Could hammer support generated columns?

[jameszhujian]

Hi there,
We want to add a generated column to our schema, but hammer doesn't like the syntax. The DDL is like:
expiry TIMESTAMP AS (IF(status IS NULL, updated_at, '10000-01-01 00:00:00 UTC')) STORED

Thanks.

James

[daichirata]

Thanks for the report. hammer uses https://pkg.go.dev/cloud.google.com/go/spanner/spansql for parsing DDL.

spansql can correctly parse the following DDLs.

CREATE TABLE user (
  Id STRING(20) NOT NULL,
  FirstName STRING(50),
  LastName STRING(50),
  Age INT64 NOT NULL,
  FullName STRING(100) AS (ARRAY_TO_STRING([FirstName, LastName], " ")) STORED,
) PRIMARY KEY (Id);

But, when I try to parse the next DDL, I seem to get an error.

CREATE TABLE user (
  Id STRING(20) NOT NULL,
  FirstName STRING(50),
  LastName STRING(50),
  Age INT64 NOT NULL,
  AgeAbove18 INT64 AS (IF(Age > 18, Age, NULL)) STORED;
) PRIMARY KEY (Id);

Detailed conditions are not known, but https://github.com/googleapis/google-cloud-go/tree/main/spanner/spansql needs to be modified to correct this.

[neglect-yp]

I've created a PR for this issue. googleapis/google-cloud-go#6341

However, there are few conditional expressions that are not yet supported.

[neglect-yp]

You can try hammer v0.5.10, which has been released with added support for IF and IFNULL expressions. It will work fine > if you are not using NULLIF or COALESCE expressions (or other unsupported syntax).

#37 (comment)

[daichirata]

This change is included in the v0.5.10 release.