I'm trying to wrap basic actions fro model(like get by id, etc.) in repositories. However I'm facing with two problems:
1. Connection String : Is there any solution to put it in config, and not to hard code it in class, like I did?
public const string ConnectionString = "Server = (localdb)\\mssqllocaldb;Database=pinchdb;Trusted_Connection=True;MultipleActiveResultSets=true";// can I get rid of it?
public DbSet<Department> Departments { get; set; }
public DbSet<Employee> Employees { get; set; }
public DbSet<Project> Projects { get; set; }
public DbSet<ProjectDepartments> ProjectsDepartments { get; set; }
public DbSet<Roles> Roles { get; set; }
public effMercContext(DbContextOptions<effMercContext> options)
: base(options)
{
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<ProjectDepartments>()
.HasKey(t => new { t.ProjectId, t.DepartmentId });
modelBuilder.Entity<ProjectDepartments>()
.HasOne(pt => pt.Project)
.WithMany(p => p.ProjectDepartment)
.HasForeignKey(pt => pt.ProjectId);
modelBuilder.Entity<ProjectDepartments>()
.HasOne(pt => pt.Department)
.WithMany(t => t.ProjectDepartment)
.HasForeignKey(pt => pt.DepartmentId);
}
}
public class EffMercDbContextFactory : IDbContextFactory<effMercContext>
{
public effMercContext Create(DbContextFactoryOptions options)
{
var builder = new DbContextOptionsBuilder<effMercContext>();
builder.UseSqlServer("Server=(localdb)\\mssqllocaldb;Database=pinchdb;Trusted_Connection=True;MultipleActiveResultSets=true");
return new effMercContext(builder.Options);
}
}
2. Can I call Dbcontext without options to implement methods?
public Employee GetByID(int id)
{
var optionsBuilder = new DbContextOptionsBuilder<effMercContext>();// how can I get rid of this and just call effMercContext
optionsBuilder.UseSqlServer(effMercContext.ConnectionString);
using (effMercContext db = new effMercContext(optionsBuilder.Options))
{
return db.Employees.Where(x => x.Id == id).FirstOrDefault();
}
}
You can put your connectionstring in appsettings.json as shown below.
Also, you can have config transforms for the appsettings.json based on the environments.
in the Startup.cs
Access the above config while creating the DbContext.
services.AddDbContext<ApplicationDbContext>(
options =>
options.UseSqlServer(
configuration["Data:DefaultConnection:ConnectionString"], b =>
b.MigrationsAssembly("MyProj.Web"))
Add a default constructor to effMercContext. Then you shouldn't need to pass DbContextOptions.
Related
I've got the following problem:
I'm using NPGSQL for the Connection to the Database. Furthermore I'm using Entity Framework Core.
This is how my Context looks like:
using System.IO;
using DatabaseLibrary.Models.Discount;
using DatabaseLibrary.Models.Gender;
using DatabaseLibrary.Models.Ranks;
using DatabaseLibrary.Models.Employee;
using DatabaseLibrary.Models.Items;
using DatabaseLibrary.Models.Settings;
using DatabaseLibrary.Models.Transaction;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
namespace DatabaseLibrary
{
// ReSharper disable once InconsistentNaming
public class PGSQLConnectionManager : DbContext
{
//Variables
private IConfiguration Configuration { get; }
//public PGSQLConnectionManager(DbContextOptions<PGSQLConnectionManager> options) : base(options)
//{
// Configuration = (new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.Development.json").Build());
//}
public PGSQLConnectionManager()
{
Configuration = (new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.Development.json").Build());
}
public PGSQLConnectionManager(IConfiguration configuration)
{
Configuration = configuration;
}
//Database
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
=> optionsBuilder.UseNpgsql(
Configuration["ConnectionStrings:PGSQLConnectionManager"]
);
//Model Sets
public DbSet<Gender> Gender { get; set; }
public DbSet<Gender2Employee> Gender2Employee { get; set; }
public DbSet<EmployeeRank> EmployeeRank { get; set; }
public DbSet<Employee> Employee { get; set; }
public DbSet<Item> Item { get; set; }
public DbSet<ItemType> ItemType { get; set; }
public DbSet<ItemType2Item> ItemType2Items { get; set; }
public DbSet<EmployeeRank2Employee> EmployeeRank2Employees { get; set; }
public DbSet<Transaction> Transactions { get; set; }
public DbSet<Transaction2Items> Transaction2Items { get; set; }
public DbSet<TransactionNonItem> TransactionNonItem { get; set; }
public DbSet<TaxSettings> TaxSettings { get; set; }
public DbSet<Discount> Discount { get; set; }
public DbSet<Transaction2Discount> Transaction2Discount { get; set; }
public DbSet<EmployeeRank2AspRole> EmployeeRank2AspRoles { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Gender>().ToTable("Gender");
modelBuilder.Entity<Gender2Employee>().ToTable("Gender2Employee");
modelBuilder.Entity<EmployeeRank>().ToTable("EmployeeRank");
modelBuilder.Entity<Employee>().ToTable("Employee");
modelBuilder.Entity<EmployeeRank2Employee>().ToTable("EmployeeRank2Employee");
modelBuilder.Entity<Item>().ToTable("Item");
modelBuilder.Entity<ItemType>().ToTable("ItemType");
modelBuilder.Entity<ItemType2Item>().ToTable("ItemType2Item");
modelBuilder.Entity<Transaction>().ToTable("Transaction");
modelBuilder.Entity<Transaction2Items>().ToTable("Transaction2Items");
modelBuilder.Entity<TransactionNonItem>().ToTable("TransactionNonItem");
modelBuilder.Entity<TaxSettings>().ToTable("TaxSettings");
modelBuilder.Entity<Discount>().ToTable("Discount");
modelBuilder.Entity<Transaction2Discount>().ToTable("Transaction2Discount");
modelBuilder.Entity<EmployeeRank2AspRole>().ToTable("EmployeeRank2AspRole");
/*
* Primary Key auto increment
*/
modelBuilder.Entity<Gender>()
.Property(g => g.GenderId)
.UseIdentityColumn();
modelBuilder.Entity<Gender2Employee>()
.Property(g => g.Gender2EmployeeId)
.UseIdentityColumn();
modelBuilder.Entity<Item>()
.Property(i => i.ItemId)
.UseIdentityColumn();
modelBuilder.Entity<ItemType>()
.Property(it => it.ItemTypeId)
.UseIdentityColumn();
modelBuilder.Entity<ItemType2Item>()
.Property(iti => iti.ItemType2ItemId)
.UseIdentityColumn();
modelBuilder.Entity<EmployeeRank>()
.Property(er => er.EmployeeRankId)
.UseIdentityColumn();
modelBuilder.Entity<EmployeeRank2Employee>()
.Property(ere => ere.EmployeeRank2EmployeeId)
.UseIdentityColumn();
modelBuilder.Entity<Transaction>()
.Property(t => t.TransactionId)
.UseIdentityColumn();
modelBuilder.Entity<Transaction2Items>()
.Property(ti => ti.Transaction2ItemsId)
.UseIdentityColumn();
modelBuilder.Entity<TransactionNonItem>()
.Property(tni => tni.TransactionId)
.UseIdentityColumn();
modelBuilder.Entity<TaxSettings>()
.Property(ts => ts.TaxSettingsId)
.UseIdentityColumn();
modelBuilder.Entity<Discount>()
.Property(d => d.DiscountId)
.UseIdentityColumn();
modelBuilder.Entity<Transaction2Discount>()
.Property(t2d => t2d.Transaction2DiscountId)
.UseIdentityColumn();
modelBuilder.Entity<EmployeeRank2AspRole>()
.Property(e2a => e2a.EmployeeRank2AspRoleId)
.UseIdentityColumn();
/*
* Relations
*/
//Gender
modelBuilder.Entity<Gender2Employee>()
.HasOne<Employee>()
.WithMany()
.HasForeignKey(e => e.EmployeeId)
.HasPrincipalKey(e => e.EmployeeId);
modelBuilder.Entity<Gender2Employee>()
.HasOne<Gender>()
.WithMany()
.HasForeignKey(g => g.GenderId)
.HasPrincipalKey(g => g.GenderId);
//item
modelBuilder.Entity<ItemType2Item>()
.HasOne<Item>()
.WithMany()
.HasForeignKey(i => i.ItemId)
.HasPrincipalKey(i => i.ItemId);
modelBuilder.Entity<ItemType2Item>()
.HasOne<ItemType>()
.WithMany()
.HasForeignKey(i => i.ItemTypeId)
.HasPrincipalKey(i => i.ItemTypeId);
//transaction
//transaction2items
modelBuilder.Entity<Transaction2Items>()
.HasOne<Transaction>()
.WithMany()
.HasForeignKey(t => t.TransactionId)
.HasPrincipalKey(t => t.TransactionId);
modelBuilder.Entity<Transaction2Items>()
.HasOne<Item>()
.WithMany()
.HasForeignKey(i => i.ItemId)
.HasPrincipalKey(i => i.ItemId);
//transaction2discount
modelBuilder.Entity<Transaction2Discount>()
.HasOne<Transaction>()
.WithMany()
.HasForeignKey(t => t.TransactionId)
.HasPrincipalKey(t => t.TransactionId);
modelBuilder.Entity<Transaction2Discount>()
.HasOne<Discount>()
.WithMany()
.HasForeignKey(d => d.DiscountId)
.HasPrincipalKey(d => d.DiscountId);
//employeerank2asproleid
modelBuilder.Entity<EmployeeRank2AspRole>()
.HasOne<EmployeeRank>()
.WithMany()
.HasForeignKey(er => er.EmployeeRankId)
.HasPrincipalKey(er => er.EmployeeRankId);
}
}
}
In my Startup.cs I'm adding the context to the dependency injection like this:
//Database initialization
services.AddDbContext<PGSQLConnectionManager>(options =>
options.UseNpgsql(Configuration.GetConnectionString("PGSQLConnectionManager")));
services.AddDatabaseDeveloperPageExceptionFilter();
Now since my latest additional query I was using the Context like this:
In any .razor file I'm injecting the PGSQLConnectionManager:
#inject PGSQLConnectionManager Context
And later on in the .razor file in the #code part, I use the injected Context like this:
GetEmployee getAllEmployees = new GetEmployee(Context);
And every Class that needs a database connection is getting initialized like this:
public class GetEmployee
{
//Variables
private readonly PGSQLConnectionManager _connectionManager;
public GetEmployee(PGSQLConnectionManager context)
{
_connectionManager = context;
}
public List<Employee> GetAllEmployees()
{
try
{
//query all employees
List<Employee> allEmployees = _connectionManager.Employee.AsQueryable().ToList();
return allEmployees;
}
catch (Exception e)
{
#I know this is bad, but reporting is to come
return null;
}
}
}
And now, that I've done this like, >20 times I get an error: Connection is Busy
I tried using a static class and reference the PGSQLConnectionManager in there once, but then everytime I try to get the Context I get an error, that the Object has been disposed??? and can't get accessed anymore.
As far as I know, objects do not get disposed if they are in a static class.
I couldn't find where the database gets disposed in the static class thing.
So far, I think I'm using EntityFramework or the NPGSQL wrong. But I cannot find a good example, that represents my case.
Thanks ahead for any help
I'm new to C# / .NET Core and I'm trying to create a Web API. I have 2 models; Community & Rank
Community:
public class Community
{
public long Id { get; set; }
public long FrontId { get; set; }
public string Name { get; set; }
[ForeignKey("CommunityId")]
public virtual ICollection<Rank> Ranks { get; set; }
}
Rank:
public class Rank
{
public long Id { get; set; }
public long CommunityId { get; set; } [Required]
public string Name { get; set; } [Required]
public string Prefix { get; set; }
public virtual Community Community { get; set; }
}
I have my context set up like so:
public class CommunityContext : DbContext
{
public DbSet<Community> Communities { get; set; }
public DbSet<Rank> Ranks { get; set; }
public CommunityContext(DbContextOptions<CommunityContext> options) : base(options)
{
}
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
//Communities
builder.Entity<Community>(entity =>
{
entity.HasKey(c => c.Id);
entity.Property(c => c.Name).IsRequired();
entity.Property(c => c.FrontId).IsRequired();
// entity.Property(c => c.Ranks).IsRequired(false);
entity.HasMany(c => c.Ranks).WithOne().HasForeignKey(c => c.CommunityId).IsRequired();
});
//Ranks
builder.Entity<Rank>(entity =>
{
entity.HasKey(r => r.Id);
entity.Property(r => r.Name).IsRequired();
entity.Property(r => r.Prefix).IsRequired();
entity.Property(r => r.CommunityId).HasColumnName("CommunityId").IsRequired();
// entity.HasOne(r => r.Community).WithMany(s => s.Ranks);
});
}
}
I've done my database migrations etc, and when creating new entries, all works as expected currently, however trying to GET either communities or ranks returns the error:
MySql.Data.MySqlClient.MySqlException (0x80004005): Unknown column 'r.CommunityId1' in 'field list'
Any suggestions would be appreciated!
Thanks
Your Configurations should be like this:
...
//Communities
builder.Entity<Community>(entity =>
{
builder.ToTable("Community");
builder.HasKey(c => c.Id);
builder.Property(c => c.Id).HasColumnName("CommunityId").ValueGeneratedOnAdd();
entity.Property(c => c.Name).IsRequired();
entity.Property(c => c.FrontId).IsRequired();
// entity.Property(c => c.Ranks).IsRequired(false);
entity.HasMany(c => c.Ranks).WithOne().HasForeignKey(c => c.CommunityId).IsRequired();
});
//Ranks
builder.Entity<Rank>(entity =>
{
builder.ToTable("Rank");
builder.HasKey(r => r.Id);
builder.Property(r => r.Id).HasColumnName("RankId").ValueGeneratedOnAdd();
entity.Property(r => r.Name).IsRequired();
entity.Property(r => r.Prefix).IsRequired();
entity.Property(r => r.CommunityId).HasColumnName("CommunityId").IsRequired();
// entity.HasOne(r => r.Community).WithMany(s => s.Ranks);
});
...
I am following the guide on msdn : https://learn.microsoft.com/en-us/ef/core/modeling/relationships#other-relationship-patterns
Two classes between which i need many to many relatioship:
public class Initiative
{
public int InitiativeId { get; set; }
//other properties
}
public class AppUser : IdentityUser
{
//properties
}
My Join class :
public class UserVolunteer
{
public string userId;
public AppUser user;
public int initiativeId;
public Initiative initiative;
}
My fluent api code :
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<UserVolunteer>()
.HasKey(t => new { t.userId, t.initiativeId });
modelBuilder.Entity<UserVolunteer>()
.HasOne(bc => bc.user)
.WithMany(b => b.UserVolunteers)
.HasForeignKey(bc => bc.userId);
modelBuilder.Entity<UserVolunteer>()
.HasOne(bc => bc.initiative)
.WithMany(c => c.UserVolunteers)
.HasForeignKey(bc => bc.initiativeId);
}
while initializing migrations, i get the following error:
The properties expression 't => new <>f__AnonymousType0`2(userId = t.userId, initiativeId = t.initiativeId)' is not valid. The expression should represent a property access: 't => t.MyProperty'. When specifying multiple properties use an anonymous type: 't => new { t.MyProperty1, t.MyProperty2 }'.
Parameter name: propertyAccessExpression
I dont get whats the problem. I am doing the same as in guide and as in error.
In class UserVolunteer, userId and initiativeId is a public field and not a property. Therefore it throws exception on t => new { t.userId, t.initiativeId } because it is not a valid property access.
public class UserVolunteer
{
public string userId { get; set; }
public AppUser user { get; set; }
public int initiativeId { get; set; }
public Initiative initiative { get; set; }
}
I have introduced a many to many relationship between two of my existing tables. For this, I have added a third table, which contains only the Ids of the other two tables.
Since I am using EF, I have also added
public virtual List<EntityOne> EntityOnes in EntityTwo
and
public virtual List<EntityTwo> EntityTwos in EntityOne.
However, with this, when I get the EntityTwo object, it does not contain the associated EntityOne object. The list has a count of zero, even though the data is there in the tables.
Am I missing something here? Is there anything else, I need to do?
Not sure,if this is relevant, but I have also this in OnModelCreation
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<EntityOne>().
HasMany(p => p.EntityTwos).
WithMany(a => a.EntityOnes).
Map(
m =>
{
m.MapLeftKey("EntityTwoId");
m.MapRightKey("EntityOneId");
m.ToTable("EntityRelations");
});
////Make sure a context is not created by default.
}
Try this:
public partial class One
{
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public virtual int Id { get; set; }
private ICollection<OneTwo> _oneTwos;
public virtual ICollection<OneTwo> OneTwos
{
get { return _oneTwos ?? (_oneTwos = new List<OneTwo>()); }
set { _oneTwos = value; }
}
}
public partial class Two
{
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public virtual int Id { get; set; }
private ICollection<OneTwo> _oneTwos;
public virtual ICollection<OneTwo> OneTwos
{
get { return _oneTwos ?? (_oneTwos = new List<OneTwo>()); }
set { _oneTwos = value; }
}
}
Add navigation properties to the join class:
public partial class OneTwo
{
public virtual int OneId { get; set; }
public virtual int TwoId { get; set; }
public virtual One One { get; set; }
public virtual Two Two { get; set; }
}
Add composite key to the join class and configure relationships:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<OneTwo>() // composite primary key
.HasKey(p => new { p.OneId, p.TwoId });
modelBuilder.Entity<OneTwo>()
.HasRequired(a => a.One)
.WithMany(c => c.OneTwos)
.HasForeignKey(fk => fk.OneId)
.WillCascadeOnDelete(false);
modelBuilder.Entity<OneTwo>()
.HasRequired(a => a.Two)
.WithMany(c => c.OneTwos)
.HasForeignKey(fk => fk.TwoId)
.WillCascadeOnDelete(false);
// TODO: handle orphans when last asociation is deleted
}
An alternative strategy is to configure EF relationships via EntityTypeConfiguration<>. The following many-to-many relationship implementation demonstrates that approach:
City.cs
public partial class City
{
public virtual int Id { get; set; }
private ICollection<CountyCity> _countiesCities;
public virtual ICollection<CountyCity> CountiesCities
{
get { return _countiesCities ?? (_countiesCities = new List<CountyCity>()); }
set { _countiesCities = value; }
}
}
County.cs
public partial class County
{
public virtual int Id { get; set; }
private ICollection<CountyCity> _countiesCities;
public virtual ICollection<CountyCity> CountiesCities
{
get { return _countiesCities ?? (_countiesCities = new List<CountyCity>()); }
set { _countiesCities = value; }
}
}
CountyCity.cs
public partial class CountyCity
{
public virtual int CountyId { get; set; }
public virtual int CityId { get; set; }
public virtual County County { get; set; }
public virtual City City { get; set; }
}
CountyCityConfiguration.cs (EF 6 implementation)
public class CountyCityConfiguration : IEntityTypeConfiguration<CountyCity>
{
public void Map(EntityTypeBuilder<CountyCity> builder)
{
// Table and Schema Name declarations are optional
//ToTable("CountyCity", "dbo");
// composite primary key
builder.HasKey(p => new { p.CountyId, p.CityId });
builder.HasOne(pt => pt.County)
.WithMany(p => p.CountiesCities)
.HasForeignKey(pt => pt.CountyId)
.OnDelete(DeleteBehavior.Restrict);
builder.HasOne(pt => pt.City)
.WithMany(t => t.CountiesCities)
.HasForeignKey(pt => pt.CityId)
.OnDelete(DeleteBehavior.Restrict);
// TODO: handle orphans when last association is deleted
}
}
Entity Framework 6 Implementations:
You may configure the composite key and relationships using EntityTypeConfiguration<> as the previous code demonstrates.
Entity Framework Core Implementations:
EntityTypeConfiguration<> has not yet been migrated. However, it is on the roadmap for the next release.
In the meantime, you can employ the temporary pattern suggested by the EF team, or one of the patterns discussed this rather lengthy StackOverflow post discussing entity configuration in Entity Framework 7.
I implemented the pattern posted by Cocowalla in the lengthy discussion prior to reading the EF Team post. The source code for my workaround is available in this GitHub repository.
IEntityTypeConfiguration.cs
namespace Dna.NetCore.Core.DAL.EFCore.Configuration.Temporary.Cocowalla
{
// attribute: https://stackoverflow.com/questions/26957519/ef-7-mapping-entitytypeconfiguration/35373237#35373237
public interface IEntityTypeConfiguration<TEntityType> where TEntityType : class
{
void Map(EntityTypeBuilder<TEntityType> builder);
}
}
Here is my implementation of that pattern:
namespace Dna.NetCore.Core.DAL.EFCore.Configuration.Common
{
public class StateOrProvinceConfiguration : IEntityTypeConfiguration<StateOrProvince>
{
public void Map(EntityTypeBuilder<StateOrProvince> builder)
{
// EF Core
builder.HasOne(p => p.Country).WithMany(p => p.StateOrProvinces).HasForeignKey(s => s.CountryId).OnDelete(DeleteBehavior.Cascade);
builder.HasMany(d => d.Cities).WithOne().OnDelete(DeleteBehavior.Cascade);
builder.HasMany(d => d.Counties).WithOne().OnDelete(DeleteBehavior.Cascade);
}
}
}
I am trying to cache a select statement with no success.
I have this entity
public class Merchant : Entity<Merchant>
{
public virtual int Id { get; set; }
public virtual string Name { get; set; }
public virtual string Email { get; set; }
public virtual string OrdersEmail { get; set; }
public virtual string Host { get; set; }
}
The mapping is like this
public class MerchantMap : ClassMap<Merchant>
{
public MerchantMap()
{
Id(m => m.Id);
Map(m => m.Name);
Map(m => m.OrdersEmail);
Map(m => m.Email);
Map(m => m.Host);
Cache.ReadWrite();
ReadOnly();
}
}
.
The session factory is produced with this class:
public ISessionFactory TenantConfiguration()
{
var connectionString = System.Configuration
.ConfigurationManager
.ConnectionStrings["Tenant"]
.ConnectionString;
var config = Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2008
.ConnectionString(connectionString)
)
.Mappings(cfg => cfg.FluentMappings
.AddFromAssemblyOf<Entities.Merchant>()
)
.Cache(c =>
c.UseQueryCache()
.UseSecondLevelCache()
.ProviderClass<NHibernate.Cache.HashtableCacheProvider>()
.RegionPrefix("Tenant")
)
.ExposeConfiguration(c => c.SetProperty(
NHibernate.Cfg
.Environment
.SessionFactoryName,
"Tenant")
)
.BuildConfiguration();
var factory = config.BuildSessionFactory();
return factory;
}
public ISession CreateMerchantSession()
{
lock (factorySyncRoot)
{
return TenantConfiguration().OpenSession();
}
}
The only query i want to cache is the following one:
var merchants = new TenantSessionSource().CreateMerchantSession()
.QueryOver<Merchant>()
.Cacheable().Future().ToList();
I have tried almost everything and have red all the related questions but with no success. From the nhibernate profiler i see that everytime it opens a new session and executes this query repeatedly.
Any ideas?
Thanks