sql

All things SQL and JDBC...
isak 2020-09-09T16:45:47.271Z

Is it possible to do this via next.jdbc? (Processing more than one ResultSet)

String SQL = "SELECT 1; SELECT * FROM nonexistentTable;";
try (Statement statement = connection.createStatement();) {
    // Does not throw an exception on execute().
    boolean hasResult = statement.execute(SQL);
    while (hasResult) {
        try (ResultSet rs = statement.getResultSet()) {
            while (rs.next()) {
                System.out.println(rs.getString(1));
            }
        }
        // Moves the next result set that generates the exception.
        hasResult = statement.getMoreResults();
    }
} catch (SQLException e) {
    e.printStackTrace();
}

isak 2020-09-09T16:48:48.271800Z

Oh never mind, I see it: {:multi-rs true}

seancorfield 2020-09-09T17:11:57.272800Z

@isak The test suite only tests that against MS SQL Server, although it does have a test on stored procs returning multiple result sets that runs on a few more types of DB https://github.com/seancorfield/next-jdbc/blob/develop/test/next/jdbc_test.clj#L446

isak 2020-09-09T17:22:38.273100Z

I'm on SQL Server, seems to work well :thumbsup::skin-tone-2:

seancorfield 2020-09-09T20:23:39.275300Z

seancorfield/next.jdbc {:mvn/version "1.1.588"} -- https://github.com/seancorfield/next-jdbc -- adds next.jdbc.plan/select! and next.jdbc.plan/select-one! to make some common usages of plan easier to write (based on my usage on next.jdbc/plan at work). See next.jdbc.plan docs https://cljdoc.org/d/seancorfield/next.jdbc/1.1.588/api/next.jdbc.plan and updated examples in the second half of https://cljdoc.org/d/seancorfield/next.jdbc/1.1.588/doc/getting-started#plan--reducing-result-sets

dharrigan 2020-09-09T20:29:38.275900Z

that's pretty neat!

seancorfield 2020-09-09T20:35:46.276600Z

I found I was writing (reduce (fn [_ row] (reduced (f row))) nil (jdbc/plan ...)) all over the place...

seancorfield 2020-09-09T20:36:37.277700Z

...and then I looked at all my plan uses and found that (into [] (map f) (jdbc/plan ...)) was also pretty common. Except in a few places where it was (into #{} (map f) (jdbc/plan ...))

seancorfield 2020-09-09T20:38:13.279300Z

...and then I realized that we also commonly turn some result sets into lookup hash maps based on the primary key and one other column... so that is now (plan/select! ds (juxt :id :name) ["select..."] {:into {}})

dharrigan 2020-09-09T20:38:49.279600Z

It's a great addition to the library

seancorfield 2020-09-09T20:39:13.280Z

It's the first thing that's really grown out of daily usage...