SQL aggregate function

SQL aggregate function

SQL aggregate function allows the user to operate on a set of values and is the built in functions. Aggregate functions which take a collection ( A set or multi set ) of values as input and return a single value.
There are five built in SQL aggregate functions:

1.Average: avg

2.Minimum: min

3.Maximum: max

4.Total: sum

5.Count: count

The input to sum and avg must be a collection of numbers, but the other SQL operators can operate on non-numeric data types such as string, as well.
“Find the average balance at SARAWATHIPURAM branch”
We write the query as follows.

Select avg (balance) from account
Where br_name = “SARAWATHIPURAM ”

To find the number of rows in a table, we use count function.
“Find the total number of customers of the bank”

Select count(*)
From customer.

Similarly to find the maximum balance in SARAWATHIPURAM branch, we will  write the query as follows.
Select max (balance) from account
Where br_name = “SARAWATHIPURAM”
To find the minimum balance of a particular branch,
Select min(balance) from account

Where br_name = “SARAWATHIPURAM”

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