Represents the relationship between two value expressions.
Sometimes called a Boolean expression, conditional expressions
are used in the WITH clause of the record selection expression.
The value of a conditional expression is true, false, or missing.
The two types of conditional expressions are:
o Those that express a relationship between two value
expressions, using a relational operator
For example, the expression SH.SALARY_AMOUNT > 50000 is true
if the value in the SALARY_AMOUNT field of the SALARY_HISTORY
record is greater than 50000. When Oracle Rdb evaluates this
expression, it examines the relationship between the two value
expressions, SH.SALARY_AMOUNT and 50000.
o Those that express a characteristic of a single value
expression
For example, E.EMPLOYEE_ID MISSING is true if there is no
value in the EMPLOYEE_ID field of an EMPLOYEES record.
The RDML conditional expressions are:
- ANY
- BETWEEN
- CONTAINING
- MATCHING
- MISSING
- Relational Operators
- STARTING WITH
- UNIQUE
For more information and the syntax diagram of each of these
expressions, see the individual HELP entries.
1 – Format
(B)0[mqqqwq> conditional-expr qqqqqqqqqqqqqqqqq>qqqqqqqqqqqqqqwqqqqqq>
tqqqqqqqqqqqqqqqqqqqqq> [4mNOT[m qq> conditional-expr qqqqu
tq> conditional-expr q> [4mAND[m qq> conditional-expr qqqqu
mq> conditional-expr q> [4mOR[m qq> conditional-expr qqqqj
(B)0[mconditional-expr =
qwqqq> value-expr qq> rel-operator qq> value-expr qqwqq>
tqqq> any-clause qqqqqqqqqqqqqqqq>qqqqqqqqqqqqqqqqqu
tqqq> between-clause qqqqqqqqqqqq>qqqqqqqqqqqqqqqqqu
tqqq> containing-clause qqqqqqqqq>qqqqqqqqqqqqqqqqqu
tqqq> matching-clause qqqqqqqqqqq>qqqqqqqqqqqqqqqqqu
tqqq> missing-clause qqqqqqqqqqqq>qqqqqqqqqqqqqqqqqu
tqqq> starting-with-clause qqqqqq>qqqqqqqqqqqqqqqqqu
mqqq> unique-clause qqqqqqqqqqqqq>qqqqqqqqqqqqqqqqqj
(B)0[mrel-operator =
qqqqwqq> [4mEQ[m qqqwqqqqq>
tqq> = qqqu
tqq> [4mNE[m qqqu
tqq> <> qqqu
tqq> [4mGT[m qqqu
tqq> > qqqu
tqq> [4mGE[m qqqu
tqq> >= qqqu
tqq> [4mLT[m qqqu
tqq> < qqqu
tqq> [4mLE[m qqqu
mqq> <= qqqj