Customizing › Legacy Reports Customization › Report Template Reference › Variable Expressions › Variable Expression Remarks

Variable Expression Remarks

Variable names must be unique within a BLOCK statement and must not duplicate any column in the SELECT clause for the block. The same variable name can be used in different BLOCK statements but it cannot be repeated within a BLOCK statement.

Follow these syntax rules when including expressions in your report template:

• Use any valid C expression.
• Do not enclose variable or column names in quotes.
• Enclose string constants in single or double quotes.
• You can refer to a nested block, but only if it contains exactly one row.
• To include a column name that is the same as a keyword, precede the column name with a backslash (\). For example, ALIAS is a keyword and \alias is a column name.
• Use the dollar sign ($) to reference environment variables, such as $name, and to reference command line arguments, such as $n, where n is the position of the argument on the command line.
• To specify the number of command line arguments, use $#. For example, the following expression means that if the number of command line arguments is greater than one, use the additional argument as an argument; otherwise, set the value of the argument to an empty string. The report template itself is considered a command line argument. Therefore, the number of arguments is at least one.

  $# > 1 ? $1 : "
  

• Use ## to concatenate two strings, for example:

  title = "This is the " ## "first line. "
  

  long_name = fn	
  

  irst_name ## last_name
  

• The following casts are supported:
  • (number)
  • (string)
  • (date_time)
  • (duration)
• To reference a variable or column name in another block, precede the name with its block name and two colons. For example:

  blockname::column | variable-name