On long-running projects such as those where you gather the same type of data on a monthly basis, it is possible that an axis may change during the life of the project. For example, if a shop goes out of business, you might replace it with a new shop and re-use the code that represented the old shop in the data for the new shop.

If you want the multiproject database to include the original element and its replacement, you must create an axis that contains the full list of element texts. Elements which no longer exist in the database should have conditions that cannot be met, so that the element appears in the database but has no respondents in it.

In the example, if Safeway is replaced by Asda, you could write the new axis as:

If you merge the constituent databases on element texts, and use the latest database as the master, your multiproject database will contain six supermarkets. If, instead, you wanted the figures for Asda in the multiproject database to include the figures for Safeway, give them the same unique ID. For more information on unique ids (uniqid), see Matching element texts in Quanvert multiproject databases.