For an instructor lead, in-depth look at learning SQL click below.
Welcome to the world of Structured Query Language or SQL, the industry standard for interacting with databases! In this guide, we will cover the basics concepts, so let’s dive right in.
Introduction to SQL
SQL is a programming language that allows you to query, manipulate, and create data stored in relational databases. Let’s start with the basic SQL statements: SELECT, INSERT, UPDATE, and DELETE.
SELECT Statement
The SELECT statement is used to fetch data from a database. Here’s one example:
|
1 2 3 |
SELECT * FROM Students; |
This line of SQL code will retrieve all data from the ‘Students’ table.
INSERT Statement
The INSERT statement is used to add new records to a database. Here’s how it works:
|
1 2 3 4 |
INSERT INTO Students (StudentID, LastName, FirstName) VALUES (1, 'Doe', 'John'); |
This will add a new student called John Doe with the student ID 1 into the ‘Students’ database.
UPDATE Statement
The UPDATE statement is used to update records in a database:
|
1 2 3 4 5 |
UPDATE Students SET LastName = 'Smith' WHERE StudentID = 1; |
This SQL code will change the last name of the student with ID 1 to Smith.
DELETE Statement
The DELETE statement is used to delete existing records from a database:
|
1 2 3 4 |
DELETE FROM Students WHERE StudentID = 1; |
This will delete the student with ID 1 from the ‘Students’ table.
Conclusion
Great job on making it to the end of this beginner’s guide! At this point, you can run basic queries, which is the first step in exploiting the full power of SQL. Remember, practice is key when it comes to mastering any programming language, so make sure to use what you’ve learned in real scenarios.
Stay tuned for more advanced topics: JOINs, subqueries, and stored procedures!