How I can store array of strings using gorm-spanner

[nahuelmonserrat]

Thanks for stopping by to ask us a question! Please make sure to include:

• What you're trying to do
  I'm trying to store a set of values in a column of type array string in Spanner using GORM, but I'm encountering an error.
• What code you've already tried

type NewEntity struct {
	Field1 int64            `gorm:"primaryKey;autoIncrement:false;column:picture_key"`
	Field2 []string        `gorm:"type:ARRAY<STRING(MAX)>;column:models"`
	Field3 time.Time   `gorm:"column:updated_at"`
}

dbEntity := model.NewEntity(p)
err := db.Create(dbEntity).Error
if err != nil {
  panic(err)
}

• Any error messages you're getting

spanner: code = \"InvalidArgument\", desc = \"Value has type STRUCT<STRING, STRING, STRING, ...> which cannot be inserted into column Field2, which has type ARRAY<STRING> [at 1:168]\\n...Field3`) VALUES (@p1,(@p2,@p3,@p4,@p5,@p6,@p7,@..

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[pdarulewski]

@nahuelmonserrat I think I have the same problem as yours but with floats.

spanner: code = "InvalidArgument", desc = "Value has type STRUCT<FLOAT64, FLOAT64> which cannot be inserted into column data, which has type ARRAY

What I've been doing to workaround this is to implement Valuer for my array types - it converts the []float64 to spanner.NullFloat64 type:

type Vector []float64

func (v Vector) Value() (driver.Value, error) {
	vector := make([]spanner.NullFloat64, 0, len(v))

	for _, f := range v {
		vector = append(vector, spanner.NullFloat64{Float64: f, Valid: true})
	}

	return vector, nil
}

type Entity struct {
	Data Vector `gorm:"not null;type:ARRAY<FLOAT64>""`
}

I think go-gorm-spanner should work with all array types, also with both []float64 and pq.Float64Array.

[pdarulewski]

Looks like it's not related to the gorm integration but the core library: googleapis/go-sql-spanner#331