For an instructor lead, in-depth look at learning SQL click below.
Introduction
Structured Query Language or SQL is a standard Database language which is used to create, maintain and retrieve the data from relational databases like MySQL, Oracle, SQL Server, PostGre, etc. The simple and easy-to-understand syntax makes it a powerful tool for managing and manipulating relational databases. In this blog post, we are going to introduce some fundamental concepts and commands of SQL that every beginner must learn. As the proverb says, every long journey starts with the first step, here is our first step into the world of SQL.
SQL Basics
The SQL language is straightforward. You don’t need a computer science degree to be proficient. It mostly consists of English language words, which makes it easy to understand. For instance, here is an example of a basic SQL ‘SELECT’ statement:
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SELECT * FROM Employees; |
This code basically says, “select (or return) everything from the table named ‘Employees'”. Isn’t that simple? Now, let’s dive a bit deeper.
SELECT Statement
The SELECT statement is used to select data from a database. The data returned is stored in a result table, called the result-set. Here’s another example in which we’re selecting a single column ‘Name’ from the ‘Employees’ table:
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SELECT Name FROM Employees; |
Distinct Keyword
If you want to select all the unique names from the ‘Employees’ table, we will use the DISTINCT keyword as follows:
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SELECT DISTINCT Name FROM Employees; |
WHERE Clause
The WHERE clause is used to filter records. It is used to extract only those records that fulfill a specified condition. For instance, let’s extract the information of employees whose age is more than 30:
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SELECT * FROM Employees WHERE Age > 30; |
Conclusion
These are just the basics of what SQL can do. The more you practice and use these statements, the more comfortable you’ll get with the SQL syntax. SQL is a powerful language that’s worth the effort to learn. I hope this SQL Starter Kit for Beginners has been helpful to you as you start your journey. Happy querying!