Dynamodb.ScanInput - Cannot use 'expr.Names()' (type map[string]*string) as the type map[string]string

Question

I need to scan my table in dynamodb using filtering. I found many examples in internet but when I try use them I have the same error all the time.

filter := expression.Name("CreatedDate").LessThan(expression.Value(time.Now().UTC()))
expr, err := expression.NewBuilder().WithFilter(filter).Build()
if err != nil {
    panic(err)
}
out, err := svc.Scan(context.TODO(), &dynamodb.ScanInput{
    TableName:                 aws.String(tableName),
    FilterExpression:          expr.Filter(),
    ExpressionAttributeNames:  expr.Names(),
    ExpressionAttributeValues: expr.Values(),
})
if err != nil {
    panic(err)
}

On expr.Names() and expr.Values() I got error

Cannot use 'expr.Names()' (type map[string]*string) as the type map[string]string

Thank you in advance!

score 4 · Accepted Answer · answered Apr 18 '22 at 20:40

You did not specify if it was a compilation error or it is shown in the panic.

Anway, the expr.Names() expr.Values() would be map[string]*string in case of usage expression from aws-sdk-go except aws-sdk-go-v2.

Fix

Update your imports from

"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/config"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go/service/dynamodb/expression"

to something like below

"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/config"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"

Thanks. They moved expression from service to feature... That's why I didn't see that and used v1. — BElluu, Apr 19 '22 at 06:09

Dynamodb.ScanInput - Cannot use 'expr.Names()' (type map[string]*string) as the type map[string]string

1 Answers1

Fix