Multiselect option is not visible for the existing attribute

Question

Previous developers created attribute with attribute code : is_outlet_available .

Now we need Multiple Select option for that attribute. But the Multiple Select option is not visible now. Is there any way we can select Multiple Select option for that attribute instead of creating new attribute?

Answer 1

You can use Setup/Patch to update the attribute input and type. Note: Multiple select require backend_type: varchar.

Update: change the backend type, You migh have to migrate the option value of that attribute.

Sample:

$eavSetup->updateAttribute('catalog_product','is_outlet_available', 'input', 'multiselect');
$eavSetup->updateAttribute('catalog_product', 'is_outlet_available', 'backend_type', 'varchar');
$eavSetup->updateAttribute('catalog_product', 'is_outlet_available', 'backend', \Magento\Eav\Model\Entity\Attribute\Backend\ArrayBackend::class);