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Used to compare the field value against a single value. Syntax | |
[{GT
LT
GE
LE
EQ
NE} value ["message"]] |
Parameters | |
- value
The value can be a field, constant, save field,
or a numeric expression, or it may be an index retrieve operand
within parentheses. Refer to "Statement Syntax" earlier in this
section for details. - message
Specifies a custom error message.
Discussion | |
You may use these statements to compare the contents of the
current field with a specified value. Any field can be compared
to the special comparison value $EMPTY that represents the lowest value for any data
type. The main rule governing these comparisons is that only values
of the same data type (character, numeric, or date) may be compared.
The comparison is performed from left to right after leading and
trailing blanks have been stripped from the field. Character Comparisons | |
If the two values being compared are not the same length,
the shorter is padded with blanks on the right until it is the same
length as the longer value. Then a comparison is made. In a character comparison, values are considered equal only
if each character matches. One value is less than another if, at
the point of mismatch, one character is numerically less than its
counterpart. Collating sequence order is used to determine the numeric
value of a character. (Refer to Appendix C for the USASCII collating
sequence; refer to the Language Support Reference Manual for
the collating sequences for all supported native languages.) For
example, for NATIVE-3000: - a
is greater than A - A
is greater than Δ - AA
is greater than A - AΔ
is greater than Δa
where Δ represents a blank. Numeric Comparisons | |
When numeric values are compared, they are first converted
to the HP 3000 internal representation of the number. Thus, a field
of type IMPn can be compared with NUMn, and NUMn or IMPn fields can be compared to type DIG fields. For
example, assume a field of type NUM 2 in which the value 123 has been entered. This value can be successfully
compared to the constant "123", or a field of type IMP, NUM, or DIG so long as the field contains the value 123 at run-time. For example: 123.000 (NUM3) is equal to 123 (DIG)
123.000 (NUM3) is equal to 12300 (IMP2) |
Date Comparisons | |
Two dates may be compared even if they differ in format and
order. This means that the date February 9, 1986, specified in the current field as 9 FEB 1986 (DMY) can be successfully matched against the
constant ! 02/09/86! whose order is MDY. Remember: a date constant
must always be in the order MDY. For example: 2/3/86 (MDY) is equal to Feb 3, 1986 (MDY)
2/3/86 (MDY) is equal to 86/2/3 (YMD) |
Example | |
- EQ F3
The current field value must exactly match the value
in F3 at run time. (Any leading or trailing blanks are
stripped from the value in both fields before the comparison is
made.) - GT 143.56
The current field value must be greater than 143.56 - NE $TODAY
A date entered in this field cannot be today's date. - GT "Cd"
The current field may contain any value greater
than Cd, such as D or Cde but it cannot be C or CD. Note that in NATIVE-3000 all uppercase characters
have a lower value than any lowercase character. - GE !5/7/86!
Any date including and after May 7, 1986 may be in current field. The date may be in any
of three formats: MDY, DMY, or YMD.
Native Language Support | |
NATIVE-3000 must be used to define values for date and numeric
fields within FORMSPEC. VPLUS will convert the value when the forms
file is executed to be consistent with the native language selected.
Single value comparisons (GT, GE, LT, LE, EQ, NE), specified within FORMSPEC may contain any character
in the 8-bit extended character set consistent with the selected
language ID. When the form is executed, the collating table for
the native language specified is used. For more information on Native Language
Support, see Section 8. |
