sql如何使用JDBC将列表或集合中的项目插入表中?
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
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