简单的JDBC连接数据库的例子

今天复习一下基础，弄个jdbc连接数据库的小例子。
1.建表

create table USERS  (
   USER_NAME            VARCHAR2(10)                    not null,
   COME_FROM            VARCHAR2(10),
   constraint PK_USERS primary key (USER_NAME)
);

2.插入数据

INSERT INTO USERS VALUES('张三','河北');
INSERT INTO USERS VALUES('李四','河南');
INSERT INTO USERS VALUES('王五','江苏');
INSERT INTO USERS VALUES('赵六','江西');
commit;

3.建立JDBC连接工具类

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class JdbcUtil {
	public static Connection getConnection() throws ClassNotFoundException, SQLException
	{
		Connection conn = null;
		Class.forName("oracle.jdbc.driver.OracleDriver");
		String url = "jdbc:oracle:thin:@localhost:1521:orcl";
		conn = DriverManager.getConnection(url, "sundful", "oracle");
		return conn;
	}
}

4.执行简单的查询

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class SimeSelectDemo {

	/**
	 * @param args
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception {
		Connection conn = null;
       try{	
	conn = JdbcUtil.getConnection();
         PreparedStatement ps = conn.prepareStatement("select * from users");
	ResultSet rs = ps.executeQuery();
		while (rs.next()) {
			StringBuffer buffer = new StringBuffer();
			buffer.append("用户名: ").append(rs.getString("user_name"));
			buffer.append("  籍贯: ").append(rs.getString("come_from"));
			System.out.println(buffer);
		}
}catch(SQLException e)
{
    e.printStackTrace();
}catch(Exception e)
{
    e.printStackTrace();
}finally{
    try {
		conn.close();
	} catch (SQLException e) {
		e.printStackTrace();
     }
   }
 }
}

这样就能够实现基本的jdbc连接数据库并执行相关的操作了。