Quick question for you database experts. See the following code (VBA/ADO), called from Excel:
快速提问数据库专家。请参阅从Excel调用的以下代码（VBA / ADO）：
Dim DBPath As String, ConnStr As String
DBPath = ThisWorkbook.Path & Application.PathSeparator & "Database.mdb"
ConnStr = "Data Source=" & DBPath & ";" & "Jet OLEDB:Database Password=" & DBPass()
Dim cnn as ADODB.Connection
Set cnn = New ADODB.Connection
With cnn
.Provider = CheckProvider(strPath:=DBPath) ' Separate function call. Ignore
.Mode = adModeRead
.Open ConnStr
End With
Stop ' To inspect the directory...
It should open the database as read-only, given the "adModeRead" specification. However I have noticed that a lock file (Database.ldb) is still being created/deleted in the directory while the connection is active. Surely this goes contrary to the read-only command, which should mean that no data may be written, and therefore no file lock is needed.
在给定“adModeRead”规范的情况下，它应该以只读方式打开数据库。但是我注意到，当连接处于活动状态时，仍在目录中创建/删除锁定文件（Database.ldb）。当然这与只读命令相反，这意味着不能写入任何数据，因此不需要文件锁定。
Can anyone explain what's happening here? Thanks.
谁能解释这里发生了什么？谢谢。
Edit: And a follow-up - if I wanted to open the connection as purely read-only without creating any lock file, is there any other method?
编辑：和后续 - 如果我想打开连接纯粹只读而不创建任何锁定文件，还有其他方法吗？
1 个解决方案
#1
3
The lock file records connections to the db file. That information is important in a multi-user context. Even if yours is the only connection and is intentionally read-only, Access still records that connection in the lock file. It would be important in a situation where another used wanted to connect to the same db file in exclusive mode in order to make design changes --- they would not be allowed exclusive access while your connection is still active.
锁定文件记录与db文件的连接。该信息在多用户环境中很重要。即使您的连接是唯一的连接并且是有意读取的，Access仍会在锁定文件中记录该连接。在另一个使用过的人希望以独占模式连接到同一个db文件以进行设计更改的情况下，这将非常重要 - 在您的连接仍处于活动状态时，不允许独占访问。
#1
3
The lock file records connections to the db file. That information is important in a multi-user context. Even if yours is the only connection and is intentionally read-only, Access still records that connection in the lock file. It would be important in a situation where another used wanted to connect to the same db file in exclusive mode in order to make design changes --- they would not be allowed exclusive access while your connection is still active.
锁定文件记录与db文件的连接。该信息在多用户环境中很重要。即使您的连接是唯一的连接并且是有意读取的，Access仍会在锁定文件中记录该连接。在另一个使用过的人希望以独占模式连接到同一个db文件以进行设计更改的情况下，这将非常重要 - 在您的连接仍处于活动状态时，不允许独占访问。