For an instructor lead, in-depth look at learning SQL click below.
Welcome to SQL 101, your introductory course on the Structured Query Language (SQL), a type of programming language that helps you access, manipulate, and analyse data stored in relational databases.
What is SQL?
SQL stands for Structured Query Language. It’s a standard language for communicating with relational databases. It allows you to access, manipulate, and analyze data. Whether you need to retrieve a single record or perform complex analytics on a group of datasets, SQL gives you the power to get the job done.
Getting Started With SQL
To get started with SQL, you need to establish a connection to a database. For our examples, we will use a simple Students database.
SQL SELECT Statement
Let’s say we want to see all the information in the Students database. We use the SELECT statement for this purpose. The asterisk (*) means “all.”
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SELECT * FROM Students; |
SQL WHERE Clause
If we’re specifically interested in students who are studying Computer Science, we could modify our SELECT statement to use a WHERE clause:
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SELECT * FROM Students WHERE Major = 'Computer Science'; |
SQL JOIN Statement
Suppose Students table has a foreign key that references a Classroom table and we need to find out which student belongs to which classroom. We can resolve this by using JOIN statement:
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SELECT Students.StudentName, Classroom.ClassroomName FROM Students JOIN Classroom ON Students.ClassroomId = Classroom.ClassroomId; |
Conclusion
SQL is a powerful tool for managing and analysing large datasets, and the syntax is relatively straightforward to learn. Don’t be discouraged if you don’t understand everything at once. SQL, like any language, takes time to master. So keep experimenting and practicing!