Month: September 2024

At first, the term "multi-tenancy" might sound like a technical challenge, but it’s actually a straightforward strategy for organizing software to serve multiple users seamlessly. While the concept itself is simple to grasp, its implementation can vary depending on the specific needs of different applications.

Let’s begin by defining what multi-tenancy really means.

Multi-tenant SaaS applications are a type of software that allows multiple users to access the same software instance. This is achieved by partitioning the software into separate, isolated environments that are dedicated to each tenant. Customer data could be stored in a separate database for each tenant, or in a shared database with data assigned to tenants by unique identifiers.

If you’re looking for a new keyboard, there are many options. Apart from different sizes and switches, different layouts provide a more ergonomic user experience. Depending on how much you type, the comfort an Alice keyboard provides might just be reason enough to switch.

What Is an Alice Keyboard?

Alice keyboards split the traditional keyboard layout into two parts and angle the keys, so minimal wrist movement is required when typing. They’re also fairly new, with the first Alice-style keyboards designed by keyboard enthusiast Yuk Tsi in 2018. The split format in a single frame results in a much more ergonomic and comfortable typing experience than the standard "slab" keyboards we’re all used to.

Additionally, since your wrists aren’t moving as much, your shoulders and forearms feel more at ease during longer typing sessions. Note that Alice keyboards aren’t the same as split keyboards, which are divided from the middle into two separate units, each covering one side of the QWERTY layout.

Just like every other keyboard on the market, there’s a fair amount of customization, layout, and design options you can choose from when looking for an Alice keyboard. Since most, if not all, Alice keyboards you’ll find will be mechanical, you can change things like the switches and keycaps and even install mods to enhance the sound or feel of your keyboard.

The mods aren’t very different from regular keyboards either, so you can easily adapt them to the Alice format. Since they’re mostly mechanical, you’ll also be able to fix your keyboard when it doesn’t work as relatively easily.

More interestingly, Alice keyboards come in a few different options. These options vary between keyboards that change the number of keys, their alignment or orientation, and sometimes add extra features like additional buttons or dials.

How Are They Different From Regular Keyboards?

Alice keyboards, even in the QWERTY layout, differ from regular ones. It’ll take a while to get used to an Alice keyboard when first starting out, as the keys are in different places and angled differently. You’ll also try to subconsciously move your wrists, which throws you off at first.

However, once you get used to the layout, the real benefits of the Alice keyboard start kicking in. Since your wrists aren’t moving as much, you won’t feel as exhausted after long typing sessions. Additionally, if you have wrist pain or issues like carpal tunnel syndrome, an Alice keyboard can go a long way in providing comfort.

Why You Should Switch to an Alice Keyboard

The main reason you should switch to an Alice keyboard, especially if you type a lot, is comfort. They aren’t necessarily as ergonomic as the keyboard manufacturer would want you to think, but they’re easier on your wrists, forearms, and shoulders compared to a regular keyboard.

Just like gaming keyboards can be a great fit for even non-gamers, Alice keyboards are the next step. That is if you’re okay paying for them. Alice keyboards are not a popular product, so expect some markup from manufacturers. You can find some pretty good budget options, such as the Keychron V8 Max or Epomaker Cidoo, coming in at $100 and $45, respectively, at the time of writing.

There is a catch, though. Regular and fully split keyboards offer much more freedom of movement when typing, allowing you to type in different positions. Alice keyboards will work best when you’re in a certain position, meaning you won’t get to move around that much. If you often find yourself typing in different positions, an Alice keyboard might not be the best decision.

Overall, an Alice keyboard will provide better comfort during long typing sessions, with the same advantages as any regular mechanical keyboard. So, if you’re a programmer, writer, or anyone who spends a significant amount of time typing, you should definitely consider an Alice keyboard.

Storing currency values in a database might seem like a trivial task, but it can become complicated due to issues like precision and rounding errors. This article will discuss several strategies for storing currency or money in a MySQL database, along with their pros and cons.

DECIMAL Data Type

The most recommended way to store currency is by using the DECIMAL data type. DECIMAL can store exact numeric data values, unlike FLOAT or DOUBLE, which are approximate numeric data types.

Here is an example of how to define a DECIMAL field for storing currency:

CREATE TABLE products (
    id INT AUTO_INCREMENT,
    price DECIMAL(19,4),
    PRIMARY KEY(id)
);

In this example, DECIMAL(19,4) means that the price field will store numbers that have up to 19 digits, including 4 digits after the decimal point.

Advantages:

Accurate to the last penny (or even beyond, depending on your specified decimal places), making it perfect for financial calculations. It is sometimes the guidelines of government financial bodies to store to 4 decimal places, even for currencies with only 2 decimal places. This is to increase precision when calculating tax.

Disadvantages:

• DECIMAL columns take more storage space compared to FLOAT or DOUBLE.
• Math operations with DECIMAL columns are slower compared to FLOAT or DOUBLE.

FLOAT or DOUBLE Data Types

Another way to store currency is by using FLOAT or DOUBLE data types, which can store approximate numeric data values.

CREATE TABLE products (
    id INT AUTO_INCREMENT,
    price FLOAT,
    PRIMARY KEY(id)
);

Advantages:

• FLOAT and DOUBLE columns take less space compared to DECIMAL.
• Math operations with FLOAT or DOUBLE are faster compared to DECIMAL.

Disadvantages:

• FLOAT and DOUBLE cannot store exact values, which can lead to rounding errors. This makes them a poor choice for financial calculations where precision is essential.

Storing Cents Instead of Dollars

Another strategy is to store the money value in cents (or the smallest unit of your currency) as an INTEGER.

CREATE TABLE products (
    id INT AUTO_INCREMENT,
    price INT,
    PRIMARY KEY(id)
);

In this case, if the price of a product is $19.99, you would store 1999 in the price column.

Advantages:

• Since you are storing an integer, the calculations will be exact, and you will not have to worry about rounding errors.

Disadvantages:

• This approach requires you to manually convert between dollars (or your main currency unit) and cents in your application logic.

Choosing the right method to store currency values in your MySQL database depends on your specific use case. If exactness is critical, as it usually is in financial applications, DECIMAL is often the best choice despite its higher storage costs and slower calculations. FLOAT and DOUBLE could be used for applications where the speed of calculations is more important and a minor loss of precision can be tolerated. Storing money as cents in an INTEGER field is another approach that ensures exact calculations and could be convenient for certain applications.

The Pipeline pattern in Laravel provides an elegant way to pass data through a series of operations. This pattern is particularly useful for complex workflows or when you need to apply a sequence of transformations to your data. Let’s explore how to implement and leverage the Pipeline pattern in your Laravel applications.

Basic Pipeline Usage

Here’s a basic example of using Laravel’s pipeline:

use Illuminate\Support\Facades\Pipeline;

$result = Pipeline::send($order)
    ->through([
        ValidateOrder::class,
        ApplyDiscount::class,
        CalculateTax::class,
        ProcessPayment::class,
    ])
    ->then(fn ($order) => $order->complete());

In this example, an $order object is passed through a series of operations before being completed.

Creating Pipeline Steps

Each step in the pipeline should be a class with an __invoke method:

class ValidateOrder
{
    public function __invoke($order, $next)
    {
        // Perform validation logic
        if (!$order->isValid()) {
            throw new InvalidOrderException();
        }

        return $next($order);
    }
}

Passing Additional Parameters

You can pass additional parameters to your pipeline steps:

$result = Pipeline::send($order)
    ->through([
        ValidateOrder::class,
        [ApplyDiscount::class, $discountCode],
        [CalculateTax::class, $taxRate],
        ProcessPayment::class,
    ])
    ->then(fn ($order) => $order->complete());

In your pipeline step:

class ApplyDiscount
{
    public function __invoke($order, $next, $discountCode)
    {
        // Apply discount logic using $discountCode
        return $next($order);
    }
}

Using the Pipeline in Controllers

Implement the pipeline in your controller for clean, modular code:

class OrderController extends Controller
{
    public function store(Request $request)
    {
        $order = new Order($request->all());

        return Pipeline::send($order)
            ->through([
                ValidateOrder::class,
                SaveOrder::class,
                NotifyCustomer::class,
            ])
            ->then(fn ($order) => response()->json($order, 201));
    }
}

Error Handling in Pipelines

Handle exceptions within your pipeline steps:

class ProcessPayment
{
    public function __invoke($order, $next)
    {
        try {
            // Process payment logic
            PaymentGateway::charge($order->total);
        } catch (PaymentFailedException $e) {
            return response()->json(['error' => 'Payment failed'], 400);
        }

        return $next($order);
    }
}

Creating Reusable Pipelines

For frequently used pipelines, create a dedicated class:

class OrderProcessingPipeline
{
    public function __invoke($order)
    {
        return Pipeline::send($order)
            ->through([
                ValidateOrder::class,
                ApplyDiscount::class,
                CalculateTax::class,
                ProcessPayment::class,
            ])
            ->then(fn ($order) => $order->complete());
    }
}

Use it in your controller:

public function store(Request $request, OrderProcessingPipeline $pipeline)
{
    $order = new Order($request->all());
    return $pipeline($order);
}

Conditional Pipeline Steps

Add or remove steps based on conditions:

$steps = [ValidateOrder::class, SaveOrder::class];

if ($request->has('discount_code')) {
    $steps[] = ApplyDiscount::class;
}

$steps[] = ProcessPayment::class;

return Pipeline::send($order)
    ->through($steps)
    ->then(fn ($order) => response()->json($order, 201));

The Pipeline pattern in Laravel offers a clean, modular approach to handling complex workflows. By breaking down your logic into small, focused steps, you can create more maintainable and testable code. This pattern is particularly useful for processes like order processing, user registration, or any scenario where you need to apply a series of operations to your data in a specific order.

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When you’re staring at a massive spreadsheet, counting cells manually isn’t just tedious—it’s a recipe for mistakes. Thankfully, Microsoft Excel’s COUNTIF formula swoops in to save the day. It lets you count cells based on specific text or conditions, turning your spreadsheet chaos into organized data magic.

How to Count Excel Cells Based on a Condition

Not to be confused with the SUM function, which adds up numerical values within a group of cells, the COUNT function on Excel establishes the number of cells that contain a value.

In the image above, the COUNT function produces the number of paychecks released in a single week. But in its basic form, this function will only take you so far. Its sister functions, COUNTIF and COUNTIFS, can narrow those results into only the cells that meet a condition or have a specific string.

For example, you might need to calculate only the number of checks over a certain dollar amount or paychecks related to particular people. In these cases, you’ll need to use COUNTIF and COUNTIFS.

Excel’s COUNTIF and COUNTIFS functions are exactly how they sound: they will count cells for you IF those cells meet criteria that you specify.

How to Count Cells With COUNTIF

You should use COUNTIF when you have just one condition to factor in. This function is handy when you need to count cells that exceed (or fall under) a specified number.

In the above image, an Excel sheet breaks down the payroll for two separate pay weeks. An Earned column contains a formula that calculates the amount of money a performer earned depending on a session fee and number of sessions. On a week during which a performer had no sessions, their total earned was 0, meaning they did not receive a paycheck.

Whereas the basic COUNT function would consider a 0 to be a numerical value and hence count it as a paycheck, I can instead use COUNTIF to clarify that I only want to count cells with numerical values over 0.

To use COUNTIF:

1. Select the cell in which you’d like to display your COUNTIF output.
2. Type in the =COUNTIF function.
3. Within a set of parentheses, you should first include a cell range of where you want the function to look, a comma, and then what (a value, for instance) you want the function to look for.
4. Hit Enter.

If I want to know how many paychecks were released during that week, I use the following formula:

=COUNTIF(E3:E8, >"0") 

The COUNTIF function is also useful when you have a dataset that contains repetitive values. Say I was looking at a statement of paychecks over a wide date range, and I needed to quickly count checks per person.

I could establish a column with each performer’s name, and use that cell number as the condition to count their paychecks:

=COUNTIF(A3:A9, F3) 

If I didn’t want to include a name column, I could alternatively use the exact text of their names in the COUNTIF function instead:

=COUNTIF(A3:A9, "P. King") 

Both of these functions will output the same result.

How to Count Cells With COUNTIFS

Maybe you’re set at this stage, or perhaps you need to implement additional conditions. Luckily for you, COUNTIF walked so COUNTIFS could run. Regarding the differences between COUNTIF and COUNTIFS, the gist is that COUNTIFS allows you to use multiple conditions instead of just one.

To use COUNTIFS:

1. Select the cell in which you’d like to display your COUNTIFS output.
2. Type in the =COUNTIFS function.
3. A set of parentheses includes a cell range, a comma, the first value or condition you’d like the program to look for, a comma, a second cell range, a comma, and another condition.
4. Hit Enter.

Here’s one example of what the formula might look like:

=COUNTIFS(B3:B18, G3, E3:E18, ">0") 

In this example, the spreadsheet calculates the number of paychecks per performer over multiple weeks by first specifying the person and secondarily establishing that we’re looking for any value over 0.

You might also want to not only separate paychecks per performer but also separate lower paycheck values from higher paycheck values.

In this example, which is based on a list of payroll checks released over a range of dates, the following function will establish the amount of high-value paychecks that were over $1,000 for a specific performer:

=COUNTIFS(A3:A9, "P. King", B3:B9, ">1000") 

Of course, the possibilities of the COUNTIF and COUNTIFS functions are virtually endless. You can take these functions to the next level by combining them with Excel’s wildcard symbols and nested IF statements in Excel. Ultimately, the right function for you depends on your dataset and what information you need to analyze.