Macromedia Flash (SWF) Movie Created by Camtasia Studio 2. How to create a SQL union of 2 queries. How to use NZ() function and what it is for. Main page listing all tutorials. How to query out particular days. How to add a running sum column. Use of the 'instr' or instring function. Parameter input box in a query. Addition of a 'slider' Normalization and cleansing of data. Finding duplicates.