SQL EXISTS vs JOIN: Find Customers Who Have Placed an Order#88 SQL Challenge: Can You Find Customers Who Have Placed an Order? Imagine your manager asks you to find all customers who have placed at least one order. You have two tables. Some customers have pla1d ago · 3 min readsankalandtech.hashnode.dev
SQL: WHERE, ORDER BY, and LIMIT — Why Your Query May Return the Wrong EmployeesA SQL query can run successfully and still return the wrong result. Imagine your manager asks you to find the three highest-paid employees in the IT department. You write a query, execute it, and get 2d ago · 3 min readsankalandtech.hashnode.dev
SQL Filtering and Sorting: 5 Mistakes That Can Change Your Query ResultsA SQL query can execute without errors and still produce an unexpected result. It might return the wrong employees, sort salaries incorrectly, or select the wrong three records. The problem often lies3d ago · 3 min readsankalandtech.hashnode.dev
SQL SELECT Statement: Practical Examples for Beginners and Interview PreparationThe "SELECT" statement is one of the first things you learn when working with SQL. But knowing the syntax is only the beginning. In real projects, you need to retrieve the right columns, filter record4d ago · 5 min readsankalandtech.hashnode.dev
A Single SQL Constraint Can Save Your Database From Bad Data — Do You Know Which One?A Single SQL Constraint Can Save Your Database From Bad Data Imagine an order references a customer who doesn't exist. Your reports become unreliable, your joins return unexpected results, and debuggiOct 22 · 2 min readsankalandtech.hashnode.dev
