n.tg .tg-mw77{background-color:#6434fc;color:#efefef;text-align:center;vertical-align:top}\r\n<\/style>\r\n<table class=\"tg\" style=\"undefined;table-layout: fixed; width: 300px\">\r\n<colgroup>\r\n<col style=\"width: 50px\">\r\n<col style=\"width: 125px\">\r\n<col style=\"width: 125px\">\r\n<\/colgroup>\r\n<thead>\r\n  <tr>\r\n    <th class=\"tg-mw77\">ID<\/th>\r\n    <th class=\"tg-5t56\">Pr\u00e9nom<\/th>\r\n    <th class=\"tg-5t56\">Nom<\/th>\r\n  <\/tr>\r\n<\/thead>\r\n<tbody>\r\n  <tr>\r\n    <td class=\"tg-5t56\">1<\/td>\r\n    <td class=\"tg-baqh\">Martine<\/td>\r\n    <td class=\"tg-baqh\">Dupont<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-5t56\">2<\/td>\r\n    <td class=\"tg-baqh\">Jeanne<\/td>\r\n    <td class=\"tg-baqh\">Martin<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-5t56\">3<\/td>\r\n    <td class=\"tg-baqh\">Henry<\/td>\r\n    <td class=\"tg-baqh\">Durand<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-5t56\">4<\/td>\r\n    <td class=\"tg-baqh\">Bertrand<\/td>\r\n    <td class=\"tg-baqh\">Petit<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-5t56\">5<\/td>\r\n    <td class=\"tg-baqh\">Martine<\/td>\r\n    <td class=\"tg-baqh\">Dupont<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-5t56\">6<\/td>\r\n    <td class=\"tg-baqh\">Antoine<\/td>\r\n    <td class=\"tg-baqh\">Martin<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-5t56\">7<\/td>\r\n    <td class=\"tg-baqh\">Fabienne<\/td>\r\n    <td class=\"tg-baqh\">Bernard<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-5t56\">8<\/td>\r\n    <td class=\"tg-baqh\">Christelle<\/td>\r\n    <td class=\"tg-baqh\">Robert<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-5t56\">9<\/td>\r\n    <td class=\"tg-baqh\">Henri<\/td>\r\n    <td class=\"tg-baqh\">Durand<\/td>\r\n  <\/tr>\r\n<\/tbody>\r\n<\/table>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-482afef elementor-widget elementor-widget-text-editor\" data-id=\"482afef\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Si vous souhaitez afficher seulement les familles uniques, voici la requ\u00eate \u00e0 utiliser : <strong>SELECT DISTINCT pr\u00e9nom nom FROM client<\/strong>.\u00a0<\/span><\/p><p><span style=\"font-weight: 400;\">Et voici le r\u00e9sultat : <\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1342a44 elementor-widget elementor-widget-html\" data-id=\"1342a44\" data-element_type=\"widget\" data-widget_type=\"html.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style type=\"text\/css\">\r\n.tg  {border-collapse:collapse;border-spacing:0;}\r\n.tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\r\n  overflow:hidden;padding:10px 5px;word-break:normal;}\r\n.tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px;\r\n  font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;}\r\n.tg .tg-5t56{background-color:#6434fc;color:#efefef;font-size:20px;text-align:center;vertical-align:top}\r\n.tg .tg-baqh{text-align:center;vertical-align:top}\r\n.tg .tg-lap0{font-size:100%;text-align:center;vertical-align:top}\r\n<\/style>\r\n<table class=\"tg\" style=\"undefined;table-layout: fixed; width: 250px\">\r\n<colgroup>\r\n<col style=\"width: 125px\">\r\n<col style=\"width: 125px\">\r\n<\/colgroup>\r\n<thead>\r\n  <tr>\r\n    <th class=\"tg-5t56\">Pr\u00e9nom<\/th>\r\n    <th class=\"tg-5t56\">Nom<\/th>\r\n  <\/tr>\r\n<\/thead>\r\n<tbody>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Martine<\/td>\r\n    <td class=\"tg-baqh\">Dupon<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Jeanne<\/td>\r\n    <td class=\"tg-baqh\">Martin<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Henri<\/td>\r\n    <td class=\"tg-baqh\">Durand<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Bertrand<\/td>\r\n    <td class=\"tg-baqh\">Petit<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Antoine<\/td>\r\n    <td class=\"tg-baqh\">Martin<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Fabienne<\/td>\r\n    <td class=\"tg-baqh\">Bernard<\/td>\r\n  <\/tr>\r\n  <tr>\r\n    <td class=\"tg-lap0\">Christelle<\/td>\r\n    <td class=\"tg-baqh\">Robert<\/td>\r\n  <\/tr>\r\n<\/tbody>\r\n<\/table>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fab2d30 elementor-widget elementor-widget-text-editor\" data-id=\"fab2d30\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Dans ce cas, les lignes Martine Dupont et Henry Durand ont \u00e9t\u00e9 \u00e9limin\u00e9es. <\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-16a0f42 elementor-widget elementor-widget-heading\" data-id=\"16a0f42\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Le nombre de valeurs uniques<\/h4>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d0d7c5a elementor-widget elementor-widget-text-editor\" data-id=\"d0d7c5a\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Si vous souhaitez savoir combien de valeur unique comporte votre tableau, il suffit de r\u00e9aliser la manipulation suivante :\u00a0<\/span><\/p><p style=\"padding-left: 40px;\"><b>SELECT COUNT(DISTINCT nom) AS Nombre FROM Client<\/b><\/p><p><span style=\"font-weight: 400;\">Le plus souvent, la requ\u00eate SQL DISTINCT est utilis\u00e9e avec la <a href=\"https:\/\/datascientest.com\/count-sql-tout-savoir\">commande COUNT<\/a> <\/span><span style=\"font-weight: 400;\">pour compter des valeurs. Mais il est possible d\u2019ajouter d\u2019autres agr\u00e9gations en fonction de vos besoins. Cela vous permettra de r\u00e9aliser diff\u00e9rentes op\u00e9rations math\u00e9matiques ou statistiques, sans prendre en compte les doublons. <\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-d914836 e-flex e-con-boxed e-con\" data-id=\"d914836\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-31445d3 elementor-widget elementor-widget-heading\" data-id=\"31445d3\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Les alternatives \u00e0 SQL DISTINCT<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4e0316f elementor-widget elementor-widget-text-editor\" data-id=\"4e0316f\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Pour \u00e9liminer les doublons, il est possible d\u2019utiliser d\u2019autres commandes. Et notamment <\/span><b>GROUP BY \/ ORDER BY.\u00a0<\/b><\/p><p><span style=\"font-weight: 400;\">Dans ce cadre, la requ\u00eate est la suivante :\u00a0<\/span><\/p><p style=\"padding-left: 40px;\"><strong>SELECT nom, Prenom FROM `Client` GROUP BY nom, Prenom ORDER BY nom, Prenom<\/strong><\/p><p><span style=\"font-weight: 400;\">Le r\u00e9sultat est exactement le m\u00eame qu\u2019avec la requ\u00eate : <strong>SELECT DISTINCT pr\u00e9nom nom FROM client<\/strong>. <\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-b10b35f e-flex e-con-boxed e-con\" data-id=\"b10b35f\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-0824b81 elementor-widget elementor-widget-heading\" data-id=\"0824b81\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Maitrisez le langage SQL avec DataScientest<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-315bcbc elementor-widget elementor-widget-text-editor\" data-id=\"315bcbc\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Le <a href=\"https:\/\/datascientest.com\/sql-tout-savoir\">langage de programmation SQL<\/a><\/span>\u00a0<span style=\"font-weight: 400;\">regorge de requ\u00eates indispensables pour manipuler les donn\u00e9es. Si vous souhaitez approfondir vos connaissances en la mati\u00e8re, n\u2019h\u00e9sitez pas \u00e0 rejoindre nos formations chez Datascientest. Orient\u00e9es m\u00e9tiers, ces formations vous permettent d\u2019\u00eatre 100 % op\u00e9rationnel \u00e0 la fin du cursus.<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e65ba32 elementor-align-center button-principale elementor-widget elementor-widget-button\" data-id=\"e65ba32\" data-element_type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm elementor-animation-grow\" href=\"https:\/\/datascientest.com\/formation-sql\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t<span class=\"elementor-button-text\">Devenir expert sur SQL <\/span>\n\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-2e6306a e-flex e-con-boxed e-con\" data-id=\"2e6306a\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-90ff699 elementor-widget elementor-widget-html\" data-id=\"90ff699\" data-element_type=\"widget\" data-widget_type=\"html.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<script type=\"application\/ld+json\">\r\n{\r\n  \"@context\": \"https:\/\/schema.org\",\r\n  \"@type\": \"FAQPage\",\r\n  \"mainEntity\": [{\r\n    \"@type\": \"Question\",\r\n    \"name\": \"SQL DISTINCT pour \u00e9liminer les doublons\",\r\n    \"acceptedAnswer\": {\r\n      \"@type\": \"Answer\",\r\n      \"text\": \"La requ\u00eate SQL DISTINCT permet de limiter les doublons. En effet, lorsque vous utilisez la commande d\u2019instruction SELECT, vous pouvez s\u00e9lectionner une ou plusieurs colonnes de la table. Mais \u00e0 l\u2019int\u00e9rieur de ces colonnes, il peut y avoir des lignes en double. Pour \u00e9viter cela, vous devez ajouter DISTINCT \u00e0 la requ\u00eate SELECT. Ce faisant, toutes les redondances sont \u00e9limin\u00e9es.\"\r\n    }\r\n  },{\r\n    \"@type\": \"Question\",\r\n    \"name\": \"Les alternatives \u00e0 SQL DISTINCT\",\r\n    \"acceptedAnswer\": {\r\n      \"@type\": \"Answer\",\r\n      \"text\": \"Pour \u00e9liminer les doublons, il est possible d\u2019utiliser d\u2019autres commandes. Et notamment GROUP BY \/ ORDER BY.\"\r\n    }\r\n  }]\r\n}\r\n<\/script>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Si la commande SELECT est l\u2019une des plus couramment utilis\u00e9es pour lire les donn\u00e9es d\u2019un tableau, elle pr\u00e9sente quelques lacunes si elle est utilis\u00e9e toute seule. C\u2019est pourquoi, d\u2019autres commandes lui sont associ\u00e9es. Ces combinaisons permettent ainsi d\u2019affiner les r\u00e9sultats. Et notamment la commande SQL DISTINCT qui supprime les doublons au sein d\u2019une Base de [&hellip;]<\/p>\n","protected":false},"author":77,"featured_media":198523,"comment_status":"open","ping_status":"open","sticky":false,"template":"elementor_theme","format":"standard","meta":{"content-type":"","inline_featured_image":false},"categories":[2497],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.7 (Yoast SEO v21.7) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>SQL DISTINCT : Comment utiliser cette requ\u00eate ?<\/title>\n<meta name=\"description\" content=\"Afin d\u2019\u00e9viter les doublons au sein de votre base de donn\u00e9es, il y a la requ\u00eate SQL DISTINCT. Focus.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/datascientest.com\/sql-distinct-tout-savoir\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"SQL DISTINCT : Comment utiliser cette requ\u00eate ?\" \/>\n<meta property=\"og:url\" content=\"https:\/\/datascientest.com\/sql-distinct-tout-savoir\" \/>\n<meta property=\"og:site_name\" content=\"Formation Data Science | DataScientest.com\" \/>\n<meta property=\"article:published_time\" content=\"2023-06-23T07:30:00+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-11-09T13:51:49+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/datascientest.com\/wp-content\/uploads\/2023\/04\/SQL_DISTINCT_DATASCIENTEST.png\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"600\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"Raphael Kassel\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u00c9crit par\" \/>\n\t<meta name=\"twitter:data1\" content=\"Raphael Kassel\" \/>\n\t<meta name=\"twitter:label2\" content=\"Dur\u00e9e de lecture estim\u00e9e\" \/>\n\t<meta name=\"twitter:data2\" content=\"4 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/datascientest.com\/sql-distinct-tout-savoir\",\"url\":\"https:\/\/datascientest.com\/sql-distinct-tout-savoir\",\"name\":\"SQL DISTINCT : Comment utiliser cette requ\u00eate ?\",\"isPartOf\":{\"@id\":\"https:\/\/datascientest.com\/#website\"},\"datePublished\":\"2023-06-23T07:30:00+00:00\",\"dateModified\":\"2023-11-09T13:51:49+00:00\",\"author\":{\"@id\":\"https:\/\/datascientest.com\/#\/schema\/person\/6eca16f63daaafcbc96e15549b9d4ee1\"},\"description\":\"Afin d\u2019\u00e9viter les doublons au sein de votre base de donn\u00e9es, il y a la requ\u00eate SQL DISTINCT. 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