22 Jan 2025 #csharp #todayilearned
TL;DR: For nullable columns with default constraints, you have to tell EntityFramework the default value of the mapping property via C#. Otherwise, when you create a new record, it will have NULL instead of the default value in the database. You’re welcome! Bye!
Let’s create a dummy table with one nullable column but with a defualt constraint
Let’s create a new Movies database with one table called Movies, with an Id, a name, and a director name as optional, but with a default value. Like this,
CREATE DATABASE Movies;
GO
USE Movies;
GO
CREATE TABLE Movies (
Id INT PRIMARY KEY IDENTITY(1,1),
Name NVARCHAR(100) NOT NULL,
DirectorName NVARCHAR(100) DEFAULT 'ThisIsADefaultValue'
);
GO
Let’s create a new record (without the nullable column) and read it back
Now to prove a point, let’s use EntityFramework Core to insert a new movie without passing a director name and read it back.
What will be the value of DirectorName once we read it back? Null? The value inside the default constraint? Make your bets!
Here we go,
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
namespace TestProject1;
[TestClass]
public class EntityFrameworkAndDefaults
{
[TestMethod]
public void TestInsertAndReadMovie()
{
const string connectionString = $"Server=(localdb)\\MSSQLLocalDB;Database=Movies;Trusted_Connection=True;";
var dbContextOptions = new DbContextOptionsBuilder<MoviesContext>()
.UseSqlServer(connectionString)
.Options;
using (var context = new MoviesContext(dbContextOptions))
{
var inception = new Movie
{
Name = "Inception"
// No director name here...
// ^^^^^
};
context.Movies.Add(inception);
context.SaveChanges();
}
using (var context = new MoviesContext(dbContextOptions))
{
var movie = context.Movies.FirstOrDefault(m => m.Name == "Inception");
Assert.IsNotNull(movie);
Assert.AreEqual("ThisIsADefaultValue", movie.DirectorName);
// ^^^^^^^^
// Assert.AreEqual failed. Expected:<ThisIsADefaultValue>. Actual:<(null)>.
//
// Whaaaaat!
}
}
}
public class MoviesContext : DbContext
{
public DbSet<Movie> Movies { get; set; }
public MoviesContext(DbContextOptions<MoviesContext> options)
: base(options)
{
}
}
public class Movie
{
public int Id { get; set; }
public required string Name { get; set; }
public string? DirectorName { get; set; }
}
Ok, to my surprise that test fails. movie.DirectorName isn’t "ThisIsADefaultValue". It’s null.
I was expecting to see the value from the default constraint in the database. But, no. Wah, wah, wah, Wahhhhhhh…
Here you have it EntityFramework. Can I get my default value now?
We have to tell EntityFramework Core the default value of our column, like this,
public class MoviesContext : DbContext
{
public DbSet<Movie> Movies { get; set; }
public MoviesContext(DbContextOptions<MoviesContext> options)
: base(options)
{
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
// For simplicity, let keep it here...
modelBuilder.Entity<Movie>(entity =>
{
entity
.Property(e => e.DirectorName)
.HasDefaultValueSql("ThisIsADefaultValue");
// ^^^^^
// Here you have it EntityFramework Core
// Can I get my default value now?
});
}
}
This behavior only adds up to my love and hate relationship with EntityFramework Core.
Et voilà!
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21 Jan 2025 #career
AI is here to stay. We can’t deny that.
One day, will AI become self-conscious and try to exterminate us all? Who knows. That’s another discussion.
But we, as coders, have to adapt, as we always have, and adopt AI.
Today, I had a conversation with a group of ex-coworkers.
One of the members shared he was asked to finish almost an entire working app as part of a take-home coding challenge for an interview process at a startup. He was given only 5 hours. We all agreed that 5 hours wasn’t enough.
Someone else said he should have used AI. But he refused to use AI.
Maybe the intention behind that take-home challenge was to use AI and come up with a decent working prototype quickly. Who knows? Companies aren’t that clear with their interview process. And hiring is broken.
But we can’t refuse to use AI.
AI is here to make us more efficient.
What used to take days, now it only takes hours or minutes. By pressing a button, we compile thousands of source files in just seconds. Refusing to use AI is like refusing to use calculators or spreadsheets for accounting. It’s like refusing to travel by plane or drive a car.
These days when efficiency and productivity are rewarded, AI is a game-changer.
We can’t pretend to keep using punch cards and computers that fill an entire room. AI is the future. And we have to adapt. Coding in 2034 will change. But, one thing is certain: we can’t use AI to replace our thinking. We should be the pilots, and AI as our copilot.
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20 Jan 2025 #books #writing
What’s the first thing that comes to your mind when you hear “writer”?
Probably it’s a starving artist isolated in a cabin, in the middle of nowhere, typing the next award-winning best-selling novel on an old typewriter, holding a cigar.
The truth is you don’t have to be a “writer” to write.
That’s the main lesson from “Writing to Learn” by William Zinsser. Here are five lessons I learned from that book—in five quotes:
1. “Contrary to general belief, writing isn’t something that only “writers” do; writing is a basic skill for getting through life.”
A CV, a cover letter, an email for a client, a request for time off, and a resignation email. What do they all have in common? Writing!
And that’s only thinking of an employee in a full-time job. But writing is everywhere else.
2. “Writing organizes and clarifies our thoughts”
If you want to check if you know a subject well enough, try to explain it and even better, write about it.
When you write you need a message, a chain of thoughts, and a reader persona. You need the right words and the right amount of them. The act of writing solidifies your understanding and shows you your gaps.
Writing is thinking.
3. “Writing is learned mainly by imitation”
Writers are readers too.
And noticing your behavior as a reader is your cheat code to better writing. Notice your favorite passages from the books you read, the posts you read until the end, the social media posts that make you stop scrolling. How did they grab your attention? What title did they use? Why did they make you read?
If you need a writing mentor, hand-copy your favorite writer and find patterns in their writing.
4. “The hard part isn’t the writing, the hard part is the thinking”
There’s writing to share information and writing to discover what we want to say.
When you write to share information, you need to ask yourself, “what do I want to say?” And when you write to discover what to say, you’re free to leave questions without answers and to build up from an answer you don’t have yet.
Either type of writing makes you think clearly.
5. “Non-fiction writing should always have a point: it should leave the reader with a set of facts, or an idea, or a point of view, that he didn’t have when he started reading”
Can this benefit one person?
That’s the best guideline to decide what to write. If it can benefit one person, you can write lessons, stories, rants, mistakes, questions, and predictions… Anything!
If it can benefit one person, you’re safe to write. And that one person can be your past self.
You don’t need to be an expert to write. Who’s an expert anyway? You don’t need to be famous either. Share what you have learned. Share what you’re learning. Share what inspires you. You don’t need to be a writer for that. Write! Probably the next time you’re Googling something you’ll find your own writing.
19 Jan 2025 #books
Ideas are the new currency of the 21st century.
If you’re familiar with James Altucher’s work, you know about becoming an Idea Machine by writing 10 bad ideas a day.
But “Choose Yourself Guide to Wealth” takes the Idea Machine concept further, covering how to turn your ideas into reality.
Here are four lessons I learned from reading “Choose Yourself Guide to Wealth”:
1. Don’t do to-do lists
To-do lists are stressful.
Anything on a to-do list is something you haven’t done and probably never will do. In the meantime, it’s only causing stress.
I have items in one of my multiple to-do lists from years ago. I haven’t done anything about them yet. Oops!
Instead of to-do lists and goals, live by themes.
If you need inspiration to choose your own theme, follow the Daily Practice: Do something for your physical, emotional, spiritual, and mental well-being every day.
That’s the only rule I’ve followed since I read this book.
2. Become an idea machine
You don’t need chains to feel like a slave.
When you work on somebody else’s ideas, you’re a slave. Being an employee means working on somebody else’s ideas. Therefore, being an employee is being an idea slave, even if those ideas are good.
To be free and successful, come up with ideas every day. If any of your projects fail, come up with a list of ideas to improve it.
“I think of ideas for other companies who call me, and my ‘business’ is to help them implement those ideas on their own and become massive successes”
3. Be a good salesman and negotiator
To make others follow your ideas, you need to be a good salesman and negotiator.
But sales and negotiation aren’t about closing tactics or Jedi mind tricks.
We do business with people we like and trust. So you need to be friends with your buyers. You need to care about the same things they do. You need to sell and negotiate with people you love because a bad client can make you and the people around you miserable.
“One of the best ways of making friends and customers for life is to direct them to a better service or product than yours”
When in doubt, outsource your negotiation to the other side. “Hey, I’m new to this negotiation thing. I need your advice. What would you do if you were in my shoes?”
After a good sale, everybody should be happy.
4. Invest in yourself and in experiences
Don’t day trade or invest in mutual funds.
Have enough cash to sleep well at night. Don’t invest all your money in one place and only invest with people smarter than you.
Start your own business and invest in experiences and books.
Parting Thought
Ideas can change your life.
If you don’t know where to start to change it, work on your health. Start by writing ideas to improve your health.
In 2024, after burnout and a layoff, to get my life back on track I focused on my health by waking up early, working out, writing 200 words, and removing negativity from my life. I remember 2024 as the year when I was the healthiest.
Adopt your own Daily Practice. Ask yourself, “What I can do to keep my physical, emotional, spiritual, and mental bodies healthy?” and see how your life changes.
18 Jan 2025 #misc
We all want to know what we know now but ten years ago.
That’s how this Reddit AMA felt when I read it. Len, a 102-year-old WW2 veteran, sat with his grandson to answer questions about history, WW2, and life in general. His grandson, who did the writing part, wanted to hear more of Grandpa’s stories.
These are my favorite answers and quotes.
“War Is Never Necessary. There Is No Such Thing as a Justified War”
Len served with the Canadian troops in the liberation of the Netherlands in 1939. Nazis were trying to reach Copenhagen.
After many years, Len has overcome traumas thanks to his wife and family’s support. But there are memories he can’t erase and, even to this day, he has bad dreams about it. He still remembers his service number – Eight-one-two-four-zero, by the way – and the D-Day is still vivid in his mind. He can’t even watch the landing scene from Saving Private Ryan.
[About D-Day] I just thought “I have a job to do”. Analyze the situation and react. If you stop, dig a hole. You don’t say “I think this is ok” you dig down deeper. Don’t go hunting for souvenirs in a minefield.
Someone in the comments shared the story of her young grandmother during those war times. She and her class learned and sang the Canadian national anthem to the soldiers. She even refused to wear a green hair ribbon to school because the Canadian flag was red.
“We had no idea that the Holocaust was happening. We saw three emaciated people walking in striped pajamas with big smiles on their faces. They had been liberated. That was the first time I learned about the atrocities that had been committed. In some of the media portrayals, this isn’t the case.”
“War should NOT happen. Surely there is a lesson. Don’t let it happen again.”
“Don’t Drink, Don’t Smoke, and Common Sense”
That was what Len answered when someone asked about what to do to live to such an amazing age.
His secret for a good life? “Non-smoker, non-drinker, and not necessarily following all the trends. Do your own thing.”
The higher we climb the mountain of life, the more perspective and the better view we have. From Len’s 102-year-old perspective:
A perfect day? “Waking up and being alive… A nice visit. A nice conversation with someone. And some tea.”
To enjoy each day to the fullest? “Surround yourself with people that you love. Take a minute to step back and see all the beauty around you.”
“People have forgotten the value of life. People focus too much on possessions and not the people and beauty that surrounds them.”
“During the Depression There Was NO Money”
Len has witnessed the adoption of cars, computers, and cell phones, but more shocking: he lived through the Great Depression.
Apart from pictures and history textbooks, we have no idea of an economic event of such proportions. Just last week (the first week of August 2024, if you’re reading this from the future), the US Stock Market fell between 10% and 20% and we called it “Black Monday” and were afraid of another recession. But here’s what Len shared when he was asked about the Great Depression:
“There’s no way of comparing that. During the Depression, there was NO money. I knew a man who hauled wood by horse to the school. A day’s work got you one dollar. We were okay, we had lots of vegetables and chickens. No use selling a cow because you would only get a dollar so you kept it for meat and milk. There is no comparison.”
Are You Scared To Die? –”No. It Happens to Everyone”
“If I could give myself advice I would say stay away from controversy. If something works stick with it.”
When asked what young people today should understand: “The value of life. Don’t louse it up.”
“T.V. is a pain in the neck. Interesting. Informative. Unnecessary.” Oh boy! I wished he had answered when and how he learned this one.
“Important: integrity and honesty. Unimportant: Money”
When asked about fearing death: “Not a bit. Lived a good life, what else do you want. No. Nothing wrong with dying.”
A 40-something asked about what waking up at 102 looks like: “Everything hurts, but I am not suffering.”
“Take care of your body. You only get one.” “Don’t smoke.”
This AMA was full of wisdom. But my favorite answer is when someone asked Len what he wanted to do when he grew up: “Happy.”
I can only imagine how fulfilled he has lived all these years to say at 102 he’s not afraid of death. What a wonderful life!