Your Question

I have the following model:

type Test struct {
    ID int64 `gorm:"primaryKey"`
    Name string `gorm:"uniqueIndex"`
}

Now, if I want to make Name not unique anymore, the AutoMigrate func does not automatically remove the constraint. This is documented and fine.

My question is, how would I manually drop the unique constraint on the column, but keep the index?

The document you expected this should be explained

https://gorm.io/docs/migration.html

Expected answer

Code that drops the unique constraint

Comment From: a631807682

Currently only supports using DropIndex first and then CreateIndex.

DB.Migrator().DropIndex(&Test{},"idx_name")
DB.Migrator().CreateIndex(&Test{},"idx_name")