Techniques for accessing data

Two techniques

There are two ways to access data values in a DataWindow control:

Both methods allow you to access data in any buffer and to get original or current values.

Which technique to use

The technique you use depends on how much data you are accessing and whether you know the names of the DataWindow columns when the script is compiled:

Table 4-1: Which technique to use when accessing data

If you want to access

Use

A single item

Either an expression or a method. Both are equally efficient when referring to single items.

NoteException If you want to use a column’s name rather than its number, and the name is not known until runtime, use a method; methods allow you to name the column dynamically.

More than one item, such as:

  • All the data in a column

  • A block of data specified by ranges of rows and columns

  • Data in selected rows

  • All the data in the DataWindow

An expression. Specifying the data you want in a single statement is much more efficient than calling the methods repeatedly in a program loop.

What’s in this section

The rest of this section describes how to construct expressions for accessing DataWindow data. The section “Syntaxes for DataWindow data expressions” provides reference information on the syntaxes for data expressions.

For information on methods

For information about using methods for accessing data, see SetItem, GetItemDate, GetItemDateTime, GetItemDecimal, GetItemNumber, GetItemString, and GetItemTime in Chapter 9, “Methods for the DataWindow Control.”