Using Sql To Insert And Retrieve Data
Using Sql to insert and retrieve data

it is quite tricky and tiresome when starting to learn Sql but as you continue to study and be able to insert and retrieve data it is enjoyable to my experience  So, now you know what SQL is, you might be wondering what it is used for. As we mentioned earlier, it is a programming language used to communicate with relational databases. But let’s explore that a little further. 

SQL allows you to query the database in a variety of ways, using English-like statements (we discussed some examples earlier). It is used on websites for back-end data storage and data processing solutions (Facebook is a site that uses this).

Other than Facebook, you can expect SQL to be used within music apps like spotify, banking apps like Revolut and other social media platforms such as Twitter and Instagram. SQL is the most commonly used database language, and so it can be used for almost any company that needs to store relational data.

Queries within SQL are used to retrieve data from the database, but the queries vary in efficiency. This is due to the fact that many databases have their own system-specific additional proprietary extensions.

Essentially, SQL provides CRUD functionality for databases. What does CRUD stand for?

  • Create
  • Read
  • Update
  • Delete

Types of SQL commands

The language can be broken down into four types of SQL commands – DDL, DML, DQL and DCL. Let’s look at what each of these sections are:

  • DDL (data definition language) – this is used to create and modify database objects like tables, users, and indices.
  • DML (data manipulation language) – this is used to delete, add, and modify data within databases.
  • DCL (data control language) – this is used to control access to any data within a database.
  • DQL (data query language) – this is used to perform queries on the data and find information, and is composed of COMMAND statements only.

There are tools available to help you write SQL, some of these tools include Microsoft’s SQL Server Management Studio, DataGrip, Oracle’s SQL developer, SQL Workbench and Toad.

SQL vs NoSQL

NoSQL databases came to prominence in the late 2000s in order to accommodate data with less need for upfront structure. These types of databases tend to be  easier for developers, can sometimes have faster queries and more flexible data models.

In comparison, SQL based databases are used specifically for relational data. They allow for flexible query use, are well structured and have a reduced data storage footprint. SQL databases are far more common than NoSQL, but frequently they are used together.

There are some major differences between the two, these include:

  • Scalability – NoSQL databases tend to be horizontally scalable, whereas SQL databases are more often vertically scalable. This means that NoSQL databases can often handle higher traffic numbers.
  • Structure – SQL databases have a table-based structure, but NoSQL databases can be graph-based, document-based or wide column stores. SQL databases are better suited for multi-row transactions.
  • Knowledge and community – There is a huge range of information and communities available for SQL since it is more common and has been around for longer. NoSQL does not share this number of forums and resources, so it may be harder to seek help when needed

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Author(s):

  • Matthew Njuguna Maina