Record Linking
The system links records to each other in certain situations. For example, when your organization orders a copy of a book, the system links the bibliographic and order records. Similarly, when a patron checks out a book, the system links the item record to the patron record.
Some related records are "soft linked". For more information on soft links, see Soft Linking Records in ERM.
The following table describes how the different record types are linked together. (Authority records have no links.)
| Record type | Must be linked? | Links to... | Limits |
|---|---|---|---|
| Authority | No | Does not link to other records. | N/A |
| Bibliographic | No | One or more course, holdings, item, patron, order, or volume records. Bibliographic records can soft link to course or patron records. Bibliographic records are associated with resource records through the holdings/checkin record. The holdings/checkin record is linked to the bibliographic record and soft linked to the resource record. |
Maximum of 300 holdings records linked to one bibliographic record. Maximum of 5000 item records linked to one bibliographic record. Maximum of 200 order records linked to one bibliographic record. Maximum of 5000 volume records linked to one bibliographic record. Maximum of 1000 bibliographic records linked to one item record. No limit on the number of bibliographic records linked to a course record. |
| Central Bibliographic | No | One or more institution records. | Maximum of 5000 institution records linked to one central bibliographic record. |
| Contact | No | One or more resource records. | No limit. |
| Course | No | Item records. Course records can soft link to one or more bibliographic records. |
Maximum of 350 item records linked to one course record. No limit on the number of bibliographic records linked to a course record. |
| Holdings/Checkin | Yes | One bibliographic record. If library uses monographic holdings, also can link to multiple item records. Holdings/checkin records can link to resource and vendor records. Holdings/checkin records populate the holdings field from the coverage data if your library has acquired a product such as ERM or WebBridge. |
Maximum of 300 holdings/checkin records linked to one bibliographic record. Maximum of 5000 item records linked to one holdings/checkin record. |
| Institution | Yes | One central bibliographic record. | Maximum of 5000 institution records linked to one central bibliographic record. |
| Invoice | No | Does not link to other records. Invoice records can soft link to one vendor record. |
N/A |
| Item | Yes | One or more bibliographic, course, or patron records. If the library uses monographic holdings, also can link to one or more holdings/checkin records. If the library uses volume records, an item can link to only one volume record and that volume record must link to the same bibliographic record as the item. |
Maximum of 5000 item records linked to one bibliographic record. Maximum of 5000 item records linked to one holdings/checkin record. Maximum of 2100 item records linked to one patron record. Maximum of 5000 item records linked to one volume record. Maximum of 350 item records linked to one course record. |
| License | Yes | One or more resource records. | Maximum of 1000 license records linked to one resource record. |
| Order | Yes | One and only one bibliographic or resource record. Order records can soft link to one vendor record. Order records can link or soft link to resource records. |
Maximum of 1000 order records linked to one bibliographic record. Maximum of 1000 order records linked to one resource record. Maximum of 100 funds linked to one order record. |
| Patron | No | Item records. Patron records can link to bibliographic or item records, as well as be soft linked from section records. |
Maximum of 2100 item records linked to one patron record. |
| Program | No | One or more section records. | Maximum of 1000 section records linked to one program record. |
| Resource | No | One or more license, order, or contact records. Resource records are soft linked to holdings/checkin records. See Managing Electronic Resources with ERM for more information on resource record linking. |
Maximum of 1000 license records linked to one resource record. Maximum of 1000 contact records linked to one resource record. Maximum of 1000 order records linked to one resource record. |
| Section | Yes | One and only one program record. Section records can soft link to one or more patron records. |
Maximum of 1000 section records linked to one program record. |
| Vendor | No | Does not link to other records. Order, invoice, and holdings records can soft link to vendor records. |
N/A |
| Volume | Yes | One bibliographic record and one or more item records. | Maximum of 5000 item records linked to one volume record. Maximum of 5000 volume records linked to one bibliographic record. |