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sequencehsqldb

Initialize a sequence in Hsqldb Datamanager

I am using hsqldb-1.8.0.10 and I want to use the sequence feature. I launch the DatabaseManager from the jar file as follows:

java -cp lib/hsqldb.jar org.hsqldb.util.DatabaseManager

I run these requests:

CREATE TABLE test (ID bigint)
CREATE SEQUENCE seq START WITH 1 INCREMENT BY 1
SELECT NEXT VALUE FOR seq FROM test

There is no output. If I insert some rows in the table, it works fine and displays 1.

Is it a normal comportment? Is there a way to get a value with an empty table?

Solution

  • Yes, this is normal. The statement below returns one row for each row of the table. It doesn't matter what you put between SELECT and FROM (except aggregate functions).

     SELECT <anything you put here> FROM test

    The NEXT VALUE FOR seq is like a function that return the next value each time it is called.

    If you do not have to use version 1.8.0, use the latest version of HSQLDB as it supports a more extensive syntax.