v10 Bulk Insert With OnConflict Removes Elements From Passed Slice

[Perplex]

When bulk inserting a slice, with OnConflict("DO NOTHING"), and some or all elements already exist in the DB. The resulting slice after the bulk insert is missing elements.

Expected Behavior

Slice contains same number of elements before and after bulk insert.

Current Behavior

Slice contains less elements after bulk insert.

Steps to Reproduce

type model struct {
  ID int
}

// Assume model-2 already exists in DB
models = []*model{
  {
    ID: 1,
  },
  {
    ID: 2,
  }
}

//  slice contain's two elements at this point

if _, err := db.Model(&models).OnConflict("DO NOTHING").Insert(); err != nil {
  ....
}

// slice contain's only one element, model-1

Context (Environment)

• go-pg V10
• Windows 10

[vmihailenco]

You need to add Returning("NULL") if you don't want to scan returned rows.

[Perplex]

This will return all the elements back but now IDs aren't populated in the slice. Im guessing there isn't a way to have both?

[vmihailenco]

Nope, except you could save the original slice and merge it with the result returned from db.

[Perplex]

Decided to just fetch the all inserted rows in a follow up query, thankfully its a small set.