[Postgres] How to make a text field UUID auto generated?

[mariovalney]

There's no UUID field for collections.
If you need one, by now you should add a text field and generate it on runtime, but it's not a optimus approach.

[mariovalney]

For people from the future (and Google).

We can use beforeSchemaInit hook on payload.config.ts:

postgresAdapter({
  pool: {
    connectionString: process.env.DATABASE_URI || '',
  },
  beforeSchemaInit: [
    ({ schema, adapter }) => {
      for (const tableName in adapter.rawTables) {
        const table = adapter.rawTables[tableName]

        for (const fieldName in table.columns) {
          const column = table.columns[fieldName];
          const defaultValue = column?.default ?? '';

          if (defaultValue === 'uuid') {
            delete column.default;

            column.type = 'uuid';
            (column as any).defaultV7 = true;
          }
        }
      }

      return schema;
    },
  ],
})

Note: tested with Postgres 18: maybe you will need to change defaultV7 to defaultRandom on early versions.

And just add it to collection's field:

  {
    type: 'text',
    name: 'custom_uuid',
    unique: true,
    required: true,
    index: true,
    defaultValue: 'uuid',
  },

Inspired here.