Part-18 STRING FUNCTION | CONCAT | CONCAT_W IN Postgres

To concatenate two and more strings into one, you can use ||  the string concatenation operator 

select 'MY'  ||' ' ||'LOVE' || ' ' || 'MY' || ' ' || 'INDIA' ;

Output :"MY LOVE MY INDIA"

Ex:- Find the email domain name from email address using substring or position sting function .

do 
$$
declare email varchar;g1 varchar; 
begin
g1:='tarun@capgemini.com';
email:=(
select substring(g1,
 (position('@' in g1)+1),
length(g1) - position('@' in g1)));
raise notice '%',email;
end;
$$

Ex:- How to repeat star at  email domain name from email address using substring or position sting function 

do 

$$

declare email varchar:='tarun@capgemini.com';g1 varchar;

begin

g1:=(select substring(email,1,2) ||repeat('*',5) || substring(email,position('@' in email),

   length(email)- position('@' in email)+1));

raise notice '%' ,g1;
end
$$