Connect to DataSnap Server (FireDAC)

From RAD Studio
Jump to: navigation, search

Go Up to Database Connectivity (FireDAC)

This topic describes how to connect to Multi-Tier DataSnap servers.

Supported Versions

The Multi-Tier FireDAC DataSnap driver supports:

  • DataSnap servers built with RAD Studio 2007 and later.
  • DataSnap clients built with RAD Studio XE2 Enterprise and later.

Client Software

FireDAC statically links the Embarcadero DataSnap dbExpress driver, so no additional files and DLLs are required. Supported are RAD Studio XE2 Enterprise and later.

Driver Linkage

To link the DataSnap driver:

Connection Definition Parameters

To connect to the DataSnap server, most applications require you to specify DriverID, Protocol, Server, Port, User_Name, Password (see Defining Connection (FireDAC) for details).


Parameter Description Example value

The protocol used to connect to the DataSnap server. It can be one of the following values:

  • TCP/IP. Connect using TCP/IP protocol. This is the default protocol.
  • HTTP. Connect using HTTP protocol.
Server Server address to connect to.
Port The TCP/IP or HTTP port on which the DataSnap server is listening. The default value for TCP/IP is 211, for HTTP - 8080. 211
User_Name DataSnap server authentication user name.
Password DataSnap server authentication user password.
BufferKBSize Buffer size in kilobytes to use in order to read and write operations. The default value is 32Kb. 64
Filters Client filters used to store the filter configuration. The default value is empty.
URLPath HTTP only. URL path used for HTTP DataSnap Service when the http protocol is used. The default value is empty.
DatasnapContext HTTP only. Path toward the DS HTTP Service used to compose the URL. The current convention is: ''. The user can change or delete the "datasnap" word from it. The default value is 'datasnap/'.
DSProxyHost HTTP only. The host through which you can proxy requests, or an empty string if you do not use a proxy. The default value is empty.
DSProxyPort HTTP only. The port on the proxy host through which you can proxy requests. It is ignored if DSProxyHost is not set. The default value is empty.
DSProxyUsername HTTP only. User name for proxy authentication. The default value is empty.
DSProxyPassword HTTP only. Password for proxy authentication. The default value is empty.
DSAuthenticationScheme HTTP only. DataSnap authentication scheme. Used in conjunction with the DataSnap user name and password for authentication using the HTTP protocol. Set to "basic" in order to send User_Name / Password values using basic HTTP authentication, in addition to sending these values in the DBX connection string. Basic HTTP authentication may be used to pass credentials to an inter-process DataSnap HTTP tunnel server. The default value is empty.
LoginTimeout HTTP only. Connect time-out value. The value provides the number of milliseconds the client waits for the connection to be possible. The value provides the time-out for the first server response acknowledgment rather than for the entire connect/authenticate phase. It should be used in order to avoid application freeze when it is possible to attempt connections to older DataSnap Server versions or to different applications that do not acknowledge the current communication protocol. The default value is 10000ms.
CommunicationTimeout HTTP only. Time-out value in milliseconds for a response after the connection is established. The default value is empty.

Use Cases

Connect to the local DataSnap server with default settings:


Connect to the DataSnap server using the TCP/IP protocol running on a local host:


See Also