func descToField()

in go/adbc/driver/snowflake/connection.go [592:675]
79 lines of code
23 McCabe index (conditional complexity)

func descToField(name, typ, isnull, primary string, comment sql.NullString) (field arrow.Field, err error) {
	field.Name = strings.ToLower(name)
	if isnull == "Y" {
		field.Nullable = true
	}
	md := make(map[string]string)
	md["DATA_TYPE"] = typ
	md["PRIMARY_KEY"] = primary
	if comment.Valid {
		md["COMMENT"] = comment.String
	}
	field.Metadata = arrow.MetadataFrom(md)

	paren := strings.Index(typ, "(")
	if paren == -1 {
		// types without params
		switch typ {
		case "FLOAT":
			fallthrough
		case "DOUBLE":
			field.Type = arrow.PrimitiveTypes.Float64
		case "DATE":
			field.Type = arrow.FixedWidthTypes.Date32
		// array, object and variant are all represented as strings by
		// snowflake's return
		case "ARRAY":
			fallthrough
		case "OBJECT":
			fallthrough
		case "VARIANT":
			field.Type = arrow.BinaryTypes.String
		case "GEOGRAPHY":
			fallthrough
		case "GEOMETRY":
			field.Type = arrow.BinaryTypes.String
		case "BOOLEAN":
			field.Type = arrow.FixedWidthTypes.Boolean
		default:
			err = adbc.Error{
				Msg:  fmt.Sprintf("Snowflake Data Type %s not implemented", typ),
				Code: adbc.StatusNotImplemented,
			}
		}
		return
	}

	prefix := typ[:paren]
	switch prefix {
	case "VARCHAR", "TEXT":
		field.Type = arrow.BinaryTypes.String
	case "BINARY", "VARBINARY":
		field.Type = arrow.BinaryTypes.Binary
	case "NUMBER":
		comma := strings.Index(typ, ",")
		scale, err := strconv.ParseInt(typ[comma+1:len(typ)-1], 10, 32)
		if err != nil {
			return field, adbc.Error{
				Msg:  "could not parse Scale from type '" + typ + "'",
				Code: adbc.StatusInvalidData,
			}
		}
		if scale == 0 {
			field.Type = arrow.PrimitiveTypes.Int64
		} else {
			field.Type = arrow.PrimitiveTypes.Float64
		}
	case "TIME":
		field.Type = arrow.FixedWidthTypes.Time64ns
	case "DATETIME":
		fallthrough
	case "TIMESTAMP", "TIMESTAMP_NTZ":
		field.Type = &arrow.TimestampType{Unit: arrow.Nanosecond}
	case "TIMESTAMP_LTZ":
		field.Type = &arrow.TimestampType{Unit: arrow.Nanosecond, TimeZone: loc.String()}
	case "TIMESTAMP_TZ":
		field.Type = arrow.FixedWidthTypes.Timestamp_ns
	default:
		err = adbc.Error{
			Msg:  fmt.Sprintf("Snowflake Data Type %s not implemented", typ),
			Code: adbc.StatusNotImplemented,
		}
	}
	return
}