这可能是 Windows 7 的问题，但调用
using (var context = new DataClassesDataContext())
{
if (!context.DatabaseExists())
{
context.CreateDatabase();
}
}
导致以下错误:
System.Data.SqlClient.SqlException was unhandled Message=Database 'C:\Temp\SmallBusinessManager.mdf' already exists. Choose a different database name. Source=.Net SqlClient Data Provider ErrorCode=-2146232060 Class=16 LineNumber=1 Number=1801 Procedure=""
Server=\.\pipe\952FCA9D-B4B6-4C\tsql\query State=3 StackTrace: at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning() at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at System.Data.Linq.SqlClient.SqlProvider.ExecuteCommand(String command) at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.CreateDatabase() at System.Data.Linq.DataContext.CreateDatabase()
但是我已经删除了数据库文件。是什么原因造成的？这些文件真的存在但不知何故不可见吗？与路口有关吗？
最佳答案
跟踪错误
所以我也一直在尝试通过运行 DataContext.CreateDatabase() 命令并得到相同的错误。
我使用的是带有 SQLExpress 2008 和 VS2008 的 Vista SP2，并将 Process Monitor 用作 Josh建议 his answer这里。这让我看到 SQL Server 正在写入其 error.log 文件，该文件又揭示了以下相关信息 block (此处提供了完整信息，以防其他人在消息中看到有用的信息):
2010-06-23 17:04:10.50 Server SQL Server is starting at normal priority base (=7). This is an informational message only. No user action is required.
2010-06-23 17:04:10.50 Server Detected 2 CPUs. This is an informational message; no user action is required.
2010-06-23 17:04:10.55 Server Perfmon counters for resource governor pools and groups failed to initialize and are disabled.
2010-06-23 17:04:10.55 Server Using dynamic lock allocation. Initial allocation of 2500 Lock blocks and 5000 Lock Owner blocks per node. This is an informational message only. No user action is required.
2010-06-23 17:04:10.65 Server Node configuration: node 0: CPU mask: 0x00000003 Active CPU mask: 0x00000003. This message provides a description of the NUMA configuration for this computer. This is an informational message only. No user action is required.
2010-06-23 17:04:10.69 spid7s Starting up database 'master'.
2010-06-23 17:04:10.79 spid7s 1 transactions rolled forward in database 'master' (1). This is an informational message only. No user action is required.
2010-06-23 17:04:10.91 spid7s 0 transactions rolled back in database 'master' (1). This is an informational message only. No user action is required.
2010-06-23 17:04:10.91 spid7s Recovery is writing a checkpoint in database 'master' (1). This is an informational message only. No user action is required.
2010-06-23 17:04:11.12 spid7s Error: 5598, Severity: 16, State: 2.
2010-06-23 17:04:11.12 spid7s FILESTREAM feature is not supported on user instances.
2010-06-23 17:04:11.12 spid7s FILESTREAM: effective level = 0, configured level = 0, file system access share name = 'SQLEXPRESS'.
2010-06-23 17:04:11.25 spid7s SQL Trace ID 1 was started by login "sa".
2010-06-23 17:04:11.31 spid7s Starting up database 'mssqlsystemresource'.
2010-06-23 17:04:11.33 spid7s The resource database build version is 10.00.2531. This is an informational message only. No user action is required.
2010-06-23 17:04:11.90 spid9s Starting up database 'model'.
2010-06-23 17:04:11.91 Server Server local connection provider is ready to accept connection on [ \\.\pipe\95B6C915-3DB7-46\tsql\query ].
2010-06-23 17:04:11.94 Server Dedicated administrator connection support was not started because it is disabled on this edition of SQL Server. If you want to use a dedicated administrator connection, restart SQL Server using the trace flag 7806. This is an informational message only. No user action is required.
2010-06-23 17:04:11.95 spid7s Server name is 'JOHN-W500\95B6C915-3DB7-46'. This is an informational message only. No user action is required.
2010-06-23 17:04:12.22 spid7s Starting up database 'msdb'.
2010-06-23 17:04:12.27 Server The SQL Server Network Interface library could not register the Service Principal Name (SPN) for the SQL Server service. Error: 0x5, state: 4. Failure to register an SPN may cause integrated authentication to fall back to NTLM instead of Kerberos. This is an informational message. Further action is only required if Kerberos authentication is required by authentication policies.
2010-06-23 17:04:12.27 Server SQL Server is now ready for client connections. This is an informational message; no user action is required.
2010-06-23 17:04:12.60 spid9s Clearing tempdb database.
2010-06-23 17:04:15.49 spid9s Starting up database 'tempdb'.
2010-06-23 17:04:16.27 spid12s The Service Broker protocol transport is disabled or not configured.
2010-06-23 17:04:16.27 spid12s The Database Mirroring protocol transport is disabled or not configured.
2010-06-23 17:04:16.36 spid12s Service Broker manager has started.
2010-06-23 17:04:16.37 spid7s Recovery is complete. This is an informational message only. No user action is required.
2010-06-23 17:04:17.84 Logon Error: 15350, Severity: 16, State: 1.
2010-06-23 17:04:17.84 Logon An attempt to attach an auto-named database for file C:\y\bjdatamig\IntermediateData.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
2010-06-23 17:31:29.89 Logon Error: 15350, Severity: 16, State: 1.
2010-06-23 17:31:29.89 Logon An attempt to attach an auto-named database for file C:\y\bjdatamig\IntermediateData.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
2010-06-23 17:33:07.09 Logon Error: 15350, Severity: 16, State: 1.
2010-06-23 17:33:07.09 Logon An attempt to attach an auto-named database for file C:\y\bjdatamig\IntermediateData.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
2010-06-23 17:49:53.53 Logon Error: 15350, Severity: 16, State: 1.
2010-06-23 17:49:53.53 Logon An attempt to attach an auto-named database for file C:\y\bjdatamig\IntermediateData.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
2010-06-23 18:01:02.74 Logon Error: 15350, Severity: 16, State: 1.
2010-06-23 18:01:02.74 Logon An attempt to attach an auto-named database for file C:\y\bjdatamig\IntermediateData.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
2010-06-23 18:02:50.92 Logon Error: 15350, Severity: 16, State: 1.
2010-06-23 18:02:50.92 Logon An attempt to attach an auto-named database for file C:\y\bjdatamig\IntermediateData.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
2010-06-23 18:04:06.31 Logon Error: 15350, Severity: 16, State: 1.
2010-06-23 18:04:06.31 Logon An attempt to attach an auto-named database for file C:\y\bjdatamig\IntermediateData.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
2010-06-23 18:06:41.22 Logon Error: 15350, Severity: 16, State: 1.
2010-06-23 18:06:41.22 Logon An attempt to attach an auto-named database for file C:\y\bjdatamig\IntermediateData.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
我的 SQL 日志文件位于:
C:\Users\John\AppData\Local\Microsoft\Microsoft SQL Server Data\SQLEXPRESS\error.log
重要的是，对于我的情况，它表明用户实例不支持“功能”，似乎是关于流式传输文件，当然 CreateDatabase 正在尝试写入文件系统 ...
2010-06-23 17:04:11.12 spid7s Error: 5598, Severity: 16, State: 2.
2010-06-23 17:04:11.12 spid7s FILESTREAM feature is not supported on user instances.
...我在 APP.CONFIG 中的连接字符串也指定了“用户实例”...
<add connectionString="Data Source=JOHN-W500\SQLEXPRESS;AttachDbFilename=C:\y\bjdatamig\IntermediateData.mdf;Integrated Security=True;User Instance=True" name="IntermediateData" providerName="System.Data.SqlClient" />
解决方案
我更改了我的连接字符串
;Integrated Security=True;
到
;Integrated Security=False;
数据库是在文件系统上创建的。
为什么我不必更改“用户实例”选项？好吧，我不确定。事实上，在我开始出现这个错误之前，代码可以正常工作，但我已经一个月没有尝试过 - 我的猜测可能是系统更新或对 SQL Server 的更改导致了它。所以虽然固定了，但还是有点神秘。
关于c# - DataContext.CreateDatabase() 说文件已经存在 - 但它不存在，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/2796013/