在Java编程中，如何使用JDBC连接检索表的数据内容？假定数据库名称是：testdb，其中有一个表:employee，这个表中有4条记录。
创建数据库表的语句 -
use testdb;
create table if not exists employees (
id int not null,
age int not null,
first varchar (255),
last varchar (255)
);
INSERT INTO Employees VALUES (100, 28, 'Max', 'Su');
INSERT INTO Employees VALUES (101, 25, 'Wei', 'Wang');
INSERT INTO Employees VALUES (102, 30, 'Kida', 'Su');
INSERT INTO Employees VALUES (103, 28, 'Kobe', 'Bryant');
以下示例使用getString()，getInt()以及executeQuery()方法来获取和显示表的数据内容。
package com.yiibai;
import java.sql.*;
public class RetrieveTableContents {
public static void main(String[] args) {
String JDBC_DRIVER = "com.mysql.jdbc.Driver";
String DB_URL = "jdbc:mysql://localhost/testdb?useSSL=false";
String User = "root";
String Passwd = "123456";
try {
Class.forName(JDBC_DRIVER);
} catch (ClassNotFoundException e) {
System.out.println("Class not found " + e);
}
try {
Connection con = DriverManager.getConnection(DB_URL, User, Passwd);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM employees");
System.out.println("id name age");
System.out.println("===========================");
while (rs.next()) {
int id = rs.getInt("id");
String first_name = rs.getString("first");
String last_name = rs.getString("last");
String age = rs.getString("age");
System.out.println(id + " " + first_name + " " + last_name + " " + age);
}
} catch (SQLException e) {
System.out.println("SQL exception occured" + e);
}
}
}
上述代码示例将产生以下结果。
id name age
===========================
100 Max Su 28
101 Wei Wang 25
102 Kida Su 30
103 Kobe Bryant 28
注：如果JDBC驱动程序安装不正确，将获得
ClassNotfound异常。
Class not found java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
JDBC Class found
SQL exception occuredjava.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/testdb
