What does double bars (||) mean in SQL?
mysql, sql
Solution
double bars are concatination:
select 'hello' || ' ' || 'world' from dual;
yields
'hello world'
Problem
I'm trying to understand the following query: `select count(distinct Name || '' || Surname) from PEOPLE;` What does the double bars mean? What does this query do? In MySQL: `select "aaaaa" || '' || "bbbbb";` `+--------------------------+ | "aaaaa" || '' || "bbbbb" | +--------------------------+ | 0 | +--------------------------+ `