使用Npgsql.EntityFrameworkCore.PostgreSQL逆向工程时遇System.IO.EndOfStreamException

问题场景 #

执行EF Core数据库逆向工程命令时抛出流读取异常：

dotnet ef dbcontext scaffold "<connection string>" Npgsql.EntityFrameworkCore.PostgreSQL -v

完整异常信息：

Npgsql.NpgsqlException (0x80004005): Exception while reading from stream
---> System.IO.EndOfStreamException: Attempted to read past the end of the stream.
at Npgsql.Internal.NpgsqlReadBuffer.g__EnsureLong|41_0(NpgsqlReadBuffer buffer, Int32 count, Boolean async, Boolean readingNotifications)
at Npgsql.Internal.NpgsqlReadBuffer.g__EnsureLong|41_0(NpgsqlReadBuffer buffer, Int32 count, Boolean async, Boolean readingNotifications)
at Npgsql.Internal.NpgsqlConnector.RawOpen(SslMode sslMode, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken, Boolean isFirstAttempt)
at Npgsql.Internal.NpgsqlConnector.g__OpenCore|191_1(NpgsqlConnector conn, SslMode sslMode, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken, Boolean isFirstAttempt)
at Npgsql.Internal.NpgsqlConnector.Open(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.ConnectorPool.OpenNewConnector(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.ConnectorPool.g__RentAsync|28_0(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnection.g__OpenAsync|45_0(Boolean async, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnection.Open()
at Npgsql.EntityFrameworkCore.PostgreSQL.Scaffolding.Internal.NpgsqlDatabaseModelFactory.Create(DbConnection dbConnection, DatabaseModelFactoryOptions options)
at Npgsql.EntityFrameworkCore.PostgreSQL.Scaffolding.Internal.NpgsqlDatabaseModelFactory.Create(String connectionString, DatabaseModelFactoryOptions options)
at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineerScaffolder.ScaffoldModel(String connectionString, DatabaseModelFactoryOptions databaseOptions, ModelReverseEngineerOptions modelOptions, ModelCodeGenerationOptions codeOptions)
at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext(String provider, String connectionString, String outputDir, String outputContextDir, String dbContextClassName, IEnumerable1 schemas, IEnumerable1 tables, String modelNamespace, String contextNamespace, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames, Boolean suppressOnConfiguring, Boolean noPluralize)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl(String provider, String connectionString, String outputDir, String outputDbContextDir, String dbContextClassName, IEnumerable1 schemaFilters, IEnumerable1 tableFilters, String modelNamespace, String contextNamespace, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames, Boolean suppressOnConfiguring, Boolean noPluarlize)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContext.<>c__DisplayClass0_0.<.ctor>b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)

使用包版本：Npgsql.EntityFrameworkCore.PostgreSQL 6.0.7

可行解决方案 #

1. 调整连接字符串的SSL配置 #

该异常多与SSL连接冲突相关，尝试修改连接字符串中的SslMode参数：

• 若数据库无需SSL，显式关闭：

  SslMode=Disable
  

• 若需要SSL但证书验证异常，添加信任配置：

  SslMode=Require;Trust Server Certificate=true
  

2. 升级Npgsql包到兼容补丁版 #

6.0.7版本存在已知连接稳定性问题，建议升级到同主版本的最新补丁（如6.0.22，.NET 6 LTS适配版）：

dotnet add package Npgsql.EntityFrameworkCore.PostgreSQL --version 6.0.22

3. 验证数据库服务器连通性 #

• 确认PostgreSQL服务正常运行，默认端口5432未被防火墙/安全组拦截
• 使用psql工具直接测试连接，排除网络问题：

  psql "host=<你的服务器地址> port=5432 dbname=<数据库名> user=<用户名> password=<密码>"
  

4. 增加连接超时参数 #

在连接字符串中添加超时配置，避免网络延迟导致连接中断：

Timeout=30;CommandTimeout=30

5. 检查数据库连接数上限 #

若服务器连接数已满，会导致新连接被异常终止，登录数据库执行以下命令排查：

SHOW max_connections;
SELECT count(*) FROM pg_stat_activity;

若连接数接近上限，需调整服务器配置或关闭闲置连接。

内容的提问来源于stack exchange，提问作者Vinyl Warmth