User request is to print manufacturer name maintained in Manufacturer table instead of MfgID. Lookup function in SSRS is used to get Manufacturer Name from Manufacturer table. Calculated field “MfgName” is added to POHeader dataset using the following expression:
=Lookup(Fields!Company.Value & Fields!Calc_MfgID.Value, Fields!Company.Value & Fields!MfgID.Value, Fields!Name.Value, “Manufacturer”)
Yes, you must also add the field in the query. Click on Query then the expression button, and add the field name to the query. That will also be the database name used in the screen above.
There are several examples on the forum if you search for them.