You can use + arithmetic operator to add two numbers, concatenate two strings, or add an interval to a DATE value.
Syntax:
expr + expr
When you add two integer values the result of the operation also has an integer value.
Example:
| Expression | Result | Result Type |
| 3 + 1 | 4 | Integer |
When you use + for string operand the result of the operation is the concatenated string.
Example:
| Expression | Result | Result Type |
| 'Ab' + 'c' | 'Abc' | String |
When you add an integer to a DATE value, PL/HQL adds the number of days to the DATE and the result of the operation is a DATE value.
Example:
| Expression | Result | Result Type |
| DATE '2014-12-31' + 1 | DATE '2015-01-01' | DATE |