Relational Operators¶
All data types can be compared by using relational operators and the result is returned as a BOOLEAN value.
Relationship operators are binary operators. Two compared data types must be of the same type or they must support implicit conversion.
Table 1 lists the relational operators provided by DLI.
Operator | Result Type | Description |
|---|---|---|
A = B | BOOLEAN | If A is equal to B, then TRUE is returned. Otherwise, FALSE is returned. This operator is used for value assignment. |
A == B | BOOLEAN | If A is equal to B, then TRUE is returned. Otherwise, FALSE is returned. This operator cannot be used for value assignment. |
A <=> B | BOOLEAN | If A is equal to B, then TRUE is returned. Otherwise, FALSE is returned. If A and B are NULL, then TRUE is returned. If A or B is NULL, then FALSE is returned. |
A <> B | BOOLEAN | If A is not equal to B, then TRUE is returned. Otherwise, FALSE is returned. If A or B is NULL, then NULL is returned. This operator follows the standard SQL syntax. |
A != B | BOOLEAN | This operator is the same as the <> logical operator. It follows the SQL Server syntax. |
A < B | BOOLEAN | If A is less than B, then TRUE is returned. Otherwise, FALSE is returned. If A or B is NULL, then NULL is returned. |
A <= B | BOOLEAN | If A is less than or equal to B, then TRUE is returned. Otherwise, FALSE is returned. If A or B is NULL, then NULL is returned. |
A > B | BOOLEAN | If A is greater than B, then TRUE is returned. Otherwise, FALSE is returned. If A or B is NULL, then NULL is returned. |
A >= B | BOOLEAN | If A is greater than or equal to B, then TRUE is returned. Otherwise, FALSE is returned. If A or B is NULL, then NULL is returned. |
A BETWEEN B AND C | BOOLEAN | If A is greater than or equal to B and less than or equal to C, then TRUE is returned. Otherwise, FALSE is returned. If A, B, or C is NULL, then NULL is returned. |
A NOT BETWEEN B AND C | BOOLEAN | If A is less than B or greater than C, TRUE is returned; otherwise, FALSE is returned. If A, B, or C is NULL, then NULL is returned. |
A IS NULL | BOOLEAN | If A is NULL, then TRUE is returned. Otherwise, FALSE is returned. |
A IS NOT NULL | BOOLEAN | If A is not NULL, then TRUE is returned. Otherwise, FALSE is returned. |
A LIKE B | BOOLEAN | If A matches B, then TRUE is returned. Otherwise, FALSE is returned. If A or B is NULL, then NULL is returned. |
A NOT LIKE B | BOOLEAN | If A does not match B, then TRUE is returned. Otherwise, FALSE is returned. If A or B is NULL, then NULL is returned. |
A RLIKE B | BOOLEAN | This operator is used for the LIKE operation of JAVA. If A or its substring matches B, then TRUE is returned. Otherwise, FALSE is returned. If A or B is NULL, then NULL is returned. |
A REGEXP B | BOOLEAN | The result is the same as A RLIKE B. |