Cannot load index information for functional indexes

[pcriv]

After upgrading to 0.28.0 from 0.27.1, I'm getting the following error when trying to generate code from my schema:

unable to fetch table data: unable to load indexes: sql: Scan error on column index 2, name "column_name": converting NULL to string is unsupported

[stephenafamo]

Can you share more details?

• What driver are you using?
• What does your config look like?
• An example schema to reproduce this

[pcriv]

driver: mysql config:

---
mysql:
  dsn: "root:@tcp(localhost:3306)/dname"
  output: internal/dbgen
  pkgname: dbgen
  except:
    schema_migrations:
relationships:
  # hidden

About the schema, I cannot share the whole schema, but is there any specific part that you have in mind that could help?

[stephenafamo]

is there any specific part that you have in mind that could help?

The part that helps to reproduce the error.

Perhaps you can use the only configuration to generate table-by-table till you find the offending table and share a schema of that table?

[pcriv]

That's a good idea! I'll try that and keep you updated, thanks!

[pcriv]

I think I found the offensive line. FYI, the only option did not work, it was failing no matter which table I added, so I had to get creative

This is a bit of an ugly one:

KEY `index_batches_tags_workspace_id` (((cast(json_unquote(json_extract(`tags`,_utf8mb4'$.workspaceId')) as char(255) charset utf8mb4) collate utf8mb4_bin)))

[stephenafamo]

This probably has something to do with #237

Can you perhaps take a look @mbezhanov?

[mbezhanov]

Sure, I'll have a look right away.

[mbezhanov]

Okay, I've identified the issue. This is a functional index (it indexes expressions rather than columns), so column_names in information_schema.statistics is indeed NULL. I'm working on a fix.

[pcriv]

Thanks for the quick reactions @mbezhanov and @stephenafamo ❤️

[mbezhanov]

No problem at all, and sorry for my oversight!