Modify a database

After you've designed a database, it's not unusual to go back and make changes, either to add new elements or to delete things that are no longer needed. There are a number of features to help you do this.

Replace

When modifying an existing design, replace is a particularly useful feature. Simply drag a new raw data file on top of an existing raw data file to replace and your existing mappings will be retained. This saves considerable time and effort - to do this manually would require lots of un-mapping and re-mapping of individual dimensions, properties. etc. 

• Identically named columns in the new file will remain mapped.
• New columns can appear anywhere in the new file. They'll need to be mapped manually.
• Any removed columns will be automatically unmapped.
• Columns do not have to be in the same order.
  
  

Unmap vs. delete

When designing a database, the act of dragging and dropping a column will create both the structure and mapping at the same time. You are able to delete  the structure, unmap it ,  or both, unless the value has a foreign mapping (see point 3 below). 

Mapping	The blue border means that 'Value' has been mapped from the raw data that appears at the bottom of your screen. Use the  to unmap. There are three potential outcomes: It becomes unmapped and deleted: It will disappear completely. It becomes unmapped but the structure remains: See 2. Structure. It becomes unmapped but a foreign mapping remains. See 3. Foreign Mapping.
2. Structure	In this situation, 'Value' exists as a structural element only. It isn't mapped, and you won't see it in Phocas after building the database. Often a structure exists as part of a template or a previous design. It often serves as a placeholder, awaiting a future mapping. Use delete  to permanently delete it.
3. Foreign Mapping	The blue dot means that 'Value' is mapped from a different raw data source - not the one that appears at the bottom of your screen. There is no ability to unmap or delete from here - first you'll need to locate the correct raw data file (it could be in another stream, or a different raw data file in the current stream).

Working with missing raw data

Even if you have the ideal database design, it is possible for raw data files to get moved, deleted, or renamed independently, which could cause a build error.  

From Administration > Databases, choose your database and then click Design.  If there is a mismatch between the design and raw data, an error similar to the following will appear.

Click OK to close the error message. On the Designer screen the streams that have missing raw data will be red. As shown below, hover, to display the name of the missing data.

You have the following options to address the issue of missing data:

• Restore: Put the missing raw data item back. This could mean re-uploading it, re-syncing it and checking the file name.  
• Replace: You can easily drag a new raw data file on top of the missing red file. The file will turn blue again, and any existing mappings will be retained. See Replace.
• Remove: If it is no longer needed, you can remove the red raw data file by clicking the 'X'.