Relational operators in PowerBuilder

Description

PowerBuilder uses relational operators in boolean expressions
to evaluate two or more operands. Logical operators can join relational
expressions to form more complex boolean expressions.

The result of evaluating a boolean expression is always true or false.

The following table lists relational and logical operators.

Table 4-2: PowerBuilder relational and logical operators
Operator	Meaning	Example
=	Equals	`if Price=100 then Rate=.05`
>	Greater than	`if Price>100 then Rate=.05`
<	Less than	`if Price<100 then Rate=.05`
<>	Not equal	`if Price<>100 then Rate=.05`
>=	Greater than or equal	`if Price>=100 then Rate=.05`
<=	Less than or equal	`if Price<=100 then Rate=.05`
NOT	Logical negation	`if NOT Price=100 then Rate=.05`
AND	Logical and	`if Tax>3 AND Ship <5 then Rate=.05`
OR	Logical or	`if Tax>3 OR Ship<5 then Rate=.05`

Usage

Comparing strings

When PowerBuilder compares strings, the comparison is case
sensitive. Trailing blanks are significant.

For information on comparing strings regardless
of case, see the functions Upper and Lower.

To remove trailing blanks, use the RightTrim function.
To remove leading blanks, use the LeftTrim function.
To remove leading and trailing blanks, use the Trim function.
For information about these functions, see RightTrim, LeftTrim,
and Trim.

Decimal operands

Relational operators that operate on numeric values (including =, >, <, <>, >=,
and <=) can take decimal operands. The precision of
the decimal operand is maintained in comparisons.

Null value evaluations

When you form a boolean expression that contains a null value,
the AND and OR operators behave
differently. Thinking of null as undefined (neither true nor false)
makes the results easier to calculate.

For more information about null values,
see “NULL values “.

Examples

Case-sensitive comparisons

If you compare two strings with the same text but different
case, the comparison fails. But if you use the Upper or Lower function,
you can ensure that the case of both strings are the same so that
only the content affects the comparison:

City1 = "Austin"

1	City1 = "Austin"

City2 = "AUSTIN"

1	City2 = "AUSTIN"

IF City1 = City2 ...              // Returns FALSE

1	IF City1 = City2 ... // Returns FALSE

City1 = "Austin"

1	City1 = "Austin"

City2 = "AUSTIN"

1	City2 = "AUSTIN"

IF Upper(City1) = Upper(City2)... // Returns TRUE

1	IF Upper(City1) = Upper(City2)... // Returns TRUE

Trailing blanks in comparisons

In this example, trailing blanks in one string cause the comparison
to fail:

City1 = "Austin"

1	City1 = "Austin"

City2 = "Austin       "

1	City2 = "Austin "

IF City1 = City2 ...             // Returns FALSE

1	IF City1 = City2 ... // Returns FALSE

Logical expressions with null values

In this example, the expressions involving the variable f,
which has been set to null, have null values:

boolean d, e = TRUE, f

1	boolean d, e = TRUE, f

SetNull(f)

1	SetNull(f)

d = e and f   // d is NULL

1	d = e and f // d is NULL

d = e or f    // d is TRUE

1	d = e or f // d is TRUE

Document get from Powerbuilder help

Thank you for watching.

Powerbuilder Documentation 12.5

August 9, 2023

Was this article helpful?

Connection Information

Relational operators in PowerBuilder – PB Docs 125