how to use sql
free sql guide
SQL is pronounced SEQUEL and stands for Structured Query Language. SQL belongs to the family of database management languages. It is the most important language in database programming. This language allows you to:
create and modify database schemas ;
Insert, modify and manage the stored data ;
Query the stored data ;
create and manage control tools ;
access to all the data mentioned above ;
Here is a basic guide for programming with the SQL language . This guide is a simple SQL course with many examples.
SQL Guide: the basics to start programming databases from ANDREA BARBIERI
It is understood that SQL is not only a query language , but also has database management and control functions typical of other programming languages .
In fact, SQL has all the features of programming language.
Before arriving at this language it was necessary to identify a mathematical model that would relate all the components of a database.
The database is a structured data archive that allows you to manage the data in a practical way. All this allows the updating of information (insert new data, delete data or search for data). This model was developed
was developed in the 70s by the computer scientist Edgar F. Cood and is called RDBMS ( Relational Database Management System )
Edgar F Codd
Edgar F Codd
This type of system is managed through various applications. I provide you with links to free applications that will allow you to create and program a database:
SQL Server Express ,
SQL Server Management Studio ,
They all have a similar interface. All the tools I have shown you represent relational databases
The minimum requirements for the RBDMS system are:
must present data to the user in the form of relationships (a table presentation can satisfy this property)
must provide relational operators to manipulate the data in a tabular form.
What are sitelinks
The links displayed below the search results are called sitelinks. And they aim to improve the navigation of the readers of the website. Sitelinks are links related to a website. Which Google shows very relevant to the result displayed based on a particular search (query) Sitelinks point to pages or categories of the website. That search engines consider the main pillar of the domain shown in the SERP. And they are generated automatically by the search engine algorithms. But how do sitelinks appear?
They are shown on the Google search bar . associated with the relative snippet from a specific search result and a given keyword. They usually appear for brand research. They tend to be shown in pairs (but not always) with the keyword and brand name. This is the sitelink of this site chosen by Google when I am writing the article.
Siteliniks are important for improving the user experience. The purpose of this article is to understand how to get sitelinks on Google . Sitelinks are located under the brand name. Each pair of sitelinks shows one less result (of the 10 proposed by the SERP). For this reason, in some cases, the first page of the search shows few results. In addition to those of the domain searched.
Sitelinks I don’t know appear only for a company brand search. But also for generic keywords . Before even telling you how it is possible to have them, I will tell you right away that it is not possible to insert or remove them automatically . It is the search engine that decides which type of sitelink is useful to the user. But if your website is unable to obtain sitelinks, it is possible to work on some aspects of the site which increase the probability that search engines insert sitelinks under the brand name.
About 10 years ago it was possible to remove sitelinks. this option was removed in 2016. WhenGoogle Search Console
Google Search Console is the free tool to monitor …
it was called Google Webmaster Tools . Let’s see the steps necessary to have sitelinks. In the next paragraphs the methods that allow you to get them. I prepared this infographic that summarizes them.