Question

In JDBC I can use question marks for query parameters, like this:

"SELECT * FROM users WHERE login = ?"

and then

ps.setString(1, "vasya");

But how can I query for list of logins:

"SELECT * FROM users WHERE login IN ?"

suppose, I have

List<String> logins = ...

What should I type there:

ps.setWhat(1, what);

I could rewrite query as:

"SELECT * FROM users WHERE login = ? OR login = ? OR login = ?"

and then call setString in loop, but I’d like to know if it is possible to pass a set of elements as single param in query.

Maybe there are vendor-specific extensions?

Answer 1

There are vendor specific ways to do that, therefore it would be good to know what database you use. I know solutions for PostgreSQL and H2. I implemented this feature in the H2 database, so that’s what I know best:

H2 Database

PreparedStatement prep = conn.prepareStatement(
  "select * from users where login in (select * from table(x int = ?))");
prep.setObject(1, new Object[] { "1", "2" });
ResultSet rs = prep.executeQuery();

PostgreSQL

WHERE login = ANY(?)

Then set the parameter to an array of values using PreparedStatement.setArray(..) (not setObject as for H2).