JDBC嵌套while循环

Z时代
2024-01-10
分类：问答

那里。我是一个初学者使用java。我想为我的SQL查询结果做一个嵌套的while循环" title="while循环">while循环。JDBC嵌套while循环

我最初的结果就像下面，

eno ename title date_visit ssn pname charge 103 Jekyl Doctor 20170717 946883650 Gershwin 125 106 Ratchet Nurse 20170817 946883650 Gershwin 125 103 Jekyl Doctor 20170917 946883650 Gershwin 182 104 Caligari Doctor 20170707 831287780 Schubert 182 106 Ratchet Nurse 20170930 799023031 Haydn 190 102 Welby Doctor 20170818 416806352 Bernstein 210 102 Welby Doctor 20170808 874136439 Brahms 245 104 Caligari Doctor 20170808 796235486 Wagner 245 102 Welby Doctor 20170929 445139565 Chopin 405 102 Welby Doctor 20170910 874136439 Brahms 512 103 Jekyl Doctor 20170910 524246868 Verdi 512 103 Jekyl Doctor 20170909 129141378 Vivaldi 667 103 Jekyl Doctor 20170909 524246868 Verdi 667

，我写我的Java语句像下面，

//Now we execute our query and store the results in the myresults object:  
    ResultSet myresults1 = stmt1.executeQuery("SELECT DISTINCT eno, ename, title FROM Staff_Activity"); 
    ResultSet myresults2 = stmt2.executeQuery("SELECT eno, ename, title, date_visit, ssn, pname, SUM(charge) AS total_charge FROM Staff_Activity GROUP BY eno, ename, title, date_visit, ssn, pname"); 
    System.out.println("Employee_ID\tEmployee_Name\tTitle"); 
    System.out.println("-----------\t-------------\t------"); //Print a header 
    while (myresults1.next()) { //pass to the next row and loop until the last   
     System.out.println(myresults1.getInt("eno") + "\t\t" + myresults1.getString("ename") + "\t\t" + myresults1.getString("title")); 
     while (myresults2.next()) { 
      if (myresults1.getInt("eno")==(myresults2.getInt("eno"))) { 
       System.out.println(myresults2.getInt("date_visit") + "\t\t" + myresults2.getInt("ssn") + "\t\t" + myresults2.getString("pname") + "\t\t" + myresults2.getInt("total_charge")); 
      }//Print the current row 
     } 
     System.out.println(); 
    }

我只得到了结果我的表中只有一名工作人员，

Employee_ID Employee_Name Title ----------- ------------- ------ 103 Jekyl Doctor 20170909 524246868 Verdi 667 20170909 129141378 Vivaldi 667 20170910 524246868 Verdi 512 20170717 946883650 Gershwin 125 20170917 946883650 Gershwin 182 106 Ratchet Nurse 102 Welby Doctor 104 Caligari Doctor

真的想知道我的代码有什么问题。

在此先感谢。