Python and SQL Basics Quiz

The fetchmany() method of the cursor class in Python is used to retrieve a specified number of rows from a database table. It takes an integer argument (SIZE) representing the number of rows to be fetched.

In Python, all keywords are written in lowercase, except for three: True, False, and None. These three keywords are capitalized.

The rowcount attribute of the cursor class in Python is used to get the number of rows affected by the last database operation (insert, update, or delete) executed using the cursor. This provides information about the outcome of the operation.

A runtime error occurs during the execution of a program, causing the program to terminate abnormally, potentially due to issues like invalid input, resource exhaustion, or accessing a nonexistent file. It's different from syntax errors, which occur during code parsing.

A foreign key is an attribute in a table that references the primary key of another table. It establishes a link between the two tables, ensuring data integrity and consistency across related datasets.

Networking offers several benefits, including: file sharing, enabling easier access to resources across different locations, and facilitating backups. It's a crucial tool for communication, collaboration, and information management.

A logical error occurs during program execution, resulting in an undesired output without causing the program to crash. This indicates a flaw in the logic or algorithm used in the code, leading to incorrect results.

A candidate key is an attribute or set of attributes that can uniquely identify a row in a table. While a primary key is chosen as the unique identifier, other candidate keys exist. All candidate keys have the properties of a primary key.

The ORDER BY clause in SQL sorts results in ascending order by default. This means it arranges rows from the lowest to the highest value in the specified column.

A primary key uniquely identifies each record in a table. It can't contain duplicate values and is essential for data integrity. Roll No. fits this requirement, as each student should have a unique roll number.

The "VALUES" keyword is used with the INSERT statement in SQL to specify the data to be inserted into the table.

The LIKE operator is used to search for data based on patterns. In this case, the pattern '_____A' matches any 5-letter last name ending with 'A'.

The ID attribute is the most suitable primary key for the Student table because it uniquely identifies each student. Other attributes might have duplicates, making them unsuitable for reliably distinguishing students.

The DISTINCT keyword removes duplicate values from the output, ensuring that only unique values of the column are displayed.

The AS keyword allows you to rename a column alias in SQL. It makes the query more readable and specific.

The LIKE operator with '%' wildcard helps find data where the column 'FirstName' ends with 'a'. The '%' represents any number of characters before 'a'.

A network device that connects multiple computers in a network, allowing them to communicate with each other. In this case, a switch would be the best choice for connecting multiple computers in a cyber cafe.

Structured Query Language (SQL) is a standardized language for accessing and manipulating data in relational databases.

A database management system (DBMS) uses Data Manipulation Language (DML) to modify the data stored in a database. These commands are used to insert, delete, and update data.

The WHERE clause in a SQL SELECT statement specifies criteria that the data must match to be included in the results. It acts like a filter, selecting only the rows that meet the defined condition.

MAX() is a function in SQL (specifically in MySQL) that finds the largest value in a column. It's a convenient way to identify the maximum value in a set of data.

CHAR(n) creates fixed-length string fields, meaning they always have a specific number of characters. VARCHAR(n) creates variable-length string fields, meaning they can be different lengths. This allows for efficient storage of strings.

A tuple in a relational database refers to a single row in a table. Each tuple represents a complete set of data for an individual entity in the database.

A relational database is structured as a collection of tables. Each table contains data about a particular subject or entity in a structured format.