Question

The _______ clause specifies a condition that needs to be satisfied by a group resulting from the group by clause in order to be selected.

A) JOIN
B) WHERE
C) HAVING
D) SELECT

Answer 1

The 'HAVING' clause in SQL is used in conjunction with the GROUP BY clause to specify conditions for filtering grouped rows in a database query.

Step-by-step explanation:

The missing term in the given sentence likely referring to SQL or a similar database query language is 'HAVING' clause. This clause is vital when dealing with SQL's GROUP BY clause, as it allows you to specify conditions that filter which groups to include in the result set. Unlike the WHERE clause, which filters rows before they are grouped, the HAVING clause is applied after grouping occurs.

For instance, if we have a database of sales records and we want to find out which products have a total sale amount greater than $1,000, we would use both GROUP BY to group the sales by product and HAVING to filter out the products that do not meet this condition.

An example of an SQL query utilizing both might look like this:

SELECT ProductID, SUM(SaleAmount) AS TotalSales
FROM Sales
GROUP BY ProductID
HAVING SUM(SaleAmount) > 1000;

The GROUP BY clause groups the records by ProductID, and the HAVING clause filters these groups to include only those where the sum of SaleAmount for the group is greater than $1,000.