Adds an integrity rule between two data files on the server. This integrity rule has been previously described by a variable of type
Link description. All the client applications must comply with these integrity rules.
Remark: You have the ability to describe inter-database integrity rules.
The addition will be effective for the application that performed it once the connection has been closed and re-opened.
// Describe the connection
HDescribeConnection("MyConnection", "Julia", "Password", "MyHFServer", ...
"MyDatabase", hAccessHFClientServer, hORead)
// Open the connection
HOpenConnection("MyConnection")
...
MyLink is Link Description
// Describe the "LIVES" link
MyLink.Name = "LIVES"
MyLink.SourceFile = ".\MyDatabase\city.fic"
MyLink.LinkedFile = ".\MyDatabase\customer.fic"
MyLink.SourceKey = "CITYNAME"
MyLink.LinkedKey = "CUSTCITY"
// Default link (0-1, 0-1)
HAddLink("MyConnection", MyLink)
Syntax
<Result> = HAddLink(<Source connection> [, <Linked connection>] , <Link>)
<Result>: Boolean
- True if the operation was performed,
- False if a problem occurs. HErrorInfo is used to identify the error.
<Source connection>: Character string or Connection variable
Connection to which belongs the source file of the link. This connection corresponds to:
<Linked connection>: Optional character string or Connection variable
Connection to which belongs the linked file of the link. This connection corresponds to: If this parameter is not specified, both data files will belong to the same connection (<Source connection>).
<Link>: Link Description variable
Name of the Link description variable containing the characteristics of the link to create.
Remarks
Link description
In the link description, the names of the data files involved in the link (
SourceFile and
LinkedFile properties) must correspond to the physical names of the data files, relative to the Database used. The Database of each file is returned by <Source connection> and <Linked connection>
Miscellaneous
- HDescribeLink is used to describe a temporary link on an ISAM database (not in Client/Server mode) or for the client application only (not on the server).
- HDeleteLink is used to delete a link on the server.