In Java-SQL columns, fields of type String are stored as Unicode.
When a Java-SQL String field is assigned to a SQL data item whose type is char, varchar, nchar, nvarchar, or text, the Unicode data is converted to the character set of the SQL system. Conversion errors are specified by the set char_convert options.
When a SQL data item whose type is char, varchar, nchar, or text is assigned to a Java-SQL String field that is stored as Unicode, the character data is converted to Unicode. Undefined codepoints in such data cause conversion errors.