Update operation sets boolean fields to NULL instead of false, violating non-null constraint

[vichu]

Update operation sets boolean fields to NULL instead of false, violating non-null constraint

[bevzzz]

tl;dr: Try using .Value() method to control which value gets appended to the query.
The following should work:

db.NewUpdate().
  Model(entity).
  Column("is_active").
  Value("is_active", "false"). // will substitute to is_active = false
  WherePK().
  Exec(ctx)

This is a workaround, because the behaviour you've described looks buggy. For more about that, read on.

---

This happens because any field that has a bun:"default:x" tag also gets a "nullzero" tag.:

bun/schema/table.go

Lines 378 to 381 in 8a43835

	if s, ok := tag.Option("default"); ok {
	field.SQLDefault = s
	field.NullZero = true
	}

Why? Because for INSERT queries bun needs to be able to correctly decide to append DEFAULT placeholder for a field that has a zero value:

bun/query_insert.go

Lines 335 to 338 in 8a43835

	case (f.IsPtr && f.HasNilValue(strct)) || (f.NullZero && f.HasZeroValue(strct)):
	if q.db.features.Has(feature.DefaultPlaceholder) {
	b = append(b, "DEFAULT"...)
	} else if f.SQLDefault != "" {

That's helpful, even though not all dialects support this feature (looking at you, SQLite).
But then, once we try to set a field that has a default value to false (zero boolean value) in UpdateQuery we get the bug you've described. It happens here:

bun/schema/field.go

Lines 97 to 99 in 8a43835

	if (f.IsPtr && fv.IsNil()) || (f.NullZero && f.IsZero(fv)) {
	return dialect.AppendNull(b)
	}

I think adding a HasDefault bool field to schema.Field and using it checking for SQLDefault != "" in the InsertQuery instead would be a good long-term solution.