ITSW 3024 D387 Advanced Java

Correct Answer

B. To communicate with a database for data manipulation

Explanation

SQL (Structured Query Language) is specifically designed for managing and manipulating data in relational databases. Its primary purpose is to allow users to perform operations such as inserting, updating, retrieving, and deleting data from database tables. SQL commands form the essential bridge between applications and the data they rely on.

Why other options are wrong

A. To create user interfaces for web applications

This is incorrect because creating user interfaces is typically done with front-end technologies like HTML, CSS, and JavaScript, not SQL. SQL operates in the backend, managing data, not interface elements.

C. To compile Java programs into bytecode

This is incorrect because compiling Java programs into bytecode is handled by the Java compiler (javac), not SQL. SQL has no role in the process of Java compilation or bytecode generation.

D. To manage server configurations

This is incorrect as server configuration is handled using configuration files and tools like shell scripts or software such as Ansible or Docker. SQL is not used to manage hardware or software configuration settings.

Correct Answers: A. Use of tamoxifen, C. Diabetes, D. Lynch syndrome, E. Obesity

Explanation of Correct Answers

A. Use of tamoxifen

Tamoxifen, while an anti-estrogen in breast tissue, has partial estrogen agonist effects on the endometrium, increasing the risk of endometrial hyperplasia and cancer.

C. Diabetes

Diabetes is associated with insulin resistance and hyperinsulinemia, which promote cellular proliferation and increase the risk of endometrial cancer.

D. Lynch syndrome

This hereditary cancer syndrome (due to mismatch repair gene mutations) significantly increases the risk of endometrial cancer, alongside colorectal and other cancers.

E. Obesity

Obesity is one of the strongest risk factors. Excess adipose tissue increases estrogen production through peripheral aromatization, stimulating the endometrium and raising cancer risk.

Correct Answer

D. It is used to query data in a database.

Explanation

The SELECT statement in SQL is primarily used to retrieve data from one or more tables within a database. It allows users to specify the columns they wish to view and to apply filters, sorting, and aggregation to extract meaningful information. It is the most commonly used SQL command for data retrieval operations.

Why other options are wrong

A. It is used to update data in a database.

This is incorrect because the UPDATE statement, not SELECT, is used to modify existing records in a database table. The UPDATE command is specifically intended for changing data values already stored.

B. It is used to insert data into a database.

This is incorrect as the INSERT INTO statement is used when new data is being added to a table. The SELECT statement does not add new rows—it only reads existing ones.

C. It is used to delete data from a database.

This is incorrect because the DELETE statement is responsible for removing data from a table. SELECT has no effect on the underlying data—it only queries and displays it.

Correct Answer

B. The server executes an SQL command to fetch data from the database based on the query and then dynamically generates the web page content.

Explanation

When a user submits a search query on a dynamic web page, the server processes the request by executing an SQL query against a database like MySQL. The resulting data is then used to dynamically generate and render the content of the web page, ensuring that the user receives relevant and updated information based on their input. This is a key aspect of how dynamic web applications operate.

Why other options are wrong

A. The server retrieves the query results from a cache and displays them without database interaction.

This is incorrect because while caching mechanisms exist, they are not typically the default behavior for handling unique search queries. Most search requests require real-time interaction with the database to ensure accuracy and relevance unless specifically optimized with caching.

C. The web page reloads with static content that does not change based on the query.

This is incorrect because static content does not change regardless of user input. Dynamic pages, by contrast, change based on user interactions such as search queries. If the content were static, the results would not reflect the user’s search criteria.

D. The server sends the query directly to the user's browser for processing.

This is incorrect because SQL processing is done on the server side for both security and performance reasons. Allowing the browser to process SQL queries would pose significant security risks and is not a supported web development model.

Correct Answer

B. Software that enables users to manage data and its schema.

Explanation

A Database Management System (DBMS) is software that facilitates the creation, management, and manipulation of databases. It provides an interface for users to interact with the data stored in a database, including defining and managing data structures, storing data, and querying the database. The DBMS ensures data integrity, security, and efficient access to the data.

Why other options are wrong

A. A programming language used for web development

This is incorrect because a DBMS is not a programming language. It is software used for managing and interacting with databases, while programming languages like JavaScript, PHP, or Python are used to develop web applications.

C. A type of hardware used for data storage

This is incorrect because a DBMS is not hardware. While databases are stored on hardware like hard drives or servers, a DBMS is software that manages the data stored on that hardware.

D. An application for designing user interfaces

This is incorrect because a DBMS is focused on data management, not user interface design. User interface design is typically handled by different software tools or frameworks, not a DBMS.

Correct Answer

B. They indicate how data is to be stored and what can be done with it

Explanation

Data types in SQL define the type of data that can be stored in a column, such as integer, string, or date. They determine the amount of memory allocated for each value and define what operations can be performed on the data (e.g., mathematical operations for numeric data types, or string operations for text data types). Proper use of data types ensures data integrity and efficient storage.

Why other options are wrong

A. They are used to organize data in a tabular format

While data types play a role in organizing data within columns, they do not directly organize the data into a tabular format. The tabular structure is defined by the table itself, not the data types.

C. They are used to name tables and columns

Data types are not used for naming tables or columns. Column names and table names are defined separately from data types. Data types only specify the type of data a column can hold.

D. They are used to assign primary keys

Data types are not used to assign primary keys. Primary keys are assigned to columns to uniquely identify records in a table, but data types define what kind of data can be stored in those columns. The primary key constraint is a separate concept in SQL.

Correct Answer

A. JDBC.

Explanation

Java programs communicate with databases using the JDBC (Java Database Connectivity) API. JDBC provides a set of interfaces and classes that allow Java applications to connect to databases, execute SQL queries, and process the results. It is a standard API used for relational database interaction in Java, enabling developers to integrate databases into their Java applications easily.

Why other options are wrong

B. DBMS.

This is incorrect because DBMS refers to a Database Management System, which is the software used to manage databases. JDBC, on the other hand, is the API used by Java programs to interact with a DBMS.

C. RDBMS.

This is incorrect because RDBMS stands for Relational Database Management System. While JDBC is used to interact with RDBMS, RDBMS itself is not an API but rather a type of database management system.

D. Database.

This is incorrect because "Database" is simply the collection of data stored and managed by a DBMS. It is not an API. JDBC is the API that enables Java programs to communicate with databases.

Correct Answer

C. Log the error and provide specific feedback to the user about what went wrong.

Explanation

Effective error handling in web applications enhances user experience by ensuring that users receive clear, actionable feedback when issues arise. Logging errors is essential for developers to diagnose problems, while user-specific error messages help guide corrections. For example, informing users that a required field is missing or an input format is incorrect allows them to resolve the issue and successfully complete their task.

Why other options are wrong

A. Ignore the error and allow the submission to proceed.

This is incorrect because submitting invalid data can lead to database inconsistencies, application errors, or security vulnerabilities. Ignoring validation undermines data integrity and can confuse users when expected outcomes do not occur.

B. Display a generic error message without details.

This is incorrect because generic messages do not help users understand or fix the problem. Providing specific guidance (e.g., "Email format is invalid") improves user satisfaction and task completion rates. Generic messages can also lead to frustration and repeated failed attempts.

D. Redirect the user to the homepage.

This is incorrect because it disrupts the user experience and provides no insight into the error. It may cause users to abandon the process altogether. Instead of helping, this approach hides the problem and prevents users from correcting their input.

Correct Answer

A. INSERT INTO users (username, email) VALUES ('john_doe', '[email protected]');

Explanation

This is the correct SQL syntax for inserting a new record into the 'users' table with the specified 'username' and 'email'. The INSERT INTO statement is used to insert data into specific columns of a table, and the VALUES keyword is used to specify the values for those columns.

Why other options are wrong

B. INSERT users (username, email) VALUES ('john_doe', '[email protected]');

This syntax is incorrect because it omits the INTO keyword, which is required in the SQL INSERT statement.

C. INSERT INTO users VALUES ('john_doe', '[email protected]') (username, email);

This is incorrect because the parentheses at the end of the statement (username, email) are unnecessary and improperly placed. Column names should be included right after the INSERT INTO table_name syntax, not after the values.

D. INSERT INTO users (username, email) SET ('john_doe', '[email protected]');

The SET keyword is not used in the INSERT INTO statement. It is typically used in UPDATE statements. The correct syntax for an INSERT statement is to use VALUES to provide the data.