JDBC对表的增添改查
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第一种写法:
public class Stu {
private int id;
private String name;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Stu(int id, String name) {
super();
this.id = id;
this.name = name;
}
public Stu(){}
}
import java.sql.SQLException;
import java.util.ArrayList;
public interface StuDeal {
public void insert(Stu stu) throws SQLException;
public void delete(int id)throws SQLException;
public void query(Stu stu)throws SQLException;
public ArrayList findCondition(Stu stu)throws SQLException;
}
/*
* 关闭各种资源的工具类
*
* **/
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.sql.ResultSet;
public class Util {
public static Connection getConnection(){
Connection conn=null;
try{
Class.forName("com.mysql.jdbc.Driver");
String url="jdbc:mysql://localhost:3306/test";
conn=DriverManager.getConnection(url,"root","1");}catch(Exception e){e.printStackTrace();}
return conn;
}
}
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
public class StuDao implements StuDeal{
public void insert(Stu stu) throws SQLException {
Connection conn = Util.getConnection();
PreparedStatement ps = conn
.prepareStatement("insert into stu values(?,?)");
ps.setInt(1, stu.getId());
ps.setString(2, stu.getName());
ps.executeUpdate();
}
public void delete(int id) throws SQLException {
Connection conn = Util.getConnection();
PreparedStatement ps = conn
.prepareStatement("delete from stu where id=?");
ps.setInt(1, id);
ps.executeUpdate();
}
public void query(Stu stu) throws SQLException {
Connection conn = Util.getConnection();
PreparedStatement ps = conn
.prepareStatement("select * from stu where id=?");
ps.setInt(1, stu.getId());
ResultSet rs = ps.executeQuery();
while (rs.next()) {
System.out.println("id号为:" + rs.getInt(1) + " " + "名字为:"
+ rs.getString(2));
}
sta.close();
rs.close();
conn.close();
}
public ArrayList findCondition(Stu stu)throws SQLException{
ArrayList <Stu>s=new ArrayList();
String sql="select id,name from stu where 1=1 and ";
if(stu.getId()!=0){
sql=sql+" id="+stu.getId()+" and ";
}
if(stu.getName()!=null){
sql=sql+" name ='"+stu.getName()+"' and";
}
if(sql.endsWith(" and")){
sql=sql.substring(0, sql.length()-3);
}
Connection conn = Util.getConnection();
Statement sta=conn.createStatement();
ResultSet rs=sta.executeQuery(sql);
while(rs.next()){
Stu st=new Stu();
st.setId(rs.getInt(1));
st.setName(rs.getString(2));
s.add(st);
}
sta.close();
rs.close();
conn.close();
return s;
}
}
import java.sql.SQLException;
import java.util.ArrayList;
public class StuTest {
/**
* @param args
* @throws SQLException
*/
public static void main(String[] args) th