A constant consists of literal text or predefined text. The report processor has access to predefined constants so that when you include them in an expression, the values they represent are substituted in the expression before it is evaluated.
You can create and modify paginated report definition (.rdl) files in Report Builder and in Report Designer in SQL Server Data Tools. Each authoring environment provides different ways to create, open, and save reports and related items.
In an expression, literal text is text that is in double quotation marks. You can also type text directly into a text box without double quotation marks if it is not part of an expression. If the text box value does not begin with an equal sign (=), the text is treated as literal text. The following table shows several examples of literal text in an expression.
|Constant||Display text||Expression text|
|Report run at:||<<Expr>>||
|Adventure Works Cycles||Adventure Works Cycles||Adventure Works Cycles|
|[Bracketed display text]||\[Bracketed display text\]||[Bracketed display text]|
You can use constants defined in Report Definition Language (RDL) in an expression. In the Expression dialog box, constants appear when you create an expression for a report property that only accepts certain valid values, also known as enumerated types. The following table shows two examples.
|TextAlign||Valid values for aligning text in a text box.||General, Left, Center, Right|
|BorderStyle||Valid values for a line added to a report.||Default, None, Dotted, Dashed, Solid, Double, DashDot, DashDotdot|
Visual Basic Constants
You can use constants defined in the Visual Basic run-time library in an expression. For example, you can use the constant DateInterval.Day. The following expression for the date January 10, 2008 returns the number 10:
You can use constants defined in .NET Framework common language run-time (CLR) classes in an expression. The following table shows an example of a system-defined color.
|MistyRose||When you create an expression for a report property that is based on background color, you can specify a color by name. Valid names are listed in the Expression dialog box.|