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A
relational expression returns the Boolean result of a relational
comparison of its operands.
|
Expression
|
Character representation
|
Returns
|
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Relational
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< lt
|
True (1) when the first operand is less
than the second operand, and false (0) when the first operand is
larger than the second operand.
|
|
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> gt
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True (1) when the first operand is greater
than the second operand, and false (0) when the first operand is
less than the second operand.
|
|
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<= le
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True (1) when the first operand is less
than or equal to the second operand, and false (0) when the first
operand is greater than the second operand.
|
|
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>= ge
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True (1) when the first operand is greater
than or equal to the second operand, and false (0) when the first
operand is less than the second operand.
|
The following special cases also apply when using relational
operators:
-
If either operand is null valued, a null comparison is
performed. Null-valued operands compare identically whenever both
operands are null and the relational operator is less-than-or-equal
or greater than or equal, and compare differently otherwise.
-
If both operands are string valued, a locale-sensitive lexicographic
string comparison is performed on the operands. Otherwise, if they
are not both null, the operands are promoted to numeric values,
and a numeric comparison is performed.
These are examples of using the relational expression:
|
Expression
|
Returns
|
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3 < 3
|
0
(false)
|
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3 > 4
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0
(false)
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"abc" <= "def"
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1
(true)
|
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"def" > "abc"
|
1
(true)
|
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12 >= 12
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1
(true)
|
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"true" < "false"
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0
(false)
|
|
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