Question

我们正致力于将来自不同源系统（Firebird，Oracle，SQL Server）的数据迁移到一个目标系统（SQL Server）。

我们从Firebird连接中读取连接异常中的数据时出现错误。

我们正在使用的代码


用于创建SourceSystem对象的静态DbFactory类

public static class DbFactory { public static DbManager CreateDb(SourceDbType type) { switch (type) { case SourceDbType.Sql: return new SqlDbManager(); case SourceDbType.FireBird: return new FireBirdDbManager(); } return null; } } public enum SourceDbType { Sql, FireBird }


Base DbManager Class

public abstract class DbManager { private DbConnection m_DbConnection; public virtual DbConnection DbConnection { get { if (m_DbConnection == null) { m_DbConnection = new SqlConnection(); } return m_DbConnection; } set { this.m_DbConnection = value; } } public virtual void SetConnectionString(Migration migration, DataTable dtConnectionDetails = null) { try { DbConnection.ConnectionString = string.Format("Server={0};Database={1};User ID={2};Password={3};", migration.NetworkPartnerData.Server, migration.NetworkPartnerData.Database, migration.NetworkPartnerData.User, AESEncryptionDecryptionUtility.DecodeBase64(migration.NetworkPartnerData.Password)); } catch { throw; } } public virtual void SetConnectionString(string connectionString) { try { DbConnection.ConnectionString = connectionString; } catch { throw; } } public virtual DataTable ExecuteDataTable(string ConnectionString, string queryText) { throw new NotImplementedException(); } }


从DbManager继承的FireBirdDbManager类

public class FireBirdDbManager : DbManager { private FbConnection fbconnection; public override DbConnection DbConnection { get { if (fbconnection == null) { fbconnection = new FbConnection(); } return fbconnection; } set { this.fbconnection = value as FbConnection; } } public override void SetConnectionString(Migration migration, DataTable connectionDetails) { this.DbConnection.ConnectionString = string.Format("Server={0};Database={1};Port=3050;User ID={2};Password={3};Pooling=true;MinPoolSize=0;MaxPoolSize=50;", migration.NetworkPartnerData.Server, migration.NetworkPartnerData.Database + BuildDatabaseName(Convert.ToString(connectionDetails.Rows[0]["CL_NBR"])) + ApplicationConstants.FIREBIRD_DBFILE_EXTENSION, migration.NetworkPartnerData.User, iMigrationTool.Common.AESEncryptionDecryptionUtility.DecodeBase64(migration.NetworkPartnerData.Password)); } public override DataTable ExecuteDataTable(string ConnectionString, string queryText) { using (var connection = new FbConnection(ConnectionString)) { try { DataTable dt = new DataTable(); connection.Open(); using (FbTransaction readTransaction = connection.BeginTransaction(IsolationLevel.ReadCommitted)) { FbCommand readCommand = new FbCommand(); try { readCommand.CommandText = queryText; readCommand.Connection = connection; readCommand.Transaction = readTransaction; FbDataAdapter da = new FbDataAdapter(readCommand); da.SelectCommand.CommandType = CommandType.Text; da.Fill(dt); readTransaction.Commit(); } catch { readTransaction.Rollback(); throw; } finally { readTransaction.Dispose(); if (connection.State == ConnectionState.Open) { connection.Close(); } connection.Dispose(); } return dt; } } catch (Exception ex) { int errorCode = ex.HResult; Logger.LogApplicationException(ex, null, "ERRORCODE:" + errorCode + "ConnectionString:" + ConnectionString, "MigrationWorker"); throw ex; } } } }

异常图片

我们在运行3到4次迁移后遇到异常。如果我再次重新启动服务，我们可以运行3到4次迁移。

我们用来调用相应源系统的代码：

我们对Firebird数据库系统很新，无法解决问题。另外，我们正在使用Visual Studio 2012，Azure云服务

Answer 1

我们能够在通过ADO.NET数据提供程序（版本4.7.0）执行查询期间通过任务管理器终止Firebird任务来重现Firebird 2.1.3.18185的问题。之后，我们总是收到以下异常：

System.Data.Entity.Core.EntityCommandExecutionException: An error occurred 
while executing the command definition. See the inner exception for details. 
    ---> FirebirdSql.Data.FirebirdClient.FbException: Error reading data from 
    the connection.
    ---> FirebirdSql.Data.Common.IscException: Error reading 
    data from the connection. at 
    FirebirdSql.Data.Client.Managed.Version10.GdsTransaction.BeginTransaction(Transa
    ctionParameterBuffer tpb) in c: Users Jiri Documents devel NETProvider 
    working NETProvider src FirebirdSql.Data.FirebirdClient Client Managed 
    Version10 GdsTransaction.cs:line 162 at 
    FirebirdSql.Data.Client.Managed.Version10.GdsDatabase.BeginTransaction(Transacti
    onParameterBuffer tpb) in c: Users Jiri Documents devel NETProvider working 
    NETProvider src FirebirdSql.Data.FirebirdClient Client Managed Version10 
    GdsDatabase.cs:line 571 at 
    FirebirdSql.Data.FirebirdClient.FbTransaction.BeginTransaction() in c: Users 
    Jiri Documents devel NETProvider working NETProvider src 
    FirebirdSql.Data.FirebirdClient FirebirdClient FbTransaction.cs:line 363 
— End of inner exception stack trace —

在我们的案例中，通过禁用连接池（connection-string：'...; Pooling = false'）解决并验证了问题。对我们感兴趣的是，根据[1]，这是使用连接池时预期的行为，其中连接已在多个请求之间断开连接。

我希望这个答案可以帮助别人。在我们的案例中，此解决方案也适用于当前的ADO.NET 5.0.5。

祝你好运，托马斯

[1] http://tracker.firebirdsql.org/browse/DNET-585?page=com.atlassian.jira.plugin.system.issuetabpanels%3Aall-tabpanel

Answer 2

当执行查询长度> 最大查询长度

时，出现此错误在FireBird 4.x中，

我从连接读取数据时出错更新到6.6后，我收到新错误“ 335544721 ：无法完成对主机的网络请求...”

它已通过拆分查询固定为较少的查询

（使用UTF-8时默认为8191个字符）

从连接Firebird读取数据时出错

2 个答案: