ConnectionString Property (ADO)
Indicates the information used to establish a connection to a data source.
Settings and Return Values
Sets or returns a String value.
Remarks
Use the ConnectionString property to specify a data source by passing a detailed connection string containing a series of argument = value statements separated by semicolons.
ADO supports five arguments for the ConnectionString property; any other arguments pass directly to the provider without any processing by ADO. The arguments ADO supports are as follows.
| Argument | Description |
|---|---|
| Provider= | Specifies the name of a provider to use for the connection. |
| File Name= | Specifies the name of a provider-specific file (for example, a persisted data source object) containing preset connection information. |
| Remote Provider= | Specifies the name of a provider to use when opening a client-side connection. (Remote Data Service only.) |
| Remote Server= | Specifies the path name of the server to use when opening a client-side connection. (Remote Data Service only.) |
| URL= | Specifies the connection string as an absolute URL identifying a resource, such as a file or directory. |
After you set the ConnectionString property and open the Connection object, the provider may alter the contents of the property, for example, by mapping the ADO-defined argument names to their equivalents for the specific provider.
The ConnectionString property automatically inherits the value used for the ConnectionString argument of the Open method, so you can override the current ConnectionString property during the Open method call.
Because the File Name argument causes ADO to load the associated provider, you cannot pass both the Provider and File Name arguments.
The ConnectionString property is read/write when the connection is closed and read-only when it is open.
Duplicates of an argument in the ConnectionString property are ignored. The last instance of any argument is used.
Note
Remote Data Service Usage When used on a client-side Connection object, the ConnectionString property can include only the Remote Provider and Remote Server parameters.
The following table lists the default ADO provider for each Windows operating system:
| Default ADO provider | Windows operating system |
|---|---|
| MSDASQL (To improve the readability of source code, explicitly specify the provider name in the connection string.) |
Windows 2000 (32-bit) Windows XP (32-bit) Windows 2003 Server (32-bit) Windows Vista (32-bit) Windows Vista Service Pack 1 or later (32-bit and 64-bit) Windows versions after Windows Vista (32-bit and 64-bit) |
| No default. When an ADO application runs on the following operating systems and does not specify the provider explicitly, ADO returns the following error: "ADODB.Connection: provider is not specified and there is no designated default provider" |
Windows 2000 (64-bit) Windows XP (64-bit) Windows 2003 Server (64-bit) Windows Vista (64-bit) |
Applies To
See Also
ConnectionString, ConnectionTimeout, and State Properties Example (VB)
ConnectionString, ConnectionTimeout, and State Properties Example (VC++)
Appendix A: Providers