Field help (ABVEXPLNK)

This field is defined as one or more calculated expressions separated by a semi colon. Each expression is evaluated, and the result used to identify the value of the key used to perform the join. When multiple joins are authorized, only the first elements of the key can be given.

In the expressions, constants can be used, as well as fields coming from the tables previously defined in the link list.

It should be noted that the link expression can be empty. In this case, the table is simply on-line without the current records being read. This can be useful if for example a function defined by a developer (syntax func PROGRAMME.FONCTION) is used. This function can be used to read the information in tables of this type.