SQL is the language used to query relational databases, and to insert, update, and delete data. For example, you can use an SQL query to do things like "show me the customers from Mexico," "count the number of orders," or "update this customer's phone number."
When do you actually use it?
You reach for SQL when showing a user list on an admin dashboard, generating a sales report, searching for a product from a search box, or when a backend API needs to query the database for data.
Important note
SELECT * shows every column in a table. It's handy while learning, but in production apps, selecting only the columns you actually need is faster and cleaner.
sql
SELECT * FROM Customers;You should see
What this code does: It pulls every row and every column from the Customers table. Expected output: You'll see the customer records in the Customers table displayed as a table. Common mistake: Errors can happen from misspelling the table name, forgetting the semicolon, or the table not existing yet in the database.