Chapter 5 Files/Folders needed: \Chapter5\Samples \Chapter5\Labs

Understanding Expressions Defining Expressions Working with Report Variables Enhance Formatting by Using Expressions Understanding Lookup, LookupSet, and Multilookup Functions Expression Samples

 Many uses ◦ Create aggregates ◦ Compute complex values ◦ Dynamically hide and show values ◦ Format based on a value  Simple expressions =Fields!Product.Value  Expression with multiple functions =IIf((RowNumber(Nothing) Mod 2)=0, "LightGrey“, "LightSteelBlue")

 Expressions written in Visual Basic (with some unique rules)  Many code parts are case sensitive  Double quotes (" ") surround string values ◦ Be careful of “Smart Quotes” when copying from MS Word  No underscore (_) for line continuation ◦ Use a hard return alone to make code more readable  Data type conversions and functions use standard VB naming

 Accessed through Expression menu options, or the function button.  Type code directly in the box, or double-click a value or item  Red wavy underlines may indicate errors ◦ Some errors won’t be obvious until you preview the report

 Options change based on Category field selected

 Added through Report Properties dialog box  Accessed from the Report menu  Evaluated once per report  Used anywhere in the report

 Returns data from a second dataset  Each requires 4 input parameters ◦ The source key or names to lookup ◦ The destination key or name to match on ◦ The expression to be returned ◦ The destination dataset name

=Lookup(Fields!BusinessEntityID.Value, Fields!SalesPersonID.Value, Fields!TotalSales.Value, "SalesPersonTotalSales")  Returns one value for each source key of name ◦ For example – returns an account description located in an Excel spreadsheet to match the account code listed in the dataset that is bound to a table.

 Returns all values that match the source key or name  Passes a set (or array) back to the expression ◦ For example, locate in a different dataset, all order dates for a particular customer, and list them as a single value in a new column. =Join(LookupSet(Fields!BusinessEntityID.Value, Fields!SalesPersonID.Value,Fields!SalesOrderID.Value, "SalesOrders“ ), “, “ & vbCrLf)

 Handles many-to-many relationships between the two datasets  The source may be an array that needs to be split ◦ Example – Look up a list of countries where each employee has placed orders. The list of order numbers associated with the employee must be split and then an array of countries will be returned.  The source may be a multi-valued parameter

 Derived columns based on an expression ◦ Add a weight range title to a new column ◦ Add a member level based on early purchases  Format based on an expression ◦ Change the background color of every other row ◦ Change the font color for rows with high sales

 Exercise 1: Using Expressions to Work With Dates  Exercise 2: Using Expressions to Manipulate Data