我正在尝试在我的 React 项目中对 Dynamo 数据库执行列表查询，但我一直收到以下错误

TypeError: patients is undefined
render
C:/Health Project/nutzer-system/src/PatientComponents/listPatients.js:62

  59 | console.log(patients)
  60 | return (
  61 |     <div className={classes.root}>
> 62 |   <Grid container className={classes.root} spacing={16}>
     | ^  63 |   {patients.map( patient => (
  64 |          <Grid key={patient.id} patient>
  65 |              <Card className={classes.card}>

下面是我的一些代码

state = {
        patients: []
      }

      componentDidMount = () => {
        this.getPatients()
      }

      getPatients = () => {
        API.graphql(graphqlOperation(queries.listPatients))
        .then(data => this.setState({patients: data.data.listPatients.patients}))
      };

  render(){
    const { classes } = this.props; 
    const { patients } = this.state;
    console.log(patients)
    return (
        <div className={classes.root}>
      <Grid container className={classes.root} spacing={16}>
      {patients.map( patient => (
             <Grid key={patient.id} patient>
                 <Card className={classes.card}>
                   <CardContent>
                   <Typography className={classes.title} color="textSecondary" gutterBottom>
                       {patient.Vorname}
                     </Typography>
                     <Typography component="p">
                       {patient.Nachname}
                     </Typography>
                     <Typography component="p">
                       {patient.Strasse}
                     </Typography>

如果您需要查看更多代码，只需说出来，我就会将其添加进去。我不知道如何解决这个问题。任何帮助解决这个问题的帮助都将不胜感激。谢谢！