Cross-Database Referencing

The functionality described in this section exists in order to minimize problems of cross-database referencing when Design databases are deleted and rebuilt from macros.

All Draft elements with DDNM, IDLN, or IDNM reference attributes also have 'system' text attributes DDNX, IDLX, and IDNX respectively. These three attributes can be queried but not set by the user.

Draft will always use the DDNM, IDLN and IDNM attributes; values in DDNX, IDLX and IDNX will be ignored. Setting a DDNM, IDLN or IDNM attribute will also cause the associated ‘system’ text attribute (that means, DDNX, IDLX and IDNX respectively) to be set to the name of the Design element referenced, so long as it is named.

The following UPDATE commands exist to aid updating of a Draft database following rebuilding of an associated Design database:

UPDATE element_identifier REFS

UPDATE element_identifier NAMES

The first of these will change the DDNM, IDLN, and IDNM attributes of element_identifier, and all elements below it in the Draft database hierarchy, to match the values obtained from the associated text attributes. This means that if a Design database is deleted and rebuilt then, so long as those elements referenced from Draft databases are all named, references in Draft databases can easily be kept up to date.

The second command will change the DDNX, IDLX, and IDNX attributes to match the values obtained from the associated reference attributes. This option has been included primarily to allow a full set of these new text attributes to be generated for existing Draft databases. In each case no change will occur if a value cannot be obtained from the name/reference encoding/decoding process. The element_identifier can be omitted, in which case the current element will be assumed.

During the updating process warning messages will be output whenever an attribute is changed or when Draft attempts to change an attribute but is unable to generate the required name or reference to do so. These messages will be of the form:

VSEC 2 of /VIEW2: IDLN attribute updated to /ZONE1.PIPES

GLAB 1 of /D1/S1/V1/LAYER1: unable to update DDNX attribute