I want to join few attributes in select statement as one for example
select id, (name + + surname + + age) as info from users
this doesn t work, how to do it? I m using postgreSQL.
Postgres uses || to concatenate strings; your query needs to be:
select id, (name || || surname || || age) as info from users
It should be the key just above the Enter key on a full keyboard, but on mine it s not a sold line - there s a break in the middle of it. You have to hold the Shift key to get the character (called a pipe, btw).
I believe the ANSI standard concatenation operator is: ||
SELECT id, name || || surname || || age AS info FROM users
It perfectly might be dependent of the database I would take a look for a concatenation function for the database you are running the select for.
Example. Mysql: CONCAT(name, surname, age).
You may need to cast the fields to a common type before concatenating. In T-SQL for example this would read.
Select id, Cast(name as varchar(50)) + + Cast(surname as varchar(50)) + +
Cast(age as varchar(3)) As info From Users
|| is used for this purpose.
Use it like select name || ||surname || ||age as info from users
If you re using mysql or oracle then try CONCAT function:
SELECT id, CONCAT(name, , surname, , age) as info FROM users
That should work as is, but in general it is better not to do too much concatenation sql side if you can help it; rather return all the columns and concat them on the other end.
What are the data types you are using? You may need to CAST / CONVERT into (n)varchar
Make sure your data types are similar and convert any datatypes to string as necessary:
select id, (name + + surname + + convert(varchar(3),age)) as info from users
Works fine in most databases I know, although you probably have to CAST the age field to be TEXT. The exact method for doing this depends on the database you re using, which you did not specify.
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