What is the right way to work with multiple providers? My Example:
appsettings.json
{
"ConnectionStrings": {
"Sqlite": "Data Source=database.db"
}
}
Startup.cs
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<DatabaseContext>(options =>
options.UseSqlite(Configuration.GetConnectionString("Sqlite")));
}
DatabaseContext.cs
public class DatabaseContext : DbContext
{
public DatabaseContext(DbContextOptions<DatabaseContext> options) : base(options) { }
public DbSet<TestModel> TestModel{ get; set; }
}
A easy way for multiple providers?
A solution with only one Context (Example for SQLite + MySQL + MSSQL + PostgreSQL (or others)):
appsettings.json
{
// Add Provider and ConnectionStrings for your EFC drivers
// Providers: SQLite, MySQL, MSSQL, PostgreSQL, or other provider...
"Provider": "SQLite",
"ConnectionStrings": {
"SQLite": "Data Source=mydatabase.db",
"MySQL": "server=localhost;port=3306;database=mydatabase;user=root;password=root",
"MSSQL": "Server=(localdb)\\mssqllocaldb;Database=mydatabase;Trusted_Connection=True;MultipleActiveResultSets=true",
"PostgreSQL": "Host=localhost;Database=mydatabase;Username=root;Password=root"
}
}
Single DatabaseContext.cs
public class DatabaseContext : DbContext
{
public DatabaseContext(DbContextOptions<DatabaseContext> options) : base(options) { }
// add Models...
}
Startup.cs
public void ConfigureServices(IServiceCollection services)
{
// Check Provider and get ConnectionString
if (Configuration["Provider"] == "SQLite")
{
services.AddDbContext<DatabaseContext>(options =>
options.UseSqlite(Configuration.GetConnectionString("SQLite")));
}
else if (Configuration["Provider"] == "MySQL")
{
services.AddDbContext<DatabaseContext>(options =>
options.UseMySql(Configuration.GetConnectionString("MySQL")));
}
else if (Configuration["Provider"] == "MSSQL")
{
services.AddDbContext<DatabaseContext>(options =>
options.UseSqlServer(Configuration.GetConnectionString("MSSQL")));
}
else if (Configuration["Provider"] == "PostgreSQL")
{
services.AddDbContext<DatabaseContext>(options =>
options.UseNpgsql(Configuration.GetConnectionString("PostgreSQL")));
}
// Exception
else
{ throw new ArgumentException("Not a valid database type"); }
}
Now we can do a singel migration
Add-Migration InitialCreate
Only edit every output of Add-Migration and add driver specific attributes:
protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.CreateTable(
name: "Mytable",
columns: table => new
{
Id = table.Column<int>(nullable: false)
// Add for SQLite
.Annotation("Sqlite:Autoincrement", true)
// Add for MySQL
.Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn)
// Add for MSSQL
.Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn)
// Add for PostgreSQL
.Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.SerialColumn),
// Or other provider...
Name = table.Column<string>(maxLength: 50, nullable: false),
Text = table.Column<string>(maxLength: 100, nullable: true)
},
constraints: table =>
{
table.PrimaryKey("PK_Mytable", x => x.Id);
});
}
EDIT: or you use string ID "DatabaseGenerated" so you would not have to edit migrationBuilder and the add migration is multiple providers capable without ".Annotation"
EXAMPLE Model:
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
namespace WebApplication.Models
{
public class Mytable
{
// This generate a String ID
// No ID modification needed for providers
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public string Id { get; set; }
// ....
}
}
Now ready for Update-Database
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