Returns a TRUE value if the first of two expressions
is less than the second.
Syntax
expression { LT | < } expression
|
-
expression
- A constant, field or variable name, or expression. The expressions
on either side of the LT or < = must be the same data type, although
one can be an integer and the other decimal.
Example
This
procedure displays information for those Item records
whose OnHand value is less than the Allocated value:
r-lt.p
FOR EACH Item NO-LOCK WHERE Item.OnHand < Item.Allocated:
DISPLAY Item.ItemNum Item.ItemName Item.OnHand Item.Allocated.
END.
|
Notes
- By
default, the AVM 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 the
AVM accesses during the session, except when the AVM uses or modifies
pre-existing indexes. If you do not specify a collation with the -cpcoll startup
parameter, the AVM 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, the AVM 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 such comparisons are
case insensitive in ABL. That is, upper-case and lower-case characters have
the same sort value. 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 cannot compare data of different DATE, DATETIME, and DATETIME-TZ
data types to each other using LT. You must first convert different
date and datetime data types to the same data type before doing a
comparison between them.
- 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 the AVM raises a run-time
error.
- You cannot use LT to compare one CLOB field to another.
- You can use LT to compare two enums, including both ABL and .NET enums, as long as they
are the same enum type. LT compares the underlying numerical values of the
enumerators.