MySQL offers the ability to use regular expressions to perform complex searches against your data. A regular expression is a tool that provides for a concise and flexible way to identify strings of text based on user-defined patterns.
The DB2 CONCAT function will combine two separate expressions to form a single string expression. It can leverage database fields, or explicitly defined strings as one or both expression when concatenating the values together.
The DB2 COALESCE function returns the value of the first non-NULL expression. The COALESCE function takes a comma separated list of arguments which are evaluated in the order in which they are specified and returns the first non-NULL value found.