SQL Basics: A Real-World Guide to Databases and Queries
If you’ve come across the word “SQL” and were not sure about it, you’re in the right place. This guide explains SQL in simple language. No prior technical knowledge is needed. What is a Database? Every time you order food through an app like Swiggy or Zomato, a lot happens behind the scenes. Your name, address, phone number, order history, and information related to your payments all need to be…
SQL Basics: Exploring Databases and Queries
What is SQL? SQL, or Structured Query Language, is a language used to interact with databases. It allows users to fetch information, add new records, update existing ones, and delete data. Pronounced as "S-Q-L" or "sequel", SQL is designed to be easily understandable, even for those without prior coding experience.
Four Basic SQL Commands
There are four primary SQL commands that cover almost all database operations:
1. SELECT - This command is used to retrieve data from a table. It allows users to view all data or specific columns within a table.
2. INSERT - Used to add new data to a database, INSERT command creates new records in a table.
3. UPDATE - This command modifies existing records in a database. It allows users to update specific fields within an existing record based on criteria.
4. DELETE - This command removes records from a database. It enables users to delete specific records based on certain conditions.
Food Delivery App Example Using SQL
In a food delivery app, SQL commands are used to manage user orders and information:
- SELECT command retrieves user data such as order history or customer names and cities.
- INSERT command adds new orders to the database when a user places an order.
- UPDATE command updates order status from pending to delivered once an order is completed.
- DELETE command removes orders that were mistakenly added to the database.
Why Learn SQL?
SQL is a valuable skill across many industries including banking, healthcare, retail, logistics, and tech. It is beginner-friendly as it uses familiar English-like syntax. With SQL knowledge, individuals can pursue roles in data analysis, database administration, backend development, and cloud platforms like Microsoft Azure.
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