Gorm one to one relationship based on multiple conditions

I am trying to implement a relationship in GORM that isn't simply based on id foreign key. A quick overview of database structure:

There is an order table which contains a tableNo column which is generally an integer but can also be a string (some tables are say B2). The table number needs to be matched up to a table (row) in the table table (sorry for confusing database table names). This relationship is done through venueId and tableNo.

If I was to write this relationship in MySQL we could join the tables using the following:

select o.tableNo, o.venueId, t.title, t.venueId from order o
left join table t on t.venueId = o.venueId
where replace(t.title, "Table #", '') = o.tableNo
order by o.createdAt desc;

In my model I have written the following:

type Order struct {
	Id      int    `json:"id,omitempty"`
	VenueId int    `gorm:"column:venueId" json:"venueId,omitempty"`
	TableNo string `gorm:"column:tableNo" json:"tableNo,omitempty"`
	Table   Table  `gorm:"references:Title,foreignKey:TableNo" json:"table"`
}

type Table struct {
	Id      int    `gorm:"column:id" json:"id,omitempty"`
	VenueId int    `gorm:"column:venueId" json:"venueId,omitempty"`
	Title   string `gorm:"column:title" json:"title,omitempty"`
}

Clearly there are certain things missing, i.e replace on the tableNo in the table model. I also need to connect the table object to the order using the venueId. Gorm currently gives an error need to define a valid foreign key for relations or it need to implement the Valuer/Scanner interface anyway even though the relationship I specified isn't complete.

My current solution is just to manually execute the query as this is what GORM would do anyway with a preload. (i.e order.Table = query_result)

If you have any suggestions as to how to express this relationship in a clean way I would be very grateful.

Thanks

I have managed to figure out a solution.

The first main problem was a syntax error which stopped GORM from giving me any query logs. gorm:"references:Title,foreignKey:TableNo" json:"table" should have been gorm:"references:Title;foreignKey:TableNo" json:"table"

Next I changed the relationship to venueId as thinking back to the SQL this is what the join operation was being made on so we have gorm:"foreignKey:VenueId;references:VenueId" json:"table"

Finally the preload had to have a condition included to match the table number value:

r.db.Preload("Table", "replace(`table`.title, 'Table #', '') = ?", &order.TableNo).First(&order, id)

Now the question is how to not use replace and do this in a way where strings apart from 'Table #' can be in front of tableNo.

Hope someone finds this useful!