DATABASE LEVEL 1

What does the acronym "RDBMS" stand for, and how does it differ from a regular database?

• Relational Database Management System, stores data in tables with relationships

• Random Database Management System, organizes data without any specific structure

• Redundant Database Management System, duplicates data for backup purposes

• Resourceful Database Management System, efficiently manages system resources

Write an SQL query to retrieve all the records from a table named "employees" where the salary is greater than $50,000.

• SELECT * FROM employees WHERE salary > 50000;

• GET * FROM employees IF salary > 50000;

• RETRIEVE FROM employees WHERE salary > 50000;

• SHOW employees HAVING salary > 50000;

In a relational database, what is the purpose of a foreign key, and how does it relate to the concept of referential integrity?

• A foreign key is used to establish a link between two tables, enforcing referential integrity by ensuring that values in one table's key match the values in another table.

• A foreign key is used to encrypt sensitive data in a table, ensuring data security.

• A foreign key is used to create a duplicate of a table, improving data redundancy.

• A foreign key is used to sort data in a table, ensuring proper ordering.

What is the primary purpose of an Entity-Relationship Diagram (ERD) in the context of database design?

• To represent the structure of a relational database using tables and columns.

• To visualize the flow of data within a database system.

• To illustrate the entities, relationships, and attributes in a database and their connections.

• To optimize the performance of database queries.

In an ERD, what is an "entity," and what is the role of "attributes" associated with an entity?

• An entity represents a table, and attributes are the primary keys.

• An entity represents a real-world object or concept, and attributes describe the properties of that entity.

• An entity represents a relationship, and attributes are the foreign keys.

• An entity represents a transaction, and attributes are the timestamps.

What are the main types of relationships that can be represented in an ERD, and how are they visually depicted?

• Types: One-to-Many, Many-to-Many, One-to-One; Depicted using solid lines, dashed lines, and double lines, respectively.

• Types: Parent-Child, Sibling, Cousin; Depicted using arrows, circles, and squares, respectively.

• Types: Primary, Secondary, Tertiary; Depicted using different colors for each type.

• Types: Direct, Indirect, Reverse; Depicted using straight lines, curved lines, and zigzag lines, respectively.

What does the SQL acronym stand for, and what is its primary purpose in the context of databases?

• Structured Question Language; used for designing web pages.

• System Query Language; used for system-level operations in an operating system.

• Structured Query Language; used for managing and manipulating relational databases.

• Sequential Query Language; used for processing data sequentially.

What is the purpose of the SQL SELECT statement, and how is it used?

• Used for inserting new records into a table.

• Used for updating existing records in a table.

• Used for retrieving data from one or more tables.

• Used for deleting records from a table.

In SQL, what is the purpose of the WHERE clause, and how is it used in a SELECT statement?

• It is used to specify the columns to be retrieved in a SELECT statement.

• It is used to filter the rows returned by a SELECT statement based on a specified condition.

• It is used to join two or more tables in a SELECT statement

• It is used to order the result set in ascending or descending order.

What are SQL JOINs, and how are they used to combine data from multiple tables?

• SQL JOINs are used for creating new tables.

• SQL JOINs are used for sorting data in a table.

• SQL JOINs are used for combining rows from two or more tables based on related columns.

• SQL JOINs are used for renaming columns in a table.