how do I make a select which always returns zero rows

Question

I want to determine if a column exists in a table for any jdbc driver.

In order to know the columns in a table, I have to make a query to the table and then get the ResultSetMetaData for the info, but this is pretty expensive in like 99% of times.

In mysql I have:

SELECT * FROM tablename LIMIT 0,0

In Intersystems caché I have:

SELECT TOP 0 * FROM tablename

But, for example, in JavaDB I cannot apply any limit at all.

Is there any generic query that would give me the same result and still be fair with the DB performance?

Thanks in advance.

Answer 1

SELECT * FROM table_name WHERE 1 = 2;

Answer 2

select * from tablename where 1 != 1

Answer 3

Unrelated, but if you just need the columns in MySQL, you can run SHOW FIELDS FROM tablename. This returns columns and the associated info.

Answer 4

SELECT * FROM tableName WHERE 'You' = 'Smart'

Answer 5

...or you could just use the DatabaseMetaData route.

There's a "getColumns" method that does what you need without creating a resultset.