Q: Why did I fail to create a thematic map when I used ‘+’ to connect to fields to construct the expression in SuperMap iDesktop 8C?
A: There are some rules for connecting fields while constructing the expression for thematic maps. For the UDB file datasource, you need to use ‘|’to connect two fields. For the oracle and sql server datasources, you can use ‘+’ to connect two fields. If the fields connected are now string fields, you need to convert the fields with the Str function to convert them into string fields first, Name + Str(SMID) for instance.