IBM Integration Bus, Version 10.0.0.3 Operating Systems: AIX, HP-Itanium, Linux, Solaris, Windows, z/OS


ESQL logical operators

The logical operators AND, OR and NOT.

ESQL provides the following logical operators:

Operator AND
The result is the logical AND of the two operands. Both operands must be Boolean values.
Operator OR
The result is the logical OR of the two operands. Both operands must be Boolean values.
Operator NOT
The result is the logical NOT of the operand, which must be a Boolean value.

NULL and UNKNOWN values are treated as special values by these operators, according to the following rules:

The evaluation of the individual clauses in a statement that includes the AND or OR logical operators is stopped as soon as the overall statement can be resolved. For example, see the following statements:
  • IF A OR B THEN ...
    • If A is false, B is evaluated.
    • If A is true, B is not evaluated because the statement is already resolved to be true.
  • IF A AND B THEN ...
    • If A is true, B is evaluated.
    • If A is false, B is not evaluated because the statement is already resolved to be false.

The result of AND and OR operations is defined by the following table:

Value of P Value of Q Result of P AND Q Result of P OR Q
TRUE TRUE TRUE TRUE
TRUE FALSE FALSE TRUE
TRUE UNKNOWN UNKNOWN TRUE
FALSE TRUE FALSE TRUE
FALSE FALSE FALSE FALSE
FALSE UNKNOWN FALSE UNKNOWN
UNKNOWN TRUE UNKNOWN TRUE
UNKNOWN FALSE FALSE UNKNOWN
UNKNOWN UNKNOWN UNKNOWN UNKNOWN

The result of NOT operations is defined by the following table.

Operand Result of NOT
TRUE FALSE
FALSE TRUE
UNKNOWN UNKNOWN

ak01036_.htm | Last updated 2015-11-26 23:59:54