A predicate specifies a condition that SQL evaluates as true,
false, or unknown. Predicates are also called conditional
expressions. You can specify several different types of
predicates with different conditional operators. The different
types of predicates are:
o Basic
o BETWEEN
o Complex
o CONTAINING
o EXISTS
o IN
o IS NULL
o LIKE
o MATCHING
o Quantified
o SINGLE
o STARTING WITH
o UNIQUE
When you compare character value expressions, if automatic
translation has not been enabled, character sets of those value
expressions must be identical.
Some predicates have a specific behavior when used with the DEC
Multinational Character Set (MCS).
The following list describes multinational character set behavior
that applies to predicates:
o The character ñ is always treated as different from the
character n, in keeping with the practices of the Spanish
language. In a similar manner, the character ç is treated the
same as the character c, in keeping with the practices of the
French language.
o The character ü is treated the same as the character u for
many languages, but is sorted between the characters x and z
(with the ys) for Danish, Norwegian, and Finnish languages.
The following diagram shows the syntax for predicates:
(B)0[m[1mpredicate = [m
[1m [m
[1mqwqwqqqqqqqqwqwq> basic-predicate qqqqqqqqqqqqqqqqwqwqq> [m
[1m x mq> [1;4mNOT[m[1m qj tq> between-predicate qqqqqqqqqqqqqqu x [m
[1m x tq> containing-predicate qqqqqqqqqqqu x [m
[1m x tq> exists-predicate qqqqqqqqqqqqqqqu x [m
[1m x tq> in-predicate qqqqqqqqqqqqqqqqqqqu x [m
[1m x tq> is-null-predicate qqqqqqqqqqqqqqu x [m
[1m x tq> like-predicate qqqqqqqqqqqqqqqqqu x [m
[1mx[m [1mtq>[m [1mmatching-predicate[m [1mqqqqqqqqqqqqqu[m [1mx[m
[1m x tq> quantified-predicate qqqqqqqqqqqu x [m
[1m x tq> single-predicate qqqqqqqqqqqqqqqu x [m
[1mx[m [1mtq>[m [1munique-predicate qqqqqqqqqqqqqqqu[m [1mx[m
[1m x tq> starting-with-predicate qqqqqqqqu x [m
[1m x mq> (predicate) qqqqqqqqqqqqqqqqqqqqj x [m
[1m mqqqqqqqqqqqqqqqqqwq [1;4mAND[m[1m <qqwqqqqqqqqqqqqqqqqqqqqqqj [m
[1mmqq[m [1;4mOR[m [1m<qqj[m
NOTE
Except for the IS NULL, EXISTS, and SINGLE operators, if
either operand in a predicate is null, the value of the
predicate is unknown.
You cannot use a value of the LIST OF BYTE VARYING data
type for either operand in a comparison predicate. For more
information, see the LIST_OF_BYTE_VARYING HELP topic.
When you use the DEC_MCS or ASCII character set, SQL
compares character string literals according to the ASCII
collating sequence. Therefore, it considers lowercase
letters to have a greater value than uppercase letters,
and considers the letters near the beginning of the alphabet
to have a lesser value than those near the end.
'a' > 'A'
'a' > 'Z'
'a' < 'z'
'A' < 'z'
'A' < 'Z'
Additional Information:
explode
extract