Mapping information for the Create Cross-Reference tool can also be provided in a separate file as an Excel spreadsheet. This file can be created for instances where the Create Cross-Reference tool will not be able to automatically match feature class and field names. It would be useful if, for example, source Road_L should be loaded into target RoadL, because the target does not contain Road_L.
The external mapping file you can create allows you to customize the way the source workspace is mapped to the target. When this file is used for mapping the source to the target workspace, the Create Cross-Reference tool does not attempt to map them to one another; it only uses the information provided in the mapping file. This also means that all tables and fields in the source workspace that need to be mapped to the target must be included. If they are not, they are omitted during the load process.
This mapping file can contain 1–3 worksheets, as follows:
- Data Mapping—Contains information on mapping tables from the source dataset to the target
- Field Mapping—Contains information on mapping fields in source tables to the target tables
- Value Mapping—Allows you to override default values for fields with range domains
Each worksheet's name corresponds to the name of a table in the cross-reference database, except that spaces are allowed in the worksheet names. Also, instead of numeric identifiers for tables in datasets and their fields, you can provide actual names.
Dataset Mapping worksheet
On the Dataset Mapping worksheet, you can list the tables in the source dataset and specify what tables they should be mapped to in the target dataset. For instance, you could indicate that the RoadL table in the source dataset should be mapped to the Road table in the target dataset. If there are conditions you want to apply to the source data as it is loaded into the target space, you can also add WHERE clauses and a code that corresponds to the subtype.
Columns that must be on the Dataset Mapping worksheet are described in the table below.
| Column name | Description |
|---|---|
Id | A unique identification number for each row |
SourceDataset | Name of the table in the source dataset |
TargetDataset | Name of the destination table in the target dataset |
WhereClause | Contains an optional WHERE clause that determines which records are imported from the source |
Subtype | A number that corresponds to a subtype in the target feature class into which the records are going to be imported |
Field Mapping worksheet
On the Field Mapping worksheet, you can specify which fields in the source tables should be mapped to the target tables. This can be configured when the name of the field in the source does not match the target. For instance, the name of the length field could be "len_" in the source and "len" in the target. There could also be more obvious differences in field names, such as the name field is "NAM" in one workspace and "NAM1" in the other workspace. On this table, you need to provide an ID number for the table in the dataset, which can be found in the Id column on the Dataset Mapping table.
Columns that must be on the Field Mapping worksheet are described in the table below.
| Column name | Description |
|---|---|
Id | A unique identification number for each row |
DatasetMapId | An identification number that contains the identifier of the dataset from the Dataset Mapping worksheet, Id column |
SourceField | The name of the field in the source table |
TargetField | The name of the destination field in the target table, which can be different from the source table |
WhereClause | Contains an optional WHERE clause that determines which fields are imported from the source. |
Value Mapping worksheet
With the Value Mapping worksheet, you can override values contained in a source field that would not be considered valid in the target field. For instance, you can replace all occurrences of the value "OPR" with "Operational". The FieldMapId value corresponds to the Id column on the Field Mapping table.
Columns that must be on the Value Mapping worksheet are described in the table below.
| Column name | Description |
|---|---|
Id | A unique identification number for each row |
FieldMapId | An identification number that contains the identifier of the field from the Field Mapping worksheet, Id column |
FromValue | The value contained in the source field that you want to overwrite |
ToValue | The value that you want to use to replace the FromValue |