static void pgDropSequence() {

// TODO(developer): Replace these variables before running the sample.

final String projectId = "my-project";

final String instanceId = "my-instance";

final String databaseId = "my-database";

pgDropSequence(projectId, instanceId, databaseId);

}

static void pgDropSequence(String projectId, String instanceId, String databaseId) {

try (Spanner spanner =

SpannerOptions.newBuilder().setProjectId(projectId).build().getService()) {

final DatabaseAdminClient dbAdminClient = spanner.getDatabaseAdminClient();

dbAdminClient

.updateDatabaseDdl(

instanceId,

databaseId,

ImmutableList.of(

"ALTER TABLE Customers ALTER COLUMN CustomerId DROP DEFAULT",

"DROP SEQUENCE Seq"),

null)

.get(5, TimeUnit.MINUTES);

System.out.println(

"Altered Customers table to drop DEFAULT from "

+ "CustomerId column and dropped the Seq sequence");

} catch (ExecutionException e) {

// If the operation failed during execution, expose the cause.

throw SpannerExceptionFactory.asSpannerException(e.getCause());

} catch (InterruptedException e) {

// Throw when a thread is waiting, sleeping, or otherwise occupied,

// and the thread is interrupted, either before or during the activity.

throw SpannerExceptionFactory.propagateInterrupt(e);

} catch (TimeoutException e) {

// If the operation timed out propagate the timeout

throw SpannerExceptionFactory.propagateTimeout(e);

}

}