DbContext/QuoteDbContext.cs

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

public class QuoteDbContext : DbContext
{
    public DbSet<Quote> Quotes { get; set; }

    // Constructor
    public QuoteDbContext(DbContextOptions<QuoteDbContext> options) : base(options)
    {
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        // Configure the Quote entity using Fluent API
        modelBuilder.Entity<Quote>(entity =>
        {
            entity.HasKey(q => q.Id);  // Primary key

            // Configure indexed columns
            entity.HasIndex(q => q.Author);
            entity.HasIndex(q => q.QuoteText).IsUnique();

            // Column length and constraints are defined using Data Annotations,
            // but Fluent API can also be used if needed.
            entity.Property(q => q.Author).IsRequired().HasMaxLength(255);
            entity.Property(q => q.QuoteText).IsRequired().HasMaxLength(1000);
            entity.Property(q => q.Source).HasMaxLength(255);
            entity.Property(q => q.Book).HasMaxLength(255);
            entity.Property(q => q.Categories).HasMaxLength(255);
            entity.Property(q => q.Url).HasMaxLength(500);
            entity.Property(q => q.Isbn).HasMaxLength(13);
            entity.Property(q => q.Language).HasMaxLength(50);
            entity.Property(q => q.OriginalLanguage).HasMaxLength(50);
        });
    }
}

public class Quote
{
    public int Id { get; set; }  // Primary key with auto-increment

    [Required]
    [MaxLength(255)]
    public string Author { get; set; }  // Indexed column

    [Required]
    [MaxLength(1000)]
    [Column("quote")]
    public string QuoteText { get; set; }  // Indexed and unique column

    [MaxLength(255)]
    public string? Source { get; set; }  // Nullable column

    [MaxLength(255)]
    public string DataSet { get; set; }

    [MaxLength(255)]
    public string? Book { get; set; }  // Nullable column

    [MaxLength(255)]
    public string? Categories { get; set; }  // Nullable column

    [MaxLength(500)]
    public string? Url { get; set; }  // Nullable column

    [MaxLength(13)]
    public string? Isbn { get; set; }  // Nullable column

    [MaxLength(50)]
    public string? Language { get; set; }  // Nullable column

    [MaxLength(50)]
    [Column("original_language")]
    public string? OriginalLanguage { get; set; }  // Nullable column

    [Column("created_at")]
    public DateTime DateCreated { get; set; } = DateTime.Now;  // Default to current datetime
}