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A
relational expression returns the Boolean result of a relational
comparison of its operands.
Expression
|
Character representation
|
Returns
|
|---|
Relational
|
< 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.
|
|
> gt
|
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.
|
|
<= le
|
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.
|
|
>= ge
|
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
|
|---|
3 < 3
|
0 (false)
|
3 > 4
|
0 (false)
|
"abc" <= "def"
|
1 (true)
|
"def" > "abc"
|
1 (true)
|
12 >= 12
|
1 (true)
|
"true" < "false"
|
0 (false)
|
|
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