SQL选择如何插入列名并提供值

Question

How do you add a column to a select statement and assign a static value, when the column does not exist?

name | address | vacationing | Zipcode

So for the example columns above, I would like to create the column on the fly of "vacationing" whose value will be assigned No for each record. I don't want to insert this column in the table permanently.

Thanks

Answer 1

Do you mean something like this?

SELECT Name, Address, 'No' AS Vacationing, Zipcode
FROM MyTable

Answer 2

select name, address, 'No' as vacationing, Zipcode from mytable;

Answer 3

You cannot have a column that only exists for some of the records, and not all of them. Either create it permanently or if you like, create another table and JOIN it using the name or id or whatever it is you use in this table as a primary key.