Forem: Syeda Maham Fahim

How to Import/Export CSV file in pgAdmin

Syeda Maham Fahim — Thu, 13 Feb 2025 10:13:23 +0000

Working with databases often involves handling large amounts of data. One of the most common ways to import or export data is through CSV files.

This article covers simple steps for importing and exporting CSV files using pgAdmin.

Let’s get started!

Importing CSV into pgAdmin

Right-click on the table where you want to import the CSV file.
- A popup will appear.
Click on the folder icon (highlighted in the green square).
- A new popup will open.
Click on the three horizontal dots on the right side of the popup.
- A dropdown menu will appear with the “Upload” option.
Upload the file.
- After selecting the "Upload" option, a new popup will appear where you can choose your file.
- Note: The maximum file size is 50MB, so make sure your file doesn't exceed this limit.
Close the popup by clicking on the first 'X' button. Don’t click the second one as it will remove the file from the list.
Select the file you just uploaded.
Ensure the CSV Columns Match the Database.
- Make sure the columns in your CSV match those in your database table.
- In the screenshot below, the database columns are id, published_date, city, etc.
CSV Columns.
- Similarly, ensure that your CSV file has the same columns in the same positions as the database.
- Note: The id column is not included in the CSV because PostgreSQL will generate this automatically.

Excluding Unwanted Columns

Exclude unwanted columns.
- In the "Columns" tab, remove the columns that you don’t want to import (e.g., id, created_at, updated_at).
Click OK to complete the import process. Your CSV file will be successfully imported into pgAdmin.

Exporting CSV from pgAdmin

Go to the Export tab and click the folder icon to choose the file location where you want to export your data.
Click the 'Export' button to start the process. Once completed, a success message will appear

Accessing the Exported CSV

Where to find your exported CSV file?
- Don’t worry! You can easily find your exported file by clicking on the Tools option in the header, followed by Storage Manager.
A new popup will show all your stored files.
Select the file and click on the download button to get your exported CSV file.

Conclusion

And there you have it!

You've learned how to import and export CSV files in pgAdmin easily.

This process is quite simple once you get the hang of it, and it's a great way to manage your data.

Stay Connected - @syedamahamfahim 🐬

How to Generate and Use SSH Keys In Windows

Syeda Maham Fahim — Mon, 27 Jan 2025 20:58:47 +0000

When working with remote servers, SSH keys are a secure and convenient way to authenticate without repeatedly entering passwords.

PuTTY

PuTTY is one of the most popular tools to generate SSH keys on Windows and connect to servers like AWS or DigitalOcean.

In this guide, I’ll walk you through the steps to install PuTTY, create SSH keys, and set up secure connections with servers. Let’s get started!

1. Installing PuTTY

Download PuTTY from its official website.
Choose the version that matches your system's configuration (32-bit or 64-bit).

Once downloaded, install PuTTY by following the on-screen instructions.

2. Open PuTTY

After installation, search for PuTTY in your system's search bar and open it.

This will open the main PuTTY screen where you can generate SSH keys.

3. Generate an SSH Key

Open PuTTYgen, a key generator tool included with PuTTY. You’ll see the following screen:

Click on Generate to start creating your SSH key.
You will be asked to move your mouse randomly over the blank space in the PuTTYgen window to generate randomness (entropy) for a secure key.

After the process is complete, you’ll see your SSH key displayed in the window:

4. Save Your SSH Keys

Copy the public SSH key displayed in the box. This key will be pasted into the server's SSH settings.
Click Save private key to store the private key securely on your computer.

Tip: The private key is critical because it can regenerate the public key whenever needed. Make sure to save it in a secure location!

5. Regenerate Public Key from Private Key

If you ever lose your public key, don’t worry! You can easily regenerate it from your saved private key.

Open PuTTYgen again.
Click on Load and select your saved private key file.

Your public key will be displayed again, ready to use.

6. Connect to a Server Using Your SSH Key

Now that your SSH keys are ready, you can use them to connect to remote servers. Simply:

Copy the public key to your server's SSH settings (e.g., AWS or DigitalOcean).
Use the private key when logging in through PuTTY to authenticate securely.

Final Thoughts

Setting up SSH keys on Windows using PuTTY is straightforward and ensures secure connections to remote servers. Remember these key points:

Save your private key securely.
Use your public key to set up server authentication.

Stay Connected - @syedamahamfahim 🐬

How to create a custom filter in Django Admin/CMS

Syeda Maham Fahim — Mon, 27 Jan 2025 13:59:22 +0000

It is literally amazing that Django provides so many built-in filters. Imagine how much time the Django admin panel saves us. Moreover, its filtration functionality is outstanding.

For example, you only have to define the list_filter in your admin class and boom – you get fully functional filters like this:

Just focus on list_filter

But what if you want to add custom filters based on specific criteria? Does Django provide a way to do this?

Well, as our programming partner, YES. YES. YES, Django does allow us to create custom filters.

Example Use Case

Suppose you have a model like this:

Now, you want to create filters based on:

Room Range:
- 1 room, 2 rooms, 3 rooms, 4 or more rooms.
Building Age:
- Under Construction, Less than a year, 1 to 2 years, 3 to 4 years, 5 to 10 years, '11 to 15 years, 16 to 20 years, 21 to 25 years', 26 to 30 years, 30 years or more.

Most importantly, this involves specific ranges. The database stores these values as strings, but filtration needs to handle them as integers or floats.

Create a New File: `filter_utils.py`

To create a custom filter, Django provides the tools through django.contrib. Start by importing admin:

If you Ctrl + Click on the admin keyword, you will land in the admin module. Here, you’ll notice various types of filters Django offers.

Just focus on the filters section:

Now, I am gonna use SimpleListFilter so, if you again Ctrl + Click to explore this class on it you will get into the SimpleListFilter class and ListFilter

Now, If you explore these classes, you’ll find these methods and attributes:

Methods:

has_output
choices
queryset
expected_parameters
value

Attributes:

title
template
used_parameters
parameter_name
lookup_choices

we can use them in creating filters. I am not gonna cover all of them since I don't need all but if you wanna learn about them check this official documentation
https://docs.djangoproject.com/en/5.1/ref/contrib/admin/filters/

Now, let's do this

Room Range Filter

This is my RoomRangeFilter

Here,
title: This method returns a list of tuples where:

The first element is the coded value for the URL query.
The second element is the human-readable name for the filter option.

lookups: Returns a list of tuples. The first element in each tuple is the coded value for the option that will appear in the URL query. The second element is the human-readable name for the option that will appear in the right sidebar

queryset: Returns the filtered queryset based on the value provided in the query string and retrievable via`self.value()

When applied, this filter will look like this:

Building Age Filter

Another example is a BuildingAgeFilter

But here is a tricky part

Exclude empty and null values in your filter logic when needed.
Handle data type conversions (e.g., casting strings to integers) to ensure the filter works correctly

They all come from query set (self, request, queryset) function parameters.

If you wanna learn more about this check the official Django documentation.

Folder Structure

Conclusion

Django’s admin panel makes filtering super easy, but custom filters give you extra flexibility. Using SimpleListFilter, you can create filters that fit your needs perfectly. Just override methods like queryset and lookups, and you’re good to go.

Stay Connected - @syedamahamfahim 🐬

How to Create Custom Template Tags in Django?

Syeda Maham Fahim — Sun, 26 Jan 2025 22:24:58 +0000

If you have worked with Django, you must have used templates. Templates in Django are simply HTML files that can receive data from the views and display it on the website.

Basic Example of Django Template

Imagine you have an HTML template like this:

This template will get data from the view, like this:

In the example above, we have a template called courses where the data (like course names) is being passed from the views.py file. The output on the website will look like this:

Problem: Displaying Course Count

Now, let’s say you want to show the total number of courses on the website. You may think of adding the logic to the view, and that’s correct. You would do something like this in your views.py:

def course_list(request):
    total_courses = Course.objects.count()
    return render(request, 'courses.html', {'courses': courses, 'total_courses': total_courses})

But what if you have multiple pages on your website, like a blog page, author page, instructor page, and you want to display the course count on all of them?

You would need to add the logic in each of the views, and that can get messy. This is where template tags come in.

What is a Template Tag?

In simple terms:

A template tag in Django is a special kind of tag that allows you to add custom functionality within Django’s template system.

Template tags make it easier to reuse logic across different templates, without having to repeat the same code in your views.

Why Use Template Tags?

Let’s say you have a courses app where you want to display:

Total number of courses
Number of available courses
Number of enrolled students

Instead of adding this logic in each view, you can use template tags to make it easier.

Step 1: Create a Template Tag

Create the templatetags folder inside your courses app:

Your folder structure will look like this:

   courses/
       ├── templatetags/
           ├── __init__.py
           └── course_tags.py

Inside the course_tags.py file, define a template tag that will calculate and return the total number of courses, number of available courses, and number of enrolled students.

   from django import template
   from courses.models import Course

   register = template.Library()

   @register.simple_tag
   def total_courses():
       return Course.objects.count()

   @register.simple_tag
   def available_courses():
       return Course.objects.filter(is_available=True).count()

   @register.simple_tag
   def enrolled_students(course_id):
       course = Course.objects.get(id=course_id)
       return course.enrolled_students.count()

Step 2: Load and Use the Template Tags in Your Templates

Now, you can use these template tags in your HTML templates to display relevant data on different pages related to courses.

Example 1: Displaying Course Count on the Course List Page

In your course_list.html template, you can load the custom tags and use them to display the total number of courses and available courses.

{% load course_tags %}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Course List</title>
</head>
<body>
    <h1>All Courses</h1>

    <p>Total courses: {% total_courses %}</p>
    <p>Available courses: {% available_courses %}</p>

    <ul>
        {% for course in courses %}
            <li>{{ course.name }} - {{ course.description }}</li>
        {% endfor %}
    </ul>
</body>
</html>

This template will show:

The total number of courses.
The number of available courses.

Example 2: Displaying Enrolled Students on a Course Detail Page

For the course details page, you can use the enrolled_students template tag to show how many students are enrolled in a specific course.

{% load course_tags %}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>{{ course.name }}</title>
</head>
<body>
    <h1>{{ course.name }}</h1>
    <p>{{ course.description }}</p>

    <p>Enrolled students: {% enrolled_students course.id %}</p>

    <h2>Enroll Now</h2>
    <!-- Add enrollment form here -->
</body>
</html>

Here, the enrolled_students tag takes the course.id and returns the number of students enrolled in that specific course.

Benefits of Using Template Tags in This Example

Once you define a template tag (like total_courses, available_courses, or enrolled_students), you can use it in multiple places across your app without repeating the same logic in each view.
If you want to change how the course count is calculated (e.g., if you add a new filter for "active" courses), you only need to update the tag, not every view or template.

Final Output

Conclusion

In this blog post, we used template tags in Django to avoid adding repetitive logic for counting courses and students in each view. Instead of manually passing the data from views, we created reusable template tags that can be used across multiple templates in the courses app.

Stay Connected - @syedamahamfahim 🐬

How to disable admin editing in the Django Admin Panel

Syeda Maham Fahim — Sun, 26 Jan 2025 20:09:59 +0000

Not gonna lie, the Django Admin Panel is super helpful for managing models, data, and users directly from a user-friendly interface. You don’t have to create advanced search and filtration features from scratch—it’s already built-in!

But what if you want to restrict editing for certain models or fields?

Sometimes, allowing editing in the Admin Panel isn’t the best idea, especially when:

The data needs to remain consistent and shouldn’t be modified accidentally.
You only want to display data without adding or editing it.

Real-Life Scenario

Recently, one of my clients needed a way to view data with filtration and pagination. The data was scraped from another website, and the client wanted an easy way to track new property listings.

For this, I decided to use Django. It gave me a simple way to manage and display the data without the hassle of creating custom pages.

Take a look at the screenshots:

Admin Panel Overview:

Here, the admin panel only shows Import/Export options. There’s no way to add or edit data from the admin panel.

Individual Page:

The individual entry pages also don’t have any edit options.

Now, let me show you how to set this up in Django.

Steps to Disable Editing

1. Define Your Model

Here’s an example of the model I used:

from django.db import models

class Property(models.Model):
    name = models.CharField(max_length=255)
    price = models.IntegerField()
    location = models.CharField(max_length=255)
    date_listed = models.DateField()

    def __str__(self):
        return self.name

This model is used to store property data scraped from the external website.

2. Customize the Admin Panel

To disable editing, simply override two functions in your admin.py:

has_add_permission: Disables adding new entries.
has_change_permission: Disables editing existing entries.

Here’s how the admin.py looks:

from django.contrib import admin
from .models import Property

class ReadOnlyAdmin(admin.ModelAdmin):
    list_display = ('name', 'price', 'location', 'date_listed')  # Fields to display

    def has_add_permission(self, request):
        return False  # Disable adding new entries

    def has_change_permission(self, request, obj=None):
        return False  # Disable editing existing entries

admin.site.register(Property, ReadOnlyAdmin)

I’ve also used a base class here to manage list_display for better data presentation.

What Does This Do?

No Add Option

The “Add” button is removed from the admin panel.
No Edit Option

When you click on an entry, it opens in read-only mode, without any save buttons.

This setup is perfect for situations where:

You only want to display data.
Editing and adding entries isn’t necessary or could cause issues.

Why Is This Useful?

Preserve Data Integrity: If the data comes from an external source (like scraping or APIs), it’s better to avoid manual editing in the admin panel to ensure consistency.

-Read-Only Views for Reference Data:

Sometimes, the admin panel is just used for viewing or filtering data. For example, analytics dashboards, property listings, or logs.

Conclusion

Disabling editing in Django Admin is super easy and incredibly useful when you need to protect or display data without allowing accidental changes.

Follow the steps above, and you’ll have a secure, read-only admin panel ready in no time.

Stay Connected - @syedamahamfahim 🐬

How to Reset PostgreSQL Password

Syeda Maham Fahim — Fri, 24 Jan 2025 22:19:11 +0000

I'm writing this article because I recently ran into an issue with PostgreSQL where I had to reset the password. The steps are simple, but if you’re new to PostgreSQL or running it on Windows, it might get tricky. So, let’s break it down into clear steps that are easy to follow.

Step 1: Stop the PostgreSQL Service

First, we need to stop the PostgreSQL service before we can reset the password. Here’s how you do that:

Press Win + R, type services.msc, and hit Enter.

Look for PostgreSQL in the list.
Right-click on it and choose Stop.

Step 2: Start PostgreSQL in Single-User Mode

Now, we’ll start PostgreSQL in single-user mode. This mode allows us to reset the password without needing the current one.

Open Command Prompt as an administrator.

To do this, press Win + S, type cmd, right-click on Command Prompt, and choose Run as administrator.
Now, navigate to the PostgreSQL bin directory where the executable is located. Typically, it’s in:

  cd "C:\Program Files\PostgreSQL\16\bin"

After that, run PostgreSQL in single-user mode with this command:

  postgres --single -D "C:\Program Files\PostgreSQL\16\data" postgres

Note: Replace "C:\Program Files\PostgreSQL\16\data" with your actual data directory path if it’s different.

Step 3: Reset the Password

Once PostgreSQL starts in single-user mode, you’ll see a prompt where you can run SQL commands. To reset the password for the postgres user, use this command:

ALTER USER postgres WITH PASSWORD 'your_new_password';

Replace 'your_new_password' with the new password you want to set.

After entering the command, press Enter to reset the password.

Step 4: Restart the PostgreSQL Service

After resetting the password, exit the single-user mode by closing the Command Prompt window. Then, go back to the Services tool:

Right-click on PostgreSQL and choose Start to restart the service.

Step 5: Reconnect with pgAdmin

Finally, open pgAdmin 4 (or any other PostgreSQL client you use) and try connecting with the new password.

If it still doesn’t work, you may need to update the saved password:

Right-click on the server in the Object Browser.
Choose Properties → Connection.
Enter the new password and click Save.

Simplified Process (For Quick Reference)

In simpler terms, here’s what you need to do:

Stop PostgreSQL: Go to services.msc and stop PostgreSQL.
Open Command Prompt as Admin: Search for cmd, right-click, and run as administrator.
Navigate to PostgreSQL Folder: Use this command:

   cd "C:\Program Files\PostgreSQL\16\bin"

Run PostgreSQL in Single-User Mode:

   postgres --single -D "C:\Program Files\PostgreSQL\16\data" postgres

Reset the Password:

   ALTER USER postgres WITH PASSWORD 'your_new_password';

Restart PostgreSQL: Go back to Services and start PostgreSQL again.
Reconnect with pgAdmin: Use the new password to connect.

Final Thoughts

I hope this guide makes it easy for you to reset your PostgreSQL password on Windows using single-user mode. It’s a lifesaver when you’re locked out of your database.

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Stay connected - @syedamaham.dev 🐬
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Forem: Syeda Maham Fahim

How to Import/Export CSV file in pgAdmin

Importing CSV into pgAdmin

Excluding Unwanted Columns

Exporting CSV from pgAdmin

Accessing the Exported CSV

Conclusion

How to Generate and Use SSH Keys In Windows

PuTTY

1. Installing PuTTY

2. Open PuTTY

3. Generate an SSH Key

4. Save Your SSH Keys

5. Regenerate Public Key from Private Key

6. Connect to a Server Using Your SSH Key

Final Thoughts

How to create a custom filter in Django Admin/CMS

Example Use Case

Create a New File: filter_utils.py

Room Range Filter

Building Age Filter

Folder Structure

Conclusion

Stay Connected - @syedamahamfahim 🐬

How to Create Custom Template Tags in Django?

Basic Example of Django Template

Problem: Displaying Course Count

What is a Template Tag?

Why Use Template Tags?

Step 1: Create a Template Tag

Step 2: Load and Use the Template Tags in Your Templates

Example 1: Displaying Course Count on the Course List Page

Example 2: Displaying Enrolled Students on a Course Detail Page

Benefits of Using Template Tags in This Example

Final Output

Conclusion

How to disable admin editing in the Django Admin Panel

Real-Life Scenario

Admin Panel Overview:

Individual Page:

Steps to Disable Editing

1. Define Your Model

2. Customize the Admin Panel

What Does This Do?

Why Is This Useful?

Conclusion

How to Reset PostgreSQL Password

Step 1: Stop the PostgreSQL Service

Step 2: Start PostgreSQL in Single-User Mode

Step 3: Reset the Password

Step 4: Restart the PostgreSQL Service

Step 5: Reconnect with pgAdmin

Simplified Process (For Quick Reference)

Final Thoughts

Create a New File: `filter_utils.py`