|In the datawindow expressions painter it can be useful to reference other
rows within the datawindow result set. When building expressions when you use a column
name you reference the data item in the current row. This is very powerful as PowerBuilder
executes the expression for every row in turn based on the relative row position.
useful feature is the ability to reference other rows from the current relative row. For
example in a list of customers and orders you could check to see if the customer name has
changed and display a bitmap to indicate the change of customer. You can do this with out
creating a group band at break of customer which allows you to put the customer name next
to the first order! Something you cannot do with a group band.
To access the properties you would code the access to the column with an array
subscript following the column name. Only this is a special subscript that is relative to
the current row:
bitmap( if( customer[ -1 ] = customer, '', 'smile.bmp' )