mysql - 如何在react js中从mysql中的表中呈现正确的日期

Question

我有点卡住了，我在 MySQL 中有一个表，其中有 4 个读数，日期字段中的日期不同，当我渲染它们时，它们都显示今天的日期...为什么？我做错了什么？这是我的代码...

getReading = user_id => { const { 读数 } = this.state;

if (
  readings.length > 0 &&
  readings.find(reading => reading.user_id === user_id)
) {
  this.setState({
    reading: {
      ...this.state.reading,
      user_id: readings.find(reading => reading.user_id === user_id)
        .user_id,
      date: readings.find(reading => reading.user_id === user_id).date,
      sugarB: readings.find(reading => reading.user_id === user_id).sugarB,
      carbsB: readings.find(reading => reading.user_id === user_id).carbsB,
      insulinB: readings.find(reading => reading.user_id === user_id)
        .insulinB,
      insulinSB: readings.find(reading => reading.user_id === user_id)
        .insulinSB,
      insulinFB: readings.find(reading => reading.user_id === user_id)
        .insulinFB,
      sugarL: readings.find(reading => reading.user_id === user_id).sugarL,
      carbsL: readings.find(reading => reading.user_id === user_id).carbsL,
      insulinL: readings.find(reading => reading.user_id === user_id)
        .insulinL,
      hbp: readings.find(reading => reading.user_id === user_id).hbp,
      lbp: readings.find(reading => reading.user_id === user_id).lbp,
      hr: readings.find(reading => reading.user_id === user_id).hr,
      sugarD: readings.find(reading => reading.user_id === user_id).sugarD,
      carbsD: readings.find(reading => reading.user_id === user_id).carbsD,
      insulinD: readings.find(reading => reading.user_id === user_id)
        .insulinD
    }
  });
}

}；我的状态看起来像这样...... 读数:[]， 阅读: { 用户 ID: 0, 日期:new Date().toLocaleDateString(), 糖B:0， 碳水化合物B: 0, 胰岛素B: 0, 胰岛素SB: 0, 胰岛素FB:0， 糖L:0， 碳水化合物L: 0, 胰岛素L: 0, 热结合蛋白: 0, 磅数:0， 小时:0， 糖D:0， 碳水化合物D: 0, 胰岛素D:0 },

Answer 1

您可以将代码更新为此代码，它将执行完全相同的操作，但更易于阅读。 SQL 中的日期可能为空。在渲染函数中，您可能会执行类似 new Date("from SQL"=> null) 的操作。

const currentReading = readings.find(reading => reading.user_id === user_id);
if (
  readings.length &&
  currentReading
) {
  this.setState({
    reading: {
      ...this.state.reading,
      ...currentReading
    }
  });
}