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graphql-golang nullable int field
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| //the idea is taken from https://gist.github.com/bosgood/d9687f5d64c0f4038bc19c478d51fa64 | |
| // but that code throw exception and does not compile | |
| // I just refined that and fix the problem and convert it to Int version | |
| // same can be done for other nullable types | |
| // LeadItem struct | |
| type LeadItem struct { | |
| CustomerId sql.NullInt64 | |
| } | |
| //the names of fields should 100% match struct field name | |
| var Lead = graphql.NewObject( | |
| graphql.ObjectConfig{ | |
| Name: "Lead", | |
| Fields: graphql.Fields{ | |
| "CustomerId": &graphql.Field{ | |
| Type: graphql.Int, | |
| Resolve: resolveNullableInt, | |
| }, | |
| }, | |
| }, | |
| ) | |
| func resolveNullableInt(p graphql.ResolveParams) (interface{}, error) { | |
| v := reflect.ValueOf(p.Source) | |
| if !v.IsValid() { | |
| return nil, fmt.Errorf("Invalid elem: %v", p.Source) | |
| } | |
| fieldName := p.Info.FieldName | |
| f := v.FieldByName(fieldName) | |
| if !f.IsValid() { | |
| return nil, fmt.Errorf("Missing field: %v", fieldName) | |
| } | |
| nullString := f.Interface().(sql.NullInt64) | |
| if nullString.Valid { | |
| return nullString.Int64, nil | |
| } | |
| return nil, nil | |
| } |
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