How to use multiples databases in ABP Core Zero?
Connect with multiple database in ASP.NET ZERO/ASP.NET BOILERPLATE.
Note - Use seperate DB Context to use multiple Databases.
Step 1. Create modal class in "MultipleDbContextEfCoreDemo.Core" Project for your tables.
[Table ("tblStudent")] //Is in First Database
public class Student : Entity<long> {
public int ID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
protected Student () { }
}
[Table ("tblCourses")] //Is in Second Database
public class Courses : Entity<long> {
public int ID { get; set; }
public string CourseName { get; set; }
public string Standard { get; set; }
protected Courses () { }
}
Step 2. In same project("MultipleDbContextEfCoreDemo.Core" Project) create/use "MultipleDbContextEfCoreDemoConsts.cs" file to add Database Connection names.
public class MultipleDbContextEfCoreDemoConsts
{
public const string LocalizationSourceName = "MultipleDbContextEfCoreDemo";
public const string ConnectionStringName = "Default";
public const string SecondDbConnectionStringName = "Second";
}
Step 3. In "MultipleDbContextEfCoreDemo.EntityFrameworkCore" Project goto "EntityFrameworkCore" Folder and create individual "DBContext" and "DbContextConfigurer" file for each database connection to which you want to connect.
FirstDatabase Setting -
required files to connect to first db -
1. FirstDbContext.cs
public class FirstDbContext : AbpDbContext, IAbpPersistedGrantDbContext {
/* Define an IDbSet for each entity of the application */
public DbSet<PersistedGrantEntity> PersistedGrants { get; set; }
public virtual DbSet<Student> Student { get; set; }
public FirstDbContext (DbContextOptions<FirstDbContext> options) : base (options) {
}
protected override void OnModelCreating (ModelBuilder modelBuilder) { }
}
2. FirstDbContextConfigurer
public static class FirstDbContextConfigurer {
public static void Configure (DbContextOptionsBuilder<FirstDbContext> builder, string connectionString) {
builder.UseSqlServer (connectionString);
}
public static void Configure (DbContextOptionsBuilder<FirstDbContext> builder, DbConnection connection) {
builder.UseSqlServer (connection);
}
}
SecondDatabase Setting -
required files to connect to second db -
1. SecondDbContext.cs
public class SecondDbContext : AbpDbContext, IAbpPersistedGrantDbContext {
/* Define an IDbSet for each entity of the application */
public DbSet<PersistedGrantEntity> PersistedGrants { get; set; }
public virtual DbSet<Student> Student { get; set; }
public SecondDbContext (DbContextOptions<SecondDbContext> options) : base (options) {
}
protected override void OnModelCreating (ModelBuilder modelBuilder) { }
}
2. SecondDbContextConfigurer
public static class SecondDbContextConfigurer {
public static void Configure (DbContextOptionsBuilder<SecondDbContext> builder, string connectionString) {
builder.UseSqlServer (connectionString);
}
public static void Configure (DbContextOptionsBuilder<SecondDbContext> builder, DbConnection connection) {
builder.UseSqlServer (connection);
}
}
Step 4. Then in same project("MultipleDbContextEfCoreDemo.EntityFrameworkCore") add "MyConnectionStringResolver.cs"
public class MyConnectionStringResolver : DefaultConnectionStringResolver
{
public MyConnectionStringResolver(IAbpStartupConfiguration configuration)
: base(configuration)
{
}
public override string GetNameOrConnectionString(ConnectionStringResolveArgs args)
{
if (args["DbContextConcreteType"] as Type == typeof(SecondDbContext))
{
var configuration = AppConfigurations.Get(WebContentDirectoryFinder.CalculateContentRootFolder());
return configuration.GetConnectionString(MultipleDbContextEfCoreDemoConsts.SecondDbConnectionStringName);
}
return base.GetNameOrConnectionString(args);
}
}
Step 5. Then in same project("MultipleDbContextEfCoreDemo.EntityFrameworkCore"), Update "MultipleDbContextEfCoreDemoEntityFrameworkCoreModule.cs" file to replace the "IConnectionStringResolver" with our custom implementation MyConnectionStringResolver.
[DependsOn(typeof(MultipleDbContextEfCoreDemoCoreModule), typeof(AbpEntityFrameworkCoreModule))]
public class MultipleDbContextEfCoreDemoEntityFrameworkCoreModule : AbpModule
{
public override void PreInitialize()
{
Configuration.ReplaceService<IConnectionStringResolver, MyConnectionStringResolver>();
// Configure first DbContext
Configuration.Modules.AbpEfCore().AddDbContext<FirstDbContext>(options =>
{
if (options.ExistingConnection != null)
{
FirstDbContextConfigurer.Configure(options.DbContextOptions, options.ExistingConnection);
}
else
{
FirstDbContextConfigurer.Configure(options.DbContextOptions, options.ConnectionString);
}
});
// Configure second DbContext
Configuration.Modules.AbpEfCore().AddDbContext<SecondDbContext>(options =>
{
if (options.ExistingConnection != null)
{
SecondDbContextConfigurer.Configure(options.DbContextOptions, options.ExistingConnection);
}
else
{
SecondDbContextConfigurer.Configure(options.DbContextOptions, options.ConnectionString);
}
});
}
public override void Initialize()
{
IocManager.RegisterAssemblyByConvention(typeof(MultipleDbContextEfCoreDemoEntityFrameworkCoreModule).GetAssembly());
}
}
Step 6. Create the Service in "MultipleDbContextEfCoreDemo.Application" project with Dto, Interface and Service Class.
ITestAppService.cs-
public interface ITestAppService : IApplicationService
{
List<string> GetStudentAndCourses();
}
TestAppService.cs
public class TestAppService : MultipleDbContextEfCoreDemoAppServiceBase, ITestAppService
{
private readonly IRepository<Student> _studentRepository; //in the first db
private readonly IRepository<Courses> _coursesRepository; //in the second db
public TestAppService(
IRepository<Student> studentRepository,
IRepository<Courses> coursesRepository
)
{
_studentRepository = studentRepository;
_coursesRepository = coursesRepository;
}
//a sample method uses both databases concurrently
public List<string> GetStudentAndCourses()
{
List<string> names = new List<string>();
var studentNames = _studentRepository.GetAllList().Select(p => "Student: " + p.FirstName).ToList();
names.AddRange(peopleNames);
var courseNames = _coursesRepository.GetAllList().Select(p => "Course: " + p.CourseName).ToList();
names.AddRange(courseNames);
return names;
}
}
Step 7. Add Database connectionStrings to your MultipleDbContextEfCoreDemo.Web/MultipleDbContextEfCoreDemo.Web.Host project's "appsettings.json" file.
{
"ConnectionStrings": {
"Default":
"Server=XXX.XXX.XX.XX;Database=firstDB;Integrated Security=False;TrustServerCertificate=True;User ID=XX;Password=XXX;",
"Second":
"Server=XXX.XXX.XX.XX;Database=secondDB;Integrated Security=False;TrustServerCertificate=True;User ID=XX;Password=XXX;"
}
}
Step 8. Use Service in your angular/MVC project.
I ran into the same problem as @Sniipe with regards to navigational properties.
The problem was that I was inheriting from
AbpZeroDbContext<Tenant, Role, User, PortalDbContext>
in my second DBContext instead of just
AbpDbContext