`mapping_types` config seems to be ignored on `diff`

[OskarStark]

`mapping_types` config seems to be ignored on `diff`

[goetas]

From my understanding of mapping types, types and comments...

• mapping_types are rules used by DBAL to convert SQL types to DBAL types.
• types are rules used by DBAL to convert DBAL types into PHP Types (or better, to choose a converter that maps "SQL data" to PHP types/data).

as example:

• postgres bigserial is converted into DBAL's bigint (thanks to built in mapping_types)
• DBAL's bigint is later converted in PHP's string (thanks to built in types)

Thus in your case i would expect something as:

        mapping_types:
            vector: LLPhantVectorType
        types:
            LLPhantVectorType: LLPhant\Embeddings\VectorStores\Doctrine\VectorType

The fact that your implementation of VectorType returns an array is is unknown to doctrine.

The comment is used to infer a Doctrine type when there are multiple doctrine types mapped on the same SQL type. The classical example is:

Consider an SQL type varchar(255), that type can be used as the Php's string, MyEnum (a backed enum that uses strings as cases) or any PHP type that can be serialized into a string with max 255 chrs.

When DBAL encounters a vector SQL type, needs to decide which DBAL Type assign to it. If a comment is found, it will try to find that type, if not it will find a default.

You might have configs defined as follows:

        mapping_types:
            vector: LLPhantVectorType
        types:
            LLPhantVectorType: LLPhant\Embeddings\VectorStores\Doctrine\VectorType
            GoetasVectorType: GoetasVectorType

In this case, both GoetasVectorType and LLPhant\Embeddings\VectorStores\Doctrine\VectorType want to use a SQL vector, but DBAL needs to a way to decide which type to instantaite when an SQL column of type vector is found.

GoetasVectorType will have to override requiresSQLCommentHint. Columns that use GoetasVectorType will have a comment, columns that use LLPhant\Embeddings\VectorStores\Doctrine\VectorType will not.

When DBAL finds an SQL vector type will check for a comment, when found will try to instantiate the type in the comment. If no comment is found, will try to instantiate the type defined in the configs.