发表于: 2017-06-28 21:13:16
2 1102
今天完成的事情:
1. JDBC的结果集初步了解
明天计划的事情:
暂时放下JDBC,明天开始MyBatis教程
遇到的问题:
ResultSet类型,具体的区别没有试出来
收获:
1. JDBC浏览结果集
//显示最后一个数据
rs.last();
//显示上一个数据
rs.previous();
//显示下一个数据
rs.next();
//显示第一个数据
rs.first();
代码
package NavigatingResultSet;
import java.sql.*;
public class NavigatingResultSet {
public static final String URL = "jdbc:mysql://localhost:3306/day"
+ "?useUnicode=true&characterEncoding=utf-8&useSSL=false";
public static final String USER = "root";
public static final String PASS = "qwe123";
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
try{
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(URL,USER,PASS);
//创建所需的ResultSet,向前,只读
stmt = conn.createStatement(
ResultSet.TYPE_FORWARD_ONLY,
ResultSet.CONCUR_READ_ONLY);
String sql;
sql = "SELECT id, name, study_type FROM day";
ResultSet rs = stmt.executeQuery(sql);
//显示最后一个数据
rs.last();
String id = rs.getString("id");
String name = rs.getString("name");
String study_type = rs.getString("study_type");
System.out.print("最后一条数据\nID: " + id);
System.out.print(", name: " + name);
System.out.println(", study_type: " + study_type);
//显示上一个数据
rs.previous();
id = rs.getString("id");
name = rs.getString("name");
study_type = rs.getString("study_type");
System.out.print("上一条数据\nID: " + id);
System.out.print(", name: " + name);
System.out.println(", study_type: " + study_type);
System.out.println("Moving cursor to the next row...");
//显示下一个数据
rs.next();
id = rs.getString("id");
name = rs.getString("name");
study_type = rs.getString("study_type");
System.out.print("下一条数据\nID: " + id);
System.out.print(", name: " + name);
System.out.println(", study_type: " + study_type);
//显示第一个数据
rs.first();
id = rs.getString("id");
name = rs.getString("name");
study_type = rs.getString("study_type");
System.out.print("第一条数据\nID: " + id);
System.out.print(", name: " + name);
System.out.println(", study_type: " + study_type);
rs.close();
stmt.close();
conn.close();
}catch(SQLException se){
se.printStackTrace();
}catch(Exception e){
e.printStackTrace();
}finally{
try{
if(stmt!=null)
stmt.close();
}catch(SQLException se2){
}
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}
}
System.out.println("Goodbye!");
}
}
参考资料
PS:暂时放下JDBC,东西太多,师兄说的对,先了解个框架吧
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