如何在 Spring Boot 中将输入文本与数据库值进行比较？答案

【问题标题】：How to compare input text with database value in Spring Boot?如何在 Spring Boot 中将输入文本与数据库值进行比较？
【发布时间】：2020-01-06 01:47:00
【问题描述】：

我想做什么：在html中输入文本（例如：11:00:00）。然后将该输入值与数据库中的column Time进行比较，并显示与11:00:00相关的数据。我想我必须将输入文本从 Html 传输到 Controller，保存到一个变量中，然后在 Repository 文件中，我使用语法“Select ... from ... Where time = XXX”，但我不知道如何做...

我在 SQL server 中的表是 product，有 4 列：id、TAG00（我的温度数据）、Date，时间。

感谢您的帮助。

AppController.java

public class AppController {
@Autowired
private ProductService service; 
@Autowired
private ProductRepository prorepo;

@RequestMapping("/ChartBar")
public String viewBar(Model model) {
    List<Object[]> listData = service.listData(20);
    model.addAttribute("listData", listData);
    List<Object[]> listTime = service.listTime("20");
    model.addAttribute("listTime", listTime);
    return "ChartBar";
}
}

ProductRepository.java

public interface ProductRepository extends JpaRepository<Product, Long> {

@Query(value="SELECT tag00 FROM Product",nativeQuery =true)
public List<Object[]> findByTag00(@Param("tag00")float tag00);

@Query(value="SELECT time FROM Product",nativeQuery =true)
public List<Object[]> findByTime(@Param("time")String time);}

Product.java

@Entity
public class Product {
public int id;
public float tag00;
public String date;
public String time;
protected Product() {
}
protected Product(int id, float tag00, String date, String time) {
    super();
    this.id = id;
    this.tag00 = tag00;
    this.date = date;
    this.time = time;
}
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
public float getTAG00() {
    return tag00;
}
public void setTAG00(float tag00) {
    this.tag00 = tag00;
}
public String getDate() {
    return date;
}
public void setDate(String date) {
    this.date = date;
}   
public String getTime() {
    return time;
}
public void setTime(String time) {
    this.time = time;
}
}

ChartBar.html 我使用 Graph (ChartJS) 来显示数据库中的数据和时间。

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
   xmlns:th="http://www.thymeleaf.org">
<div  style="position:relative;left:50px;top:5px;"  > <!-- Position: 
relative(tuong quan theo left,right,bottom,top), absolute,fixed -->
  <a href="/">Home</a>       
</div> 
<script 
src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.8.0/Chart.min.js"> 
</script>
<link rel="stylesheet"href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<script src="https://cdn.jsdelivr.net/npm/chartjs-plugin-datalabels@0.5.0"> 
</script> <!-- thu vien dung de hien thi gia tri tren bieu do -->
<div class="container">
<canvas id="ChartBar"></canvas>
</div>
<div class="container">
<canvas id="myChart1" width ="350" height="350"></canvas>
</div>
<script th:inline="javascript">
let myChart1 = document.getElementById('myChart1').getContext('2d');
// Global Options
Chart.defaults.global.defaultFontFamily = 'Lato';
Chart.defaults.global.defaultFontSize = 18;
Chart.defaults.global.defaultFontColor = '#777';
let massPopChart = new Chart(myChart1, {
  type:'bar', // bar, horizontalBar, pie, line, doughnut, radar, polarArea
  data:{
    //labels: [1,3,5,7];
    labels:/*[[${listTime}]]*/,<!--my Time data-->
    datasets:[{
      label:'Temperature',      
      //data: [2,4,6,8];
      data:/*[[${listData}]]*/, <!--my Temperature data-->         
      backgroundColor:'rgba(255, 99, 132, 0.6)',              
      fill: false,
      borderWidth:1,
      borderColor:'rgba(255, 0, 0, 0.6)', //thay doi mau cho Line
      hoverBorderWidth:1,
      hoverBorderColor:'#111',
      pointRadius: 3
    }]
  },
  options: {      
      legend : {
          display: false,
      },
      responsive :  true ,
      maintainAspectRatio: false,         
      plugins: { //plugin dung de hien thi gia tri len bieu do
          datalabels: {
                display: function(context) {
                    return context.dataIndex % 1; 
                },
                backgroundColor: function(context) {
                    return context.dataset.backgroundColor;
                },
                backgroundColor: 'rgba(255, 255, 255,0)',
                borderRadius: 2,
                anchor : 'end',
                align : 'top',
                color: 'black',
                font: {
                    weight: 'bold'
                },
                formatter: Math.round
            }
        },
      scales: {//scales dung de cai dat option cho cot X,Y
          yAxes: [{
              ticks: {
                  beginAtZero: true,
                  stepSize: 0.1,
                  min: 24,
                  max: 25,
                  fontColor : 'blue'
              },
          }],
          xAxes: [{
              ticks: {
                  fontColor: 'blue'
              },
          }]
      }
  }
});

【问题讨论】：

标签： sql-server spring-boot spring-data-jpa chart.js thymeleaf

【解决方案1】：

试试

ProductRepository.java

public interface ProductRepository extends JpaRepository<Product, Long> {
    public List<Object[]> findByTag00Is(@Param("tag00")float tag00);
    public List<Object[]> findByTimeIs(@Param("time")float time2); 
}

findByTimeIs(float time2)这和Select ... from ... where time = time2一样

AppController.java

public class AppController {
    @Autowired
    private ProductService service; 
    @Autowired
    private ProductRepository prorepo;

    @RequestMapping("/ChartLine")
    public String viewLine(Model model, @RequestParam(name="time", required=false)float time) {
        // do anything with time
        // example : propero.findByTimeIs(time);
    }

【讨论】：

ChartLine.html 怎么样？我需要一个文本框来输入时间，然后将 html 中的时间与数据库中的时间进行比较...