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Using SqlDataReader asynchronously prevents blocking the main thread, improving performance in web apps and large queries. Here’s how to do it properly.
Use await with ExecuteReaderAsync()
using (SqlConnection conn = new SqlConnection(connectionString)) { await conn.OpenAsync(); using (SqlCommand cmd = new SqlCommand("SELECT * FROM Users", conn)) using (SqlDataReader reader = await cmd.ExecuteReaderAsync()) { while (await reader.ReadAsync()) { Console.WriteLine(reader["Username"]); } } // ✅ Auto-closes reader } // ✅ Auto-closes connection
Why use async?
A couple of reasons:
⚡ Alternative: ConfigureAwait(false) for ASP.NET
Use ConfigureAwait(false) in library code to avoid deadlocks in UI frameworks like ASP.NET.
using (SqlConnection conn = new SqlConnection(connectionString)) { await conn.OpenAsync().ConfigureAwait(false); using (SqlCommand cmd = new SqlCommand("SELECT * FROM Users", conn)) using (SqlDataReader reader = await cmd.ExecuteReaderAsync().ConfigureAwait(false)) { while (await reader.ReadAsync().ConfigureAwait(false)) { Console.WriteLine(reader["Username"]); } } }
Storing passwords as plain text is dangerous. Instead, you should hash them using a strong, slow hashing algorithm like BCrypt, which includes built-in salting and resistance to brute-force attacks.
Step 1: Install BCrypt NuGet Package
Before using BCrypt, install the BCrypt.Net-Next package:
dotnet add package BCrypt.Net-Next
or via NuGet Package Manager:
Install-Package BCrypt.Net-Next
Step 2: Hash a Password
Use BCrypt.HashPassword() to securely hash a password before storing it:
using BCrypt.Net; string password = "mySecurePassword123"; string hashedPassword = BCrypt.HashPassword(password); Console.WriteLine(hashedPassword); // Output: $2a$12$...
Step 3: Verify a Password
To check a user's login attempt, use BCrypt.Verify():
bool isMatch = BCrypt.Verify("mySecurePassword123", hashedPassword); Console.WriteLine(isMatch); // Output: True
Ensuring proper hashing should be at the top of your list when it comes to building authentication systems.
String interpolation, introduced in C# 6.0, provides a more readable and concise way to format strings compared to traditional concatenation (+) or string.Format(). Instead of manually inserting variables or placeholders, you can use the $ symbol before a string to directly embed expressions inside brackets.
string name = "Walt"; string job = 'Software Engineer'; string message = $"Hello, my name is {name} and I am a {job}"; Console.WriteLine(message);
This would produce the final output of:
Hello, my name is Walt and I am a Software Engineer
String interpolation can also be chained together into a multiline string (@) for even cleaner more concise results:
string name = "Walt"; string html = $@" <div> <h1>Welcome, {name}!</h1> </div>";
In C#, you can format an integer with commas (thousands separator) using ToString with a format specifier.
int number = 1234567; string formattedNumber = number.ToString("N0"); // "1,234,567" Console.WriteLine(formattedNumber);
Explanation:
"N0": The "N" format specifier stands for Number, and "0" means no decimal places. The output depends on the culture settings, so in regions where , is the decimal separator, you might get 1.234.567.
Alternative:
You can also specify culture explicitly if you need a specific format:
using System.Globalization; int number = 1234567; string formattedNumber = number.ToString("N0", CultureInfo.InvariantCulture); Console.WriteLine(formattedNumber); // "1,234,567"
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