データベース - 経済統計練習帳

package dbx;
 
public class pro {
 
int creditnumber;
String[] credit=new String[50];
String[] style=new String[50];
int[] strlong=new int[50];
 
 
String[][] data=new String[5000][10];  
int datanumber;
int number;
int[] v=new int[500];
 
 
    public static void main(String[] args) {
        pro test=new pro();
    }
 
    pro(){
 
 
        creditnumber=2;
        credit[1]="a";
        credit[2]="b";
        style[1]="INTEGER";
        style[2]="VARCHAR";
        strlong[1]=0;
        strlong[2]=20;
 
        String db,tab;
 
        db="dbc";
        tab="dbc";
 
 
        table sub=new table();
        sub.credit=credit;
        sub.creditnumber=creditnumber;
        sub.style=style;
        sub.strlong=strlong;
        sub.makedata(db,tab);
 
 
        int s;
 
 datanumber=400;
 
 
 
        for(s=1;s<401;s++){
        data[s][1]=""+s;
        data[s][2]="b"+s;
        }
 
 
        insert sub2=new insert();
        sub2.creditnumber=creditnumber;
        sub2.style=style;
        sub2.data=data;
        sub2.datanumber=datanumber;
        sub2.makedata(db,tab);
 
 
 
 
        select sub3=new select();
        sub3.makedata(db,tab,"b25");
        number=sub3.number;
        v=sub3.v;
 
        System.out.println(number);
            System.out.println(v[1]);
 
 
 
 
 
 
 
 
    }
 
 
 
 
}
 
 
 
package dbx;
 
 
import java.sql.*; 
 
public class table{
 
    Connection dbx;   
Statement stx;   
String sqx; 
ResultSet  rsx; 
int creditnumber;
String[] credit=new String[50];
String[] style=new String[50];
int[] strlong=new int[50];
 
 
 
 
    void makedata(String db,String tab){
 
 
 
        String str;
 
        str="";
        int s;
        for(s=1;s<creditnumber;s++){
        if(style[s].equals("INTEGER"))str=str+credit[s]+" "+style[s]+",";
        if(style[s].equals("VARCHAR"))str=str+credit[s]+" "+style[s]+"("+strlong[s]+"),";
        }
        s=creditnumber;
        if(style[s].equals("INTEGER"))str=str+credit[s]+" "+style[s];
        if(style[s].equals("VARCHAR"))str=str+credit[s]+" "+style[s]+"("+strlong[s]+")";
 
 
 
 
    String url = "jdbc:h2:"+db+";create=true";   
String usr = "";   
String pwd = ""; 
 
 
 try{
 Class.forName("org.h2.Driver");
 
dbx = DriverManager.getConnection(url, usr, pwd); 
 
 
      stx = dbx.createStatement();
 
      String sqx = "CREATE TABLE " +tab+"("+str+")"; 
 
 
      stx.executeUpdate(sqx);
 
 } catch (Exception ex) { ex.printStackTrace();} 
 
 
 
 
 
 
    }
}
 
 
 
 
package dbx;
 
import java.sql.*;
import java.io.*;
 
class insert {
 
    Connection dbx;   
Statement stx;   
String sqx; 
ResultSet  rsx; 
 
String[] style=new String[50];
int creditnumber;
  String[][] data=new String[5000][50];  
int datanumber;
 
int p;
 
    void makedata(String db,String tab) {
 
        String str;
 
        int s,sx;
 
        for(p=1;p<datanumber+1;p++){
 
 
       str="";
 
        for(sx=1;sx<creditnumber;sx++){
        if(style[sx].equals("VARCHAR"))str=str+change(data[p][sx])+",";
        if(style[sx].equals("INTEGER"))str=str+data[p][sx]+",";
        }
        sx=creditnumber;
        if(style[sx].equals("VARCHAR"))str=str+change(data[p][sx]);
        if(style[sx].equals("INTEGER"))str=str+data[p][sx];
 
    String url = "jdbc:h2:"+db+";create=true";   
String usr = "";   
String pwd = ""; 
 
 
 try{
 Class.forName("org.h2.Driver");
 
dbx = DriverManager.getConnection(url, usr, pwd); 
 
 
      stx = dbx.createStatement();
 
      String sql = "INSERT INTO "+tab+" VALUES("+str+")";
 
    int num = stx.executeUpdate(sql);
 
    stx.close();
 } catch (Exception ex) { ex.printStackTrace();} 
 
        }
 
 
  }
String change(String str){
String str1;
str1="'"+str+"'";
return str1;
}
}
 
 
 
package dbx;
 
import java.sql.*; 
 
class select{ 
 
Connection dbx;   
Statement stx;   
String sqx; 
ResultSet  rsx; 
 
int key; 
String word;
int sx,number;
int[] v=new int[500];
 
void makedata(String db,String tab,String word){ 
 
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();} 
 
sx=0;
try {   
stx = dbx.createStatement(); 
sqx="select * from "+tab+" WHERE b like "+change(word);   
rsx = stx.executeQuery(sqx); 
if (rsx != null) { 
while (rsx.next()) { 
sx=sx+1;
v[sx]= rsx.getInt("a");
 
 
} 
} 
 
number=sx;
 
rsx.close(); 
stx.close(); 
dbx.close(); 
 
} catch (Exception ex) {ex.printStackTrace();} 
 
 
 
 
} 
 
String change(String word){
String e;
e="'"+word+"'";
return e;    
}    
 
 
 
}