データベース活用 - 経済統計練習帳

package mai;
 
 
public class pro {
 
    int number;
   String[] v=new String[70000];
   int[] year=new int[5000];
int[] month=new int[5000];
 
    public static void main(String[] args) {
        pro y=new pro();
    }
 
    pro(){
 
        select sub=new select();
        sub.makedata("mai","mai","c1","b1","w1","s1");
        number=sub.number;
v=sub.v;
year=sub.year;
month=sub.month;
 
int s;
for(s=1;s<number+1;s++){
  System.out.println(year[s]+"年"+month[s]+"月,"+v[s]);
    }
 
 
    }
 
 
}
 
package mai;
 
import java.sql.*; 
 
class select{ 
 
Connection dbx;   
Statement stx;   
String sqx; 
ResultSet  rsx; 
 
int key; 
String word;
int sx,number;
int[] year=new int[5000];
String[] v=new String[5000];
int[] month=new int[500];
 
void makedata(String db,String tab,String cx,String bx,String wx,String sx){ 
 
String url = "jdbc:h2:"+db+";create=true";   
String usr = "";   
String pwd = ""; 
 
 
 try
          {
            Class.forName("org.h2.Driver");
 
dbx = DriverManager.getConnection(url, usr, pwd); 
} catch (Exception ex) { ex.printStackTrace();} 
 
int s=0;
try {   
stx = dbx.createStatement(); 
sqx="select * from "+tab+" WHERE credit="+change(cx)+" and bus="+change(bx)+" and size="+change(sx)+" and work="+change(wx);   
rsx = stx.executeQuery(sqx); 
if (rsx != null) { 
while (rsx.next()) { 
s=s+1;
v[s]= rsx.getString("value");
year[s]=rsx.getInt("year");
month[s]=rsx.getInt("month");
} 
} 
 
number=s;
 
 
rsx.close(); 
stx.close(); 
dbx.close(); 
 
} catch (Exception ex) {ex.printStackTrace();} 
 
 
 
 
} 
 
String change(String word){
String e;
e="'"+word+"'";
return e;    
}    
 
 
 
}