如何将OracleConfiguration参数融入EF Core Oracle数据库Scaffolding连接字符串？

我有一个.NET Core 6控制台应用，通过以下配置读取Oracle数据库数据，运行完全正常：

var connectionString = "User Id=MY_USER;Password=MY_PASSWORD;Data Source=MY_DATASOURCE;";    

OracleConfiguration.DirectoryServers = "(my.directory.server:123:456)";
OracleConfiguration.DirectoryServerType = "AD";
OracleConfiguration.DefaultAdminContext = "cn=my_cn,dc=my_dc_1,dc=my_dc_2";
OracleConfiguration.NamesDirectoryPath = "(LDAP)";
OracleConfiguration.SqlNetAuthenticationServices = "(NONE,NTS)";

_ = services.AddDbContext<DbContext, MyDbContext>(options =>
{
   _ = options.UseOracle(connectionString);
});

执行以下EF Core脚手架命令时，返回错误：ORA-12154: TNS:could not resolve the connect identifier specified

dotnet-ef dbcontext scaffold "User Id=MY_USER;Password=MY_PASSWORD;Data Source=MY_DATASOURCE;" "Oracle.EntityFrameworkCore" 

原因是dotnet-ef命令未加载代码中配置的OracleConfiguration参数，请问如何将这些自定义参数融入到脚手架命令的连接逻辑中？

方法1：将配置参数直接追加到连接字符串 #

Oracle支持将OracleConfiguration的参数作为键值对直接添加到连接字符串中，你可以把需要的参数拼接到脚手架命令的连接字符串里，示例如下：

dotnet-ef dbcontext scaffold "User Id=MY_USER;Password=MY_PASSWORD;Data Source=MY_DATASOURCE;Directory Servers=(my.directory.server:123:456);Directory Server Type=AD;Default Admin Context=cn=my_cn,dc=my_dc_1,dc=my_dc_2;Names Directory Path=(LDAP);Sql Net Authentication Services=(NONE,NTS);" "Oracle.EntityFrameworkCore"

注意参数名需保留空格，比如Directory Servers对应代码中的OracleConfiguration.DirectoryServers。

方法2：使用配置文件（推荐） #

1. 在项目根目录创建或修改appsettings.json，添加Oracle配置项：

{
  "ConnectionStrings": {
    "OracleDb": "User Id=MY_USER;Password=MY_PASSWORD;Data Source=MY_DATASOURCE;"
  },
  "Oracle": {
    "DirectoryServers": "(my.directory.server:123:456)",
    "DirectoryServerType": "AD",
    "DefaultAdminContext": "cn=my_cn,dc=my_dc_1,dc=my_dc_2",
    "NamesDirectoryPath": "(LDAP)",
    "SqlNetAuthenticationServices": "(NONE,NTS)"
  }
}

2. 创建设计时DbContext工厂类，用于脚手架命令读取配置：

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Design;
using Microsoft.Extensions.Configuration;
using Oracle.EntityFrameworkCore;
using Oracle.ManagedDataAccess.Client;
using System.IO;

public class MyDbContextFactory : IDesignTimeDbContextFactory<MyDbContext>
{
    public MyDbContext CreateDbContext(string[] args)
    {
        var configuration = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json")
            .Build();

        // 加载Oracle配置参数
        OracleConfiguration.DirectoryServers = configuration["Oracle:DirectoryServers"];
        OracleConfiguration.DirectoryServerType = configuration["Oracle:DirectoryServerType"];
        OracleConfiguration.DefaultAdminContext = configuration["Oracle:DefaultAdminContext"];
        OracleConfiguration.NamesDirectoryPath = configuration["Oracle:NamesDirectoryPath"];
        OracleConfiguration.SqlNetAuthenticationServices = configuration["Oracle:SqlNetAuthenticationServices"];

        var optionsBuilder = new DbContextOptionsBuilder<MyDbContext>();
        optionsBuilder.UseOracle(configuration.GetConnectionString("OracleDb"));

        return new MyDbContext(optionsBuilder.Options);
    }
}

3. 执行脚手架命令时，直接引用配置文件中的连接字符串即可：

dotnet-ef dbcontext scaffold "Name=ConnectionStrings:OracleDb" "Oracle.EntityFrameworkCore"

这种方法避免了命令行暴露敏感信息，配置也更易于维护。

方法3：使用环境变量 #

执行脚手架命令前，先设置对应Oracle环境变量（参数名需转换为大写并添加ORA_前缀）：

• Windows命令行：

set ORA_DIRECTORY_SERVERS=(my.directory.server:123:456)
set ORA_DIRECTORY_SERVER_TYPE=AD
set ORA_DEFAULT_ADMIN_CONTEXT=cn=my_cn,dc=my_dc_1,dc=my_dc_2
set ORA_NAMES_DIRECTORY_PATH=(LDAP)
set ORA_SQLNET_AUTHENTICATION_SERVICES=(NONE,NTS)

• Linux/macOS终端：

export ORA_DIRECTORY_SERVERS="(my.directory.server:123:456)"
export ORA_DIRECTORY_SERVER_TYPE="AD"
export ORA_DEFAULT_ADMIN_CONTEXT="cn=my_cn,dc=my_dc_1,dc=my_dc_2"
export ORA_NAMES_DIRECTORY_PATH="(LDAP)"
export ORA_SQLNET_AUTHENTICATION_SERVICES="(NONE,NTS)"

设置完成后，再执行原脚手架命令即可。

内容的提问来源于stack exchange，提问作者papps