select 'Hello' || ' World' from dual;
select concat('Hello',' World') from dual;
select CONCAT('A','B');
select 'Hello' || ' World';
select concat('Hello',' World');
select 'Hello' + ' World' ;
select concat('Hello',' World') ;
select 'Hello' || ' World' from dual;
select concat('Hello',' World') from dual;
select CONCAT('A','B');
select 'Hello' || ' World';
select concat('Hello',' World');
select 'Hello' + ' World' ;
select concat('Hello',' World') ;