[cloud-spanner-leaderboard-java]:

In the codelab's “5. Load Data” section, compare the Java snippet and App.java stack trace with the linked Cloud Spanner commit-timestamp documentation. Update the instructions so the documented operation matches the API behavior, then verify the sample's timestamp insertion no longer produces the reported binding exception.

5. Load Data

To auto-populate the Timestamp column with the timestamp of exactly when the "Insert" transaction takes place, you can instead insert the Java constant Value.COMMIT_TIMESTAMP like in the following code snippet:

.bind("Timestamp")
.to(Value.COMMIT_TIMESTAMP)

This is instruction doesn't seem to be right.

Exception in thread "main" com.google.cloud.spanner.SpannerException: UNKNOWN: Mutation.COMMIT_TIMESTAMP cannot be bound as a query parameter
        at com.google.cloud.spanner.SpannerExceptionFactory.newSpannerExceptionPreformatted(SpannerExceptionFactory.java:151)
        at com.google.cloud.spanner.SpannerExceptionFactory.newSpannerException(SpannerExceptionFactory.java:45)
        at com.google.cloud.spanner.SpannerImpl$TransactionRunnerImpl.runInternal(SpannerImpl.java:1365)
        at com.google.cloud.spanner.SpannerImpl$TransactionRunnerImpl.run(SpannerImpl.java:1317)
        at com.google.cloud.spanner.SessionPool$PooledSession$1.run(SessionPool.java:408)
        at com.google.codelabs.App.insertScores(App.java:118)
        at com.google.codelabs.App.insert(App.java:59)
        at com.google.codelabs.App.main(App.java:247)
Caused by: java.lang.IllegalArgumentException: Mutation.COMMIT_TIMESTAMP cannot be bound as a query parameter
        at com.google.common.base.Preconditions.checkArgument(Preconditions.java:141)
        at com.google.cloud.spanner.Statement$Builder$Binder.handle(Statement.java:103)
        at com.google.cloud.spanner.Statement$Builder$Binder.handle(Statement.java:100)
        at com.google.cloud.spanner.ValueBinder.to(ValueBinder.java:99)
        at com.google.codelabs.App$2.run(App.java:155)
        at com.google.codelabs.App$2.run(App.java:119)
        at com.google.cloud.spanner.SpannerImpl$TransactionRunnerImpl.runInternal(SpannerImpl.java:1349)

As per doc[1], mutation instead of statement should be used in such case.

https://cloud.google.com/spanner/docs/commit-timestamp#insert-row