Hi I am using h2 database with mode as oracle , so need to define create alias for Oracle function to_number On running the JUnit test case, the error comes : Invalid SQL script for the create alias statement.
Am I missing any dependency. I have added dependency of H2 database. Am able to setup schema using create table also Or can anyone suggest any alternative to functions like to_number and initcap that are Oracle support. On Sat, 29 Oct, 2022, 6:52 pm 'Mark Raynsford' via H2 Database, < [email protected]> wrote: > On 2022-10-29T18:38:19 +0700 > Andreas Reichel <[email protected]> wrote: > > > > Well, it depends what you want. > > But your MAP key should be corresponding with your Table PRIMARY KEY. > > > > If you have a compound Primary Key, then your Map also must have a > > compound Key (not just an Integer) and you would likely need to build a > > Key Class implementing Comparable, Equals and Hash. > > I understand that, I think we may have gone down the wrong fork in the > road. :) > > My question is about being able to declare one or more maps in a way > that will permit efficient (ie, not O(N)) to a subset of the keys in > a map. > > Let's assume then that I have this as a composite primary key: > > record GroupMember(int group, int member); > > And I have a map: > > MVMap<GroupMember, GroupMember> m; > > This matches the definition of the `t` table I posted in the original > email; the primary key and the row are the same value. > > How, then, do I efficiently ask for all rows that have a given group > value g? > > I would have to do something like this: > > var members = new ArrayList<Integer>(); > for (var entry : m.entrySet()) { > if (entry.getKey().group() == g) { > members.add(entry.getKey().member()); > } > } > return members; > > This works, but is O(N) in the size of the map, whereas it _could_ be > O(1) (assuming that map access are O(1)) if I could declare the map > as being something analogous to: > > MVMap<Integer, Set<Integer>> m; > > I assume that I'm _not_ supposed to do this, given that MVStore doesn't > come with DataType definitions for any collection types. > > Now obviously H2 is using MVStore internally for database tables, and > there it's obviously possible to have something like: > > create table t (group integer not null, member integer not null); > create index t_groups on t (group); > > ... and then have "SELECT * FROM t where t.group = ?" be an indexed > scan instead of a seq scan over the entire t table... But what exactly > would an equivalent MVStore configuration look like? > > -- > Mark Raynsford | https://www.io7m.com > > -- > You received this message because you are subscribed to the Google Groups > "H2 Database" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/h2-database/20221029132144.3b269aa0%40sunflower.int.arc7.info > . > -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/h2-database/CAK_22rZUn2CHMAgY-%3DcgA5tPv9%3D-jZz6ipkjqt0dawwONxr2ow%40mail.gmail.com.
