Query | MCQs

Explanation

SQL is the specific language used to create tables, store, retrieve, and update data in a relational database.

It is designed for managing and manipulating structured data in relational databases.

Explanation

A "Select query" is used to retrieve data from a database.

It can filter records to show employees earning more than $5000 a month by specifying conditions.

Explanation

A dynaset is a collection of records that match the parameters of a query. 

It dynamically updates based on the query criteria set by the user.

Explanation

Worksheets and printables that help children practice key skills. 

Explanation

The QUERY can be used to select data from single and multiple tables.

Single Table Query:

When you want to retrieve data from a single table, you can use a simple SELECT statement.

Multiple Table Query:

To retrieve data from multiple tables, you use a JOIN clause. 

Explanation

• The correct answer is: Dept_id should not be used in group by clause (although this is not the case in the given query, as it uses dept_name)
• The error in the statement is that the ID column is not included in the GROUP BY clause. When using an aggregate function like AVG, all non-aggregated columns in the SELECT clause must be included in the GROUP BY clause.

Explanation

• The HAVING clause is used in SQL to filter groups of rows based on a condition, similar to how the WHERE clause filters individual rows.
• The HAVING clause is applied after the GROUP BY clause, which groups the rows into sets, whereas the WHERE clause is applied before the GROUP BY clause.