A string function is a function that supplies an alphanumeric value as a result.
<string_function> ::=
<string_spec> || <string_spec>
| <string_spec> & <string_spec>
| SUBSTR (<string_spec>,<expression>[,<expression>])
| LFILL (<string_spec>,<string_literal>[,<unsigned_integer>])
| RFILL (<string_spec>,<string_literal>[,<unsigned_integer>])
| LPAD (<string_spec>,<expression>,<string_literal>[,<unsigned_integer>])
| RPAD (<string_spec>,<expression>,<string_literal>[,<unsigned_integer>])
| TRIM (<string_spec>[,<string_spec>])
| LTRIM (<string_spec>[,<string_spec>])
| RTRIM (<string_spec>[,<string_spec>])
| EXPAND (<string_spec>,<unsigned_integer>)
| UPPER (<string_spec>)
| LOWER (<string_spec>)
| INITCAP (<string_spec>)
| REPLACE (<string_spec>,<string_spec>[,<string_spec>])
| TRANSLATE (<string_spec>,<string_spec>,<string_spec>)
| MAPCHAR (<string_spec>[,<unsigned_integer>][,<mapchar_set_name>])
| ALPHA (<string_spec>[,<unsigned_integer>])
| ASCII (<string_spec>)
| SOUNDEX (<string_spec>)
| GET_OBJECTNAME (<string_literal>)
| GET_OWNER (<string_literal>)
string_spec, expression, string_literal, unsigned_integer, mapchar_set_name
Concatenation (x||y bzw x&y), SUBSTR(x,a,b), LFILL(x,a,n), RFILL(x,a,n), LPAD(x,a,y,n), RPAD(x,a,y,n), TRIM(x,y), LTRIM(x,y), RTRIM(x,y), EXPAND(x,n), UPPER(x)/LOWER(x), INITCAP(x), REPLACE(x,y,z), TRANSLATE(x,y,z), MAPCHAR(x,n,i), ALPHA(x,n), ASCII(x), SOUNDEX(x), GET_OBJECTNAME(x,o), GET_OWNER(x,o)