expression || expression String concatenation (two vertical bars). If either string is the NULL value, the string is treated as the empty string for concatenation.
expression + expression Alternative string concatenation. When using the + concatenation operator, you must ensure the operands are explicitly set to character data types rather than relying on implicit data conversion.
The result data type of a string concatenation operator is a LONG VARCHAR. If you use string concatenation operators in a SELECT INTO statement, you must have a Large Objects Management option license or use CAST and set LEFT to the correct data type and size.
See “REVERSE function [String]” for information and usage.
