Summary\/strong>: in this tutorial, you will learn how to use the PostgreSQL LEFT JOIN\/code> clause to select data from multiple tables.\/p>\n\n\n\n

The <code>AS<\/code> keyword is optional so you can omit it like this:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-2\" data-shcb-language …

Summary\/strong>: in this tutorial, you will learn how to use PostgreSQL indexes to enhance the data retrieval speed and various index types.\/p>\n\n\n\n

In PostgreSQL, a foreign key is a column or a group of columns in a table that uniquely identifies a row in another table\/strong>.\/p>\n\n\n\n