Add possibility to use fields instead of column for unique constraint

[alexander-schranz]

Currently when using a unique constraint like:

<unique-constraints>
    <unique-constraint columns="locale,product_key" />
</unique-constraints>

you are forced to define the column name for the fields e.g.:

<field name="productKey" column="product_key" type="string" nullable="true" unique="true"/>

if you don't do this and somebody configure another naming_strategy for your entity it will not longer work as the column does then not exist.

It would be a great feature if you could use unique-constraints based on field name and doctrine orm will read the column name from the configured field e.g.:

<unique-constraints>
    <unique-constraint fields="locale,productKey" />
</unique-constraints>

<!-- no column is needed here now -->
<field name="productKey" type="string" nullable="true" unique="true"/>

What do you think about this?

[beberlei]

This is a great idea, there are some caviats.

• What about associations? Is every join column added? That would make sense.
• Unique constraints need to be parsed after column/fields so that mapping info is available on CöassMetsdataInfo. This is not the case for all mapping drivers right now

[beberlei]

The logic of resolving Unique Constraint (and Index as well) fields to columns would need to be done in SchemaTool, because access to NamingStrategy is needed.

[Lustmored]

I took a shot at this and results are in #8523 - feedback is very welcome :)

[beberlei]

Fixed in #8629

[alexander-schranz]

@beberlei @Lustmored This is really great to hear! Thank you for implementing this 🙏