Why is a random String/varchar after the table name valid?

Question

Why is the following query a valid select ?

SELECT * from arelation somerandomtext;

The content of arelation does not matter, it just hast to be an existing view/table.

It returns the correct result, respectively the output of the select without the somerandomtext.

Why does this query do not throw an error/exception, is there no keyword (Group By, limit...) check ?

This is called a table alias and is a fundamental part of the SQL language -- required for instance to do self-joins. They are described in the Postgres documentation here (http://www.postgresql.org/docs/9.2/static/queries-table-expressions.html). — Gordon Linoff, Feb 05 '14 at 15:53
I always use(d) the the alias function with "as" , so this point did not came to my mind. — Akkusativobjekt, Feb 05 '14 at 16:04
I always use `as` for column aliases and never for table aliases -- probably the influence of Oracle earlier in my life (Oracle does not allow `as` for table aliases). — Gordon Linoff, Feb 05 '14 at 16:06
@GordonLinoff: Always using `AS` for *column aliases* (while the same is optional for table aliases) is also recommended for Postgres. Details [here](http://stackoverflow.com/questions/20229979/query-to-order-by-the-number-of-rows-returned-from-another-select/20230716#20230716). — Erwin Brandstetter, Feb 05 '14 at 16:23

score 0 · Accepted Answer · answered Feb 05 '14 at 15:57

0

Its an alias

i.e.

select c.id, c.* 
from products c

is valid syntax as it allows joins from a table to itself

i.e.

select c.id, p.id 
from products c inner join products p on p.id = c.id

answered Feb 05 '14 at 15:57

RoughPlace

1 Answers1