{"id":1574,"date":"2023-05-02T14:15:20","date_gmt":"2023-05-02T14:15:20","guid":{"rendered":"http:\/\/localhost\/codeera\/?p=1574"},"modified":"2023-05-02T15:00:18","modified_gmt":"2023-05-02T15:00:18","slug":"introduction-to-sql-joins-inner-outer-left-right-and-cross","status":"publish","type":"post","link":"http:\/\/localhost\/codeera\/2023\/05\/02\/introduction-to-sql-joins-inner-outer-left-right-and-cross\/","title":{"rendered":"Introduction to SQL Joins: Inner, Outer, Left, Right, and Cross"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"1574\" class=\"elementor elementor-1574\">\n\t\t\t\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-3e7eaa0 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"3e7eaa0\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-c61d1a1\" data-id=\"c61d1a1\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-7cd4f30 elementor-widget elementor-widget-text-editor\" data-id=\"7cd4f30\" 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 - v3.11.1 - 15-02-2023 *\/\n.elementor-widget-text-editor.elementor-drop-cap-view-stacked .elementor-drop-cap{background-color:#818a91;color:#fff}.elementor-widget-text-editor.elementor-drop-cap-view-framed .elementor-drop-cap{color:#818a91;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><!-- wp:list {\"ordered\":true} --><\/p><ol><li style=\"list-style-type: none;\"><ol><!-- wp:list-item --><\/ol><\/li><\/ol><p><b>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<\/b><\/p><h4>Introduction to SQL Joins:<\/h4><p>SQL Joins are used to combine data from multiple tables into a single result set. There are five types of SQL joins: Inner, Outer, Left, Right, and Cross.<\/p><h4><b>1. Inner Join<\/b>:<\/h4><p>An Inner Join returns only the rows that have matching values in both tables being joined.<\/p><p>The syntax of an Inner Join is:<\/p><pre class=\"wp-block-preformatted\"><code><b><span class=\"hljs-keyword\">SELECT<\/span> <span class=\"hljs-keyword\">column<\/span>(s) <span class=\"hljs-keyword\">FROM<\/span> table1 <span class=\"hljs-keyword\">INNER<\/span> <span class=\"hljs-keyword\">JOIN<\/span> table2 <span class=\"hljs-keyword\">ON<\/span> table1.column <span class=\"hljs-operator\">=<\/span> table2.column;<\/b>\n<\/code><\/pre><p>Here, <code>table1<\/code> and <code>table2<\/code> are the tables being joined, <code>column<\/code> is the column on which the join is based, and <code>column(s)<\/code> are the columns being selected.<\/p><h4><strong>2. Left Join<\/strong>:<\/h4><p>A Left Join returns all the rows from the left table and the matching rows from the right table. If there are no matching rows in the right table, then NULL values are returned.<\/p><p>The syntax of a Left Join is:<\/p><p><!-- \/wp:paragraph --><!-- wp:preformatted --><\/p><pre class=\"wp-block-preformatted\"><code><b>     <span class=\"hljs-keyword\">SELECT<\/span> <span class=\"hljs-keyword\">column<\/span>(s) <span class=\"hljs-keyword\">FROM<\/span> table1 <span class=\"hljs-keyword\">LEFT<\/span> <span class=\"hljs-keyword\">JOIN<\/span> table2 <span class=\"hljs-keyword\">ON<\/span> table1.column <span class=\"hljs-operator\">=<\/span> table2.column;<\/b><\/code><\/pre><p>Here, <code>table1<\/code> is the left table, <code>table2<\/code> is the right table, <code>column<\/code> is the column on which the join is based, and <code>column(s)<\/code> are the columns being selected.<\/p><h4><strong>3. Right Join:<br \/><\/strong><\/h4><p>A Right Join returns all the rows from the right table and the matching rows from the left table. If there are no matching rows in the left table, then NULL values are returned.<\/p><p>The syntax of a Right Join is:<\/p><pre class=\"wp-block-preformatted\"><code><b>     <span class=\"hljs-keyword\">SELECT<\/span> <span class=\"hljs-keyword\">column<\/span>(s) <span class=\"hljs-keyword\">FROM<\/span> table1 <span class=\"hljs-keyword\">RIGHT<\/span> <span class=\"hljs-keyword\">JOIN<\/span> table2 <span class=\"hljs-keyword\">ON<\/span> table1.column <span class=\"hljs-operator\">=<\/span> table2.column;<\/b><\/code><\/pre><p>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Here, <code>table1<\/code> is the left table, <code>table2<\/code> is the right table, <code>column<\/code> is the column on which the join is based, and <code>column(s)<\/code> are the columns being selected.<\/p><h4><strong>4. Full Outer Join:<\/strong><\/h4><p>A Full Outer Join returns all the rows from both tables, along with NULL values where there are no matches.<\/p><p>The syntax of a Full Outer Join is:<\/p><pre class=\"wp-block-preformatted\"><code><b>    <span class=\"hljs-keyword\">SELECT<\/span> <span class=\"hljs-keyword\">column<\/span>(s) <span class=\"hljs-keyword\">FROM<\/span> table1 <span class=\"hljs-keyword\">FULL<\/span> <span class=\"hljs-keyword\">OUTER<\/span> <span class=\"hljs-keyword\">JOIN<\/span> table2 <span class=\"hljs-keyword\">ON<\/span> table1.column <span class=\"hljs-operator\">=<\/span> table2.column;<\/b><\/code><\/pre><p>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Here, <code>table1<\/code> is the left table, <code>table2<\/code> is the right table, <code>column<\/code> is the column on which the join is based, and <code>column(s)<\/code> are the columns being selected.<\/p><h4><strong>5. Cross Join:<\/strong><\/h4><p>A Cross Join returns the Cartesian product of the two tables being joined, i.e., all possible combinations of rows from both tables.<\/p><p>The syntax of a Cross Join is:<\/p><pre class=\"wp-block-preformatted\"><code><b>   <span class=\"hljs-keyword\">SELECT<\/span> <span class=\"hljs-keyword\">column<\/span>(s) <span class=\"hljs-keyword\">FROM<\/span> table1 <span class=\"hljs-keyword\">CROSS<\/span> <span class=\"hljs-keyword\">JOIN<\/span> table2;<\/b><\/code><\/pre><p>Here, <code>table1<\/code> and <code>table2<\/code> are the tables being joined, and <code>column(s)<\/code> are the columns being selected.<\/p><p>Joins are a powerful tool in SQL, allowing you to combine data from multiple tables into a single result set. Understanding the different types of joins and their syntax is an essential part of working with databases.\u00a0<\/p><p><!-- \/wp:paragraph --><!-- wp:paragraph --><\/p><p><!-- \/wp:paragraph --><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-global-header-display":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/posts\/1574"}],"collection":[{"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/comments?post=1574"}],"version-history":[{"count":28,"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/posts\/1574\/revisions"}],"predecessor-version":[{"id":1608,"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/posts\/1574\/revisions\/1608"}],"wp:attachment":[{"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/media?parent=1574"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/categories?post=1574"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/localhost\/codeera\/wp-json\/wp\/v2\/tags?post=1574"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}