Q.(a) Find sum of Sale Price of the cars purchased by the customer having ID C0001 from table SALE.

SQL Rounding Functions

Imagine you're keeping a record of your monthly expenses. You spend ₹1,247.83 on groceries, ₹532.19 on transport, and ₹2,108.56 on rent. When you tell a friend how much you spent, you don't say "one thousand two hundred forty-seven point eight three rupees." You say "about ₹1,250" or "roughly ₹1,200." That instinct to simplify a number to something easier to work with — that's exactly what rounding functions do in SQL.

The Core Idea

Rounding functions take a number with many decimal places and give you back a cleaner version. They don't change the kind of number — it's still a number — but they make it shorter, neater, and often more useful for reports, summaries, or display.

Think of it like this: you have a precise measurement, but you don't always need that precision. A bank statement might show ₹1,247.83, but a budget summary might only need ₹1,248. A sales report for the whole year might round to the nearest thousand. SQL gives you the tools to decide exactly how much precision you want to keep.

The Main Rounding Functions

SQL provides several ways to round, and each one behaves a little differently. Here's what you need to know:

ROUND — This is the most intuitive one. It takes a number and rounds it to a specified number of decimal places. If you round 3.14159 to two decimal places, you get 3.14. If you round it to zero decimal places, you get 3. The rule is standard: look at the next digit; if it's 5 or above, round up; otherwise, round down. This is what most people mean when they say "round."

CEILING — This function always rounds up to the nearest whole number, no matter what. If your number is 3.001, CEILING gives you 4. If it's 3.999, you still get 4. It's like saying "I don't care how close you are — go to the next integer." This is useful when you're counting things that can't be split, like people or items. You can't have 3.2 employees; you need 4.

FLOOR — This is the opposite of CEILING. It always rounds down to the nearest whole number. 3.999 becomes 3. 3.001 becomes 3. It's like saying "cut off everything after the decimal point, no questions asked." This is handy when you're dealing with quantities where you can't exceed a limit, like "how many full boxes can I pack?"

Why Rounding Matters in the Real World

You might wonder: why not just store the exact number? Because in practice, data is messy and human beings need simplicity. …