In the eighteen years that I’ve been doing Web development, a lot has changed. We started out creating HTML pages to present static information to our users. We then used classic ASP to get database data and incorporate that into our pages. To use both of these technologies, we had to know a lot about HTML, CSS, and JavaScript. Along came .NET and we started rendering everything on the server-side. We forgot a lot about HTML, CSS, and JavaScript as Web Forms wrapped up a lot of that for us. Web Forms’ architecture closely mimicked the way developers created desktop applications. This was great for helping developers move to the Web, but unfortunately hid a lot of the power of the Web, and also tended to be a little slow.
public class ExampleContext : DbContext
{
public DbSet<Person> People { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder options)
{
options.UseModel(CompiledModelsExample.ExampleContextModel.Instance);
options.UseSqlServer("Server=(localdb)\\mssqllocaldb;Database=Test;Trusted_Connection=True;");
}
} CLI: dotnet ef dbcontext optimize -c ExampleContext -o CompliledModels -n CompiledModelsExample Package Manager Console: Optimize-DbContext -Context ExampleContext -OutputDir CompiledModels -Namespace CompiledModelsExample
options.UseModel(CompiledModelsExample.ExampleContextModel.Instance);
dotnet new webapi -o WebService
dotnet sln add WebService/WebService.csproj
dotnet add Web/Web.csproj reference DataLayer/DataLayer.csproj
cd YourFolder
dotnet add package Microsoft.EntityFrameworkCore.Design
dotnet tool update --global dotnet-ef dotnet ef migrations --startup-project WebService/ add Init -p DataLayer --context SqlServerContext dotnet ef --startup-project WebService/ database update Init -p DataLayer --context SqlServerContext
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Console;
namespace EFLogging
{
public class BloggingContextWithFiltering : DbContext
{
// It is very important that applications do not create a new ILoggerFactory instance for each context instance.
// Doing so will result in a memory leak and poor performance.
public static readonly LoggerFactory MyLoggerFactory
= new LoggerFactory(new[]
{
new ConsoleLoggerProvider((category, level)
=> category == DbLoggerCategory.Database.Command.Name
&& level == LogLevel.Information, true)
});
public DbSet<Blog> Blogs { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
=> optionsBuilder
.UseLoggerFactory(MyLoggerFactory) // Warning: Do not create a new ILoggerFactory instance each time
.UseSqlServer(
@"Server=(localdb)\mssqllocaldb;Database=EFLogging;Trusted_Connection=True;ConnectRetryCount=0");
}
} 
SqlCommand cmd=new SqlCommand ("select count(*) from login where user='"+userName+"' and pass='"+password+"'",con); select count(*) from login where user='admin' and pass='salam123'
' or 1=1 --
select count(*) from login where user='admin' and pass='' or 1=1 --'
SqlCommand cmd=new SqlCommand ("select count(*) from login where user=@u and pass=@p",con);
cmd.Parameters.Add("@u", SqlDbType.Varchar, 10).Value=TextLogin.Text.Trim();
cmd.Parameters.Add("@p", SqlDbType.Varchar,10).Value=TextPwd.Text.Trim(); string, int?, byte[]
int, decimal, bool, DateTime
[Required]
public string Url { get; set; } protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Blog>()
.Property(b => b.Url)
.IsRequired();
} public string FirstName { get; set; } [StringLength(450)]
public string FirstName { get; set; }
[MaxLength(450)]
public string LastName { get; set; }
[MaxLength]
public string Address { get; set; } modelBuilder.Entity<Person>() .Property(x => x.Address) .HasMaxLength(450);
modelBuilder.Entity<Person>()
.Property(x => x.Address)
.HasColumnType("nvarchar(max)"); [Column(TypeName = "varchar")]
[MaxLength]
public string Address { get; set; }
Data type 'varchar' is not supported in this form. Either specify the length explicitly in the type name, for example as 'varchar(16)', or remove the data type and use APIs such as HasMaxLength to allow EF choose the data type.
[Column(TypeName = "varchar(max)")]
public class Person
{
public int Id { set; get; }
public DateTime? DateAdded { set; get; }
public DateTime? DateUpdated { set; get; }
[StringLength(450)]
public string FirstName { get; set; }
[MaxLength(450)]
public string LastName { get; set; }
//[Column(TypeName = "varchar")]
[MaxLength]
public string Address { get; set; }
//bit
public bool IsActive { get; set; }
//tiny Int
public byte Age { get; set; }
//small Int
public short Short { get; set; }
//int
public int Int32 { get; set; }
//Big int
public long Long { get; set; }
} 
CREATE TABLE [dbo].[Persons]( [DateAdded] [datetime2](7) NULL, [DateUpdated] [datetime2](7) NULL,
[ConcurrencyCheck]
public string Name { set; get; } modelBuilder.Entity<Person>()
.Property(p => p.Name)
.IsConcurrencyToken(); [Timestamp]
public byte[] Timestamp { get; set; } modelBuilder.Entity<Blog>() .Property(p => p.Timestamp) .ValueGeneratedOnAddOrUpdate() .IsConcurrencyToken();
public class Car
{
public string Id { get; set; } public class Car
{
public string CarId { get; set; } public class Car
{
[Key]
public string LicensePlate { get; set; } public class MyContext : DbContext
{
public DbSet<Car> Cars { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Car>()
.HasKey(c => c.LicensePlate);
}
} {
"dependencies": {
"System.ComponentModel.Annotations": "4.1.0"
}
} protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Car>()
.HasKey(c => new { c.State, c.LicensePlate });
} public class Blog
{
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int BlogId { get; set; }
public string Url { get; set; }
} protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Blog>()
.Property(b => b.BlogId)
.ValueGeneratedNever();
} public class Blog
{
public int BlogId { get; set; }
public string Url { get; set; }
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public DateTime Inserted { get; set; }
} protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Blog>()
.Property(b => b.Inserted)
.ValueGeneratedOnAdd();
} protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Blog>()
.Property(b => b.Inserted)
.HasDefaultValueSql("getdate()");
} public class Blog
{
public int BlogId { get; set; }
public string Url { get; set; }
[DatabaseGenerated(DatabaseGeneratedOption.Computed)]
public DateTime LastUpdated { get; set; }
} protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Blog>()
.Property(b => b.LastUpdated)
.ValueGeneratedOnAddOrUpdate();
} public class Person
{
public int PersonId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string DisplayName { get; set; }
}
public class MyContext : DbContext
{
public DbSet<Person> People { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Person>()
.Property(p => p.DisplayName)
.HasComputedColumnSql("[LastName] + ', ' + [FirstName]");
}
} protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.HasSequence<int>("OrderNumbers", schema: "shared")
.StartsAt(1000).IncrementsBy(5);
modelBuilder.Entity<Order>()
.Property(o => o.OrderNo)
.HasDefaultValueSql("NEXT VALUE FOR shared.OrderNumbers");
} protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.HasSequence<int>("PrimaryKeyWithSequenceSequence");
modelBuilder.Entity<PrimaryKeyWithSequence>(entity =>
{
entity.Property(e => e.PrimaryKeyWithSequenceId).HasDefaultValueSql("NEXT VALUE FOR [PrimaryKeyWithSequenceSequence]");
});
} protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Blog>()
.HasIndex(b => b.Url)
.HasName("Index_Url"); modelBuilder.Entity<Blog>().HasIndex(b => b.Url).HasName("Index_Url").IsUnique(); modelBuilder.Entity<Person>()
.HasIndex(idx => new { idx.FirstName, idx.LastName })
.IsUnique(); protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Car>()
.HasAlternateKey(c => c.LicensePlate)
.HasName("AlteranteKey_LicensePlate");
} modelBuilder.Entity<Person>()
.HasAlternateKey(x => new { x.FirstName, x.LastName }); table.UniqueConstraint("AK_Persons_FirstName_LastName", x => new { x.FirstName, x.LastName }); PM> Install-Package RavenDB.Embedded -Pre
var documentStore = new EmbeddableDocumentStore { DataDirectory = @"~/app_data/ravendb" };
documentStore.Initialize(); <connectionStrings> <add name="Local" connectionString="DataDir = ~\Data"/>
var documentStore = new EmbeddableDocumentStore{RunInMemory = true}.Initialize() NonAdminHttp.EnsureCanListenToWhenInNonAdminContext(8080); // Start the HTTP server manually var server = new RavenDbHttpServer(documentStore.Configuration, documentStore.DocumentDatabase); server.Start();
d:\ravendb\server> .\raven.server.exe /install
d:\ravendb\server> .\raven.server.exe /uninstall
PM> Install-Package RavenDB.AspNetHost -Pre