4.7 Repair attribute data - LUPMISManual

4.7 Repair Attribute Data

Level of expertise required for this Chapter: Expert; general Map Maker training

With merging, importing, adjusting Ids and other database related operations, the correct link to the attribute data (DBF file) might have to be re-established!

Always when cutting or deleting polygons in a DRA file with attached database (DBF file), the ‘geometry’ has to be updated.

Frequent checking should be carried out on features (points, lines or polygons), where attribute data are know. For example, an altitude line, whose value is known, should be data-querried.

The standard procedure to guarantee a clean link between the graphical data and the attribute data is through a database extract:

1. Main menu > Utilities > Database utilities > Make database extract for DRA > Select folder and source DRA file > Open > Select source DBF file (if major changes were made, last one before changes took place) > Open > Choose link column window: Select ID > OK > Save as window: Specify new DBF file name > Save

2. Load graphical (DRA) file into the live layer, without data: For example, through Main menu > Edit > Load file into live layer > Select folder and source DRA file

3. Main menu > Live layer data > Merge data table with live data > Select DBF file, previously created > Open > Choose link column window: Select ID > Leave both two option ticked > OK > Pick columns to import window: Select all > OK

4. Save as usual, including the DBF file.

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While the process above is recommended for all repair, there is also an alternative approach:

1. Load original file into live layer

2. Edit, for example cut with cutter (or with cut file) or delete feature(s).

3. Save as temporary file 1 (for example, Temp1)

4. Make database extract: Main menu > Utilities > Database utilities > Make database extract for DRA > Select temporary file 1 (edited DRA file, Temp1 in example above) > Select previous (original) DBF file > Choose link column window: ID > OK > Save as window: Specify temporary file 2 (only DBF) > Save

5. Load DRA file as temporary file 1 with database of temporary file 2, into live layer: Main menu > Edit > Load file into live layer with data > Select temporary file 1 (as DRA, Temp1 in example above) > Open > Select temporary file 2 (as DBF, Temp2 in example above) > Open > Choose link column window: ID > OK

6. Save as usual

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Note: Additional tool to fix attribute data or corrupted links between graphical (DRA) and attribute (DBF) file exists with the tool Object/Data linker (Main menu > Edit > Live layer data > Show Object/Data linker). This very powerful tool requires expert knowledge of database management and is not part of this Manual.

Some topology checks, which can be performed with the Object/Data linker:
A) Check topology is ok in all to-be-merged layers: Main menu > Edit > Live layer data > Show Object/Data linker > check (no entries at unlinked object Ids or unlinked database Ids) > Close
B) Check in all layers, that there are no identical ID numbers between the different to-be-merged files (through Show Object/Data linker). If necessary, renumber with Live layer actions window: Ids and labels > Amend labels and Ids > OK > Renumber Ids starting from … > OK
C) Link all object IDs: Main menu > Edit > Live layer data > Show Object/Data linker > There should be some items in the column ‘Unlinked object IDs (and no features in the column ‘Unlinked database Ids’) > Create new database entries for unlinked objects > Close
D) Check that all links are ok: Main menu > Edit > Live layer data > Show Object/Data linker > check (no entries at unlinked object Ids or unlinked database Ids) > Close
E) Assign new consecutive number to all Ids: Right-mouse > Live layer actions > Ids and labels > Amend labels and Ids > OK > Renumber starting from 1 > OK
F) If an error is detected (wrong value, or 0, or no entry at all), following repair is recommended:
F.1. Create an empty (‘dummy’) attribute file from the vector layer: Main menu > Utilities > Database utilities > Generate database from DRA > Select folder and file to be repaired > Generate database window: Don’t select any columns > OK > Give a new file name for this temporary file (e.g. temp1) > Save
F.2. Load the damaged vector layer into the live layer and merge with the previously created database: From Program manager window: Add layer > ….  > Copy layer to live layer > OK.
Main menu > Edit > Live layer data > Merge data table with live data > Select dummy data file just created (e.g. temp1) > Open > Choose link column window: Select ID, leave 2 boxes at the bottom half ticked > OK > Pick columns to import window: Tick ID > OK
F.3. Superimpose existing database (attribute data) to this repaired layer:
Main menu > Edit > Live layer data > Merge data table with live data > Select original data file > Open > Choose link column window: Select ID, leave 2 boxes at the bottom half ticked > OK > Pick columns to import window: Select all > OK