Release 10.1A: OpenEdge Development:
Progress 4GL Reference

LT or < operator

Returns a TRUE value if the first of two expressions is less than the second.

Syntax

expression { LT | < } expression

expression

A constant, field name, variable name, or expression. The expressions on either side of the LT or < = must be of the same data type, although one can be an integer and the other can be a decimal.

Example

This procedure displays information for those item records whose on-hand value is less than the allocated value:

r-lt.p

FOR EACH item WHERE on-hand < allocated: DISPLAY item.item-num item-name on-hand allocated. END.

Notes

By default, Progress uses the collation rules you specify to compare characters and sort records. The collation rules specified with the Collation Table (-cpcoll) startup parameter take precedence over a collation specified for any database Progress accesses during the session, except when Progress uses or modifies pre-existing indexes. If you do not specify a collation with the -cpcoll startup parameter, Progress uses the language collation rules defined for the first database on the command line. If you do not specify a database on the command line, Progress uses the collation rules with the default name "basic" (which might or might not exist in the convmap.cp file).
If either of the expressions is the Unknown value (?), then the result is the Unknown value (?); if both of the expressions are the Unknown value (?), then the result is FALSE.
You can compare character strings with LT. Most character comparisons are case insensitive in Progress. That is, upper-case and lower-case characters have the same sort value. However, it is possible to define fields and variables as case sensitive (although it is not advised, unless strict ANSI SQL adherence is required). If either expression is a field or variable defined as case sensitive, the comparison is case sensitive and “Smith” does not equal “smith.”
Characters are converted to their sort code values for comparison. Using the default case-sensitive collation table, all uppercase letters sort before all lowercase letters (for example, a is greater than Z, but less than b.) Note also that in character code uppercase A is less than [ , \ , ^ , _, and  ’ , but lowercase a is greater than these.
You can use LT to compare DATE, DATETIME, and DATETIME-TZ data. The data type that contains less information (that is, a DATE value contains less information than a DATETIME value, and a DATETIME value contains less information than a DATETIME-TZ value) is converted to the data type with more information by setting the time value to midnight, and the time zone value to the session's time zone (when the data type does not contain the time or time zone). Comparisons with DATETIME-TZ data are based on Coordinated Universal Time (UTC) date and time.
You can use LT to compare a LONGCHAR variable to another LONGCHAR or CHARACTER variable. The variable values are converted to -cpinternal for comparison and must convert without error, or Progress raises a run-time error.
You cannot use LT to compare one CLOB field to another.