sql如何使用JDBC将列表或集合中的项目插入表中？

2024-04-24 04:16:04 118

要将数据库的内容插入到集合中，

连接到数据库，并使用SELECT查询将表的内容检索到ResultSet对象中。

DriverManager.registerDriver(new com.mysql.jdbc.Driver());
String mysqlUrl = "jdbc:mysql://localhost/mydatabase";
Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("select * from MyPlayers");

创建一个Java类来保存每个记录的内容，并为每个列（具有适当的数据类型）使用变量以及setter和getter方法。

例如，如果数据库中的表样本具有两个包含详细信息的字段，则：

列名：ID，数据类型：INT(11)

列名称：名称，数据类型VARCHAR(255)

然后，该类中的变量声明以及setter和getter方法将类似于-

import java.sql.Date;
public class Sample {
   private int ID;
   private String Name;
   public int getID() {
      return ID;
   }
   public void setID(int id) {
      ID = id;
   }
   public int getName() {
      return Name;
   }
   public void setName(int name) {
      Name = name;
   }
}

对于每个记录，创建上述类（示例）的对象，从ResultSet对象检索每一列的值，然后使用其setter方法将其设置为该对象，如-

Player player = new Player();
player.setID(rs.getInt("ID"));
player.setName(rs.getString("Name"));

将对象添加到所需的集合。

ArrayList<Player> arrayList = new ArrayList<>(); arrayList.add(player);

让我们使用CREATE语句在MySQL数据库中创建一个名为MyPlayers 的表，如下所示-

CREATE TABLE MyPlayers(
   ID INT,
   First_Name VARCHAR(255),
   Last_Name VARCHAR(255),
   Date_Of_Birth date,
   Place_Of_Birth VARCHAR(255),
   Country VARCHAR(255),
   PRIMARY KEY (ID)
);

现在，我们将使用INSERT语句在MyPlayers 表中插入7条记录-

insert into MyPlayers values(1, 'Shikhar', 'Dhawan', DATE('1981-12-05'), 'Delhi', 'India');
insert into MyPlayers values(2, 'Jonathan', 'Trott', DATE('1981-04-22'), 'CapeTown', 'SouthAfrica');
insert into MyPlayers values(3, 'Kumara', 'Sangakkara', DATE('1977-10-27'), 'Matale', 'Srilanka');
insert into MyPlayers values(4, 'Virat', 'Kohli', DATE('1988-11-05'), 'Delhi', 'India');
insert into MyPlayers values(5, 'Rohit', 'Sharma', DATE('1987-04-30'), 'Nagpur', 'India');
insert into MyPlayers values(6, 'Ravindra', 'Jadeja', DATE('1988-12-06'), 'Nagpur', 'India');
insert into MyPlayers values(7, 'James', 'Anderson', DATE('1982-06-30'), 'Burnley', 'England');

使用的Java类保存每个表的数据-

import java.sql.Date;
public class Player {
   private int ID;
   private String First_Name;
   private String Last_Name;
   private Date Date_Of_Birth;
   private String Place_Of_Birth;
   private String Country;
   public int getID() {
      return ID;
   }
   public void setID(int id) {
      ID = id;
   }
   public String getFirst_Name() {
      return First_Name;
   }
   public void setFirst_Name(String first_Name) {
      First_Name = first_Name;
   }
   public String getLast_Name() {
      return Last_Name;
   }
   public void setLast_Name(String last_Name) {
      Last_Name = last_Name;
   }
   public Date getDate_Of_Birth() {
      return Date_Of_Birth;
   }
   public void setDate_Of_Birth(Date date_Of_Birth) {
      Date_Of_Birth = date_Of_Birth;
   }
   public String getPlace_Of_Birth() {
      return Place_Of_Birth;
   }
   public void setPlace_Of_Birth(String place_Of_Birth) {
      Place_Of_Birth = place_Of_Birth;
   }
   public String getCountry() {
      return Country;
   }
   public void setCountry(String country) {
      Country = country;
   }
}

下面的JDBC程序检索MyPlayers表的内容，将它们添加到ArrayList中。

示例

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
public class TableToArrayList {
   public static void main(String args[]) throws Exception {
      //注册驱动程序
      DriverManager.registerDriver(new com.mysql.jdbc.Driver());
      //获得连接
      String mysqlUrl = "jdbc:mysql://localhost/mydatabase";
      Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
      System.out.println("Connection established......");
      //创建一个Statement对象
      Statement stmt = con.createStatement();
      //检索数据
      ResultSet rs = stmt.executeQuery("select * from MyPlayers");
      //创建一个ArrayList对象
      ArrayList<Player> arrayList = new ArrayList<>();
      //将表的记录添加到数组列表
      while(rs.next()) {
         Player player = new Player();
         player.setID(rs.getInt("ID"));
         player.setFirst_Name(rs.getString("First_Name"));
         player.setLast_Name(rs.getString("Last_Name"));
         player.setDate_Of_Birth(rs.getDate("Date_Of_Birth"));
         player.setPlace_Of_Birth(rs.getString("Place_Of_Birth"));
         player.setCountry(rs.getString("Country"));
         arrayList.add(player);
      }
      for (Player obj : arrayList) {
         System.out.print("ID: "+obj.getID()+", ");
         System.out.print("Name: "+obj.getFirst_Name()+", ");
         System.out.print("Age: "+obj.getLast_Name()+", ");
         System.out.print("Salary: "+obj.getDate_Of_Birth()+", ");
         System.out.print("Country: "+obj.getPlace_Of_Birth()+", ");
         System.out.print("Address: "+obj.getCountry());
         System.out.println();
      }
   }
}

输出结果

Connection established......
Records added to the array list.....
Contents of the array list:
ID: 1, Name: Shikhar, Age: Dhawan, Salary: 1981-12-05, Country: Delhi, Address: India
ID: 2, Name: Jonathan, Age: Trott, Salary: 1981-04-22, Country: CapeTown, Address: SouthAfrica
ID: 3, Name: Kumara, Age: Sangakkara, Salary: 1977-10-27, Country: Matale, Address: Srilanka
ID: 4, Name: Virat, Age: Kohli, Salary: 1988-11-05, Country: Mumbai, Address: India
ID: 5, Name: Rohit, Age: Sharma, Salary: 1987-04-30, Country: Nagpur, Address: India
ID: 6, Name: Ravindra, Age: Jadeja, Salary: 1988-12-06, Country: Nagpur, Address: India
ID: 7, Name: James, Age: Anderson, Salary: 1982-06-30, Country: Burnely, Address: England

sql如何使用JDBC将列表或集合中的项目插入表中？

示例

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