Quiz - C# Mastery Hub

1 What is a connection string used for?

To tell your app how to find the database

To store user passwords

To configure logging

To set the application name

2 What authentication method uses your Windows credentials?

SQL Authentication

Windows Authentication

Azure Authentication

Basic Authentication

3 Where should you store connection strings in an ASP.NET Core app?

Hard-coded in the C# file

In appsettings.json

In the database

In a text file

4 What is the correct syntax for a SQL Server connection string?

Server=localhost;Database=SchoolDB;Trusted_Connection=True;

Server=localhost;Database=SchoolDB;UseWindowsAuth=True;

Host=localhost;Database=SchoolDB;Auth=Windows;

Data Source=localhost;DB=SchoolDB;WindowsAuth=true;

5 How do you read a connection string from appsettings.json in C#?

Configuration.GetConnectionString('SchoolDb')

Configuration.GetString('SchoolDb')

Configuration.GetValue('SchoolDb')

Configuration.Read('SchoolDb')

6 Which NuGet package is needed for SQL Server connections in modern .NET?

System.Data.SqlClient

Microsoft.Data.SqlClient

Microsoft.SqlServer

System.SqlServer

7 What is the purpose of SqlCommand in ADO.NET?

To connect to the database

To execute SQL commands

To read data from the database

To store data

8 What does 'using' do with SqlConnection?

Makes the connection faster

Automatically closes and disposes the connection

Creates multiple connections

Encrypts the connection

9 What method reads data from a SqlCommand?

ExecuteReader()

ReadData()

GetData()

FetchData()

10 What is SqlParameter used for?

To store configuration values

To safely pass values to SQL commands

To create database tables

To read data from tables

11 Which method executes a command that doesn't return any rows?

ExecuteScalar()

ExecuteNonQuery()

ExecuteReader()

ExecuteTable()

12 What is the biggest risk of using string concatenation in SQL queries?

It makes the code slower

SQL Injection attacks

It uses more memory

It's hard to read

13 What is the correct way to pass values to a SQL command?

String concatenation

Using SqlParameter with @@ParameterName

Directly in the query string

Using string interpolation

14 What does ExecuteNonQuery() return?

The number of rows affected

A DataReader

A DataTable

A scalar value

15 Which of these is a safe SQL command?

DELETE FROM Students WHERE StudentId = 5

DELETE FROM Students WHERE StudentId = ' + studentId

DELETE FROM Students WHERE StudentId = @@StudentId

DELETE FROM Students WHERE StudentId = {studentId}

16 What is the main characteristic of SqlDataReader?

Loads all data into memory at once

Reads data forward-only, one row at a time

Allows editing data offline

Stores data in a DataSet

17 What is the main characteristic of SqlDataAdapter?

Reads data one row at a time

Loads data into a DataTable for offline access

Only executes stored procedures

Connects to multiple databases

18 Which one is better for binding to a Windows Forms DataGridView?

SqlDataReader

SqlDataAdapter

They are both the same

Neither works

19 Which one is more memory efficient for reading large datasets?

SqlDataAdapter

SqlDataReader

They use the same memory

Neither is memory efficient

20 What method fills a DataTable using SqlDataAdapter?

Load()

Fill()

Read()

Execute()

21 What does EF Core stand for?

Entity Framework Core

Entity Form Core

Environment Framework Core

Extended Framework Core

22 What is an ORM?

Object-Relational Mapper

Object-Resource Manager

Order-Resource Model

Object-Reference Model

23 What does DbSet represent in EF Core?

A single row in the database

A collection of entities that maps to a table

A database connection

A SQL command

24 What method saves changes to the database in EF Core?

Save()

SaveChanges()

SaveChangesAsync()

Both B and C

25 What is the advantage of EF Core over ADO.NET?

It's always faster than ADO.NET

You write less SQL and it's safer by default

It uses less memory

It connects to more databases

26 How do you read data in EF Core?

Using SQL strings

Using LINQ queries

Using stored procedures only

Using DataReader

27 Which method adds a new entity to the database in EF Core?

context.Add()

context.Insert()

context.Create()

context.New()

VS & SQL Connection Quiz