Data Source Name
The Data Source Name ( DSN) is a data structure (similar to a URL or file path), which in database abstraction frameworks ( database abstraction layer) such as ODBC (Open Database Connectivity), JDBC or ADOdb the access describes that requires a driver to connect to a establish specific database based on a specific RDBMSs.
The DSN contains information such as the name, the directory and the driver of the database and, based on the type of DSN, the ID and password of the user.
Depending on the framework, the notation of the DSN so distinct in part:
Various notations
JDBC
Mysql :/ / root: rootpw @ localhost / MyDatabase ODBC
For ODBC DSNs exist different forms of representation. Either the DSN ' hard-wired ' and incorporated as a DSN -less connection directly in the program code. Then, the display is as follows:
DBQ = C: \ TEST \ QUERY FILES; DefaultDir = C: \ TEST \ QUERY FILES; _ Deleted = 1; Driver = { Microsoft dBase Driver (* dbf. ) }; _ DriverId = 277; FIL = dBase IV; Page Timeout = 600; Statistics = 0 In addition, there is the possibility to save the DSN in the registry ( in older versions of MS- Query) or in so-called file DSNs. This term is chosen to be somewhat unhappy by Microsoft, as it is not a DSN reference ON is a file (eg XML file) but a DSN reference IN a file.
Accordingly, a file DSN or a DSN file containing data in a notation similar to an ini file. :
[ ODBC]
DRIVER = Microsoft Excel Driver (*. Xls)
UID = admin
UserCommitSync = Yes
Threads = 3
Safe Transactions = 0
ReadOnly = 1
Page Timeout = 5
MaxScanRows = 8
MaxBufferSize = 512
ImplicitCommitSync = Yes
FIL = excel 5.0
DriverId = 790
DefaultDir =
- User DSN (User DSN)
- System DSN ( DSN Machine )
- File (DSN File DSN)
User and system DSNs are specific computer and save the DSN information in the registry. A User DSN allows database access for a single user on a single computer, a System DSN for each user of a particular computer. A File DSN contains relevant information in a text file with a. DSN file extension and can be used by multiple users and multiple computers if they have installed the same database drivers.