數據庫連接錯誤JDBC

Question

我正在使用Oracle Express Edition在JAVA/SQL中使用項目。該代碼有沒有編譯錯誤，但是當我嘗試運行它，我得到一個錯誤，指出：

失敗call.XE.SYS.DBMS_FEATURE_TEST_PROC_1

這裏是我的代碼：

import java.sql.*; 
import javax.sql.*; 

public class StudentAverages { 
public static void main(String[] args) { 

    try { 
     Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); 
     Connection con = DriverManager.getConnection("jdbc:oracle:driver_type:[username/password]@//host_name:port_number:SID"); 
     Statement st = con.createStatement(); 
     ResultSet rs = st.executeQuery("Select * from [Sheet1$]"); 

     ResultSetMetaData rsmd = rs.getMetaData(); 
     int numberOfColumns = rsmd.getColumnCount(); 


     while (rs.next()) { 

      for (int i = 1; i <= numberOfColumns; i++) { 
       if (i > 1) 
        System.out.print(", "); 
       String columnValue = rs.getString(i); 
       System.out.print(columnValue); 
      } 
      System.out.println(""); 
     } 

     st.close(); 
     con.close(); 

    } catch (Exception ex) { 
     System.err.print("Exception: "); 
     System.err.println(ex.getMessage()); 
    } 



} 
     public void StudentMean(Connection con, Statement st, ResultSet rs) throws SQLException{ 

       try{ 
     Statement stOne, stTwo, stThree, stFour; 
     String SelectAverage = "SELECT MEAN FROM STUDENTS"; 
      ResultSet rsOne = stOne.executeQuery(SelectAverage); 

    String TotalAverage = "SELECT Avg(MEAN) AS averages FROM STUDENTS"; 
      ResultSet rsTwo = stTwo.executeQuery(TotalAverage);  

      String student_stan_dev = "SELECT STDEV(MEAN) AS standardDeviation FROM STUDENTS"; 
      ResultSet rsThree = stThree.executeQuery(student_stan_dev); 

      int onesdMean = 1; 


      //Loop Duration_Sec column 
      while(rsOne.next()){ 

      //Convert values into float values 
      allAvgs = rsOne.getFloat("MEAN"); 
      totalAvg = rsTwo.getFloat("averages"); 
      StDev = rsThree.getFloat("standardDeviation"); 
      } 

        //Calculate one standard deviation away from mean 
        theSD = allAvgs - (onesdMean * StDev); 


         //Create a new column 
     String flaggedStudents = "ALTER TABLE STUDENTS ADD FlaggedStudents INT"; 
     ResultSet rsFour = stFour.executeUpdate(flaggedStudents); 

      if(allAvgs >= theSD){ 

          //Flag students who meet the criteria 
       String FlagHint = "INSERT INTO STUDENTS.FlaggedStudents VALUES('1')"; 
       st.executeUpdate(FlagHint); 
      } 

        //Count the students who meet the criteria and add those students 
        //to a new table 

     String countInstances = "SELECT STUDENTS.NAME, STUDENTS.FlaggedStudents" + 
       "COUNT(*)OVER(PARTITION BY STUDENTS) AS cnt FROM STUDENTS"; 
      st.executeQuery(countInstances); 


     st.executeUpdate("CREATE TABLE IF NOT EXISTS StudentCount" + 
     "(NAME INT , cnt INT)"); 

     String insertVals = String.format("INSERT INTO StudentCount" + 
       "(NAME , cnt INT") + 
       " VALUES ('%s','%s')"); 

     st.execute(insertVals); 
} 
    catch(SQLException e){ 
    e.printStackTrace(); 
    } 

}

什麼是造成這個錯誤，我怎樣才能讓我的項目運行？我正在使用瘦驅動程序。任何幫助，將不勝感激。

Stack Trace: 
    java.lang.ClassNotFoundException: oracle.jdbc.OracleDriver 
     at java.net.URLClassLoader$1.run(Unknown Source) 
     at java.net.URLClassLoader$1.run(Unknown Source) 
     at java.security.AccessController.doPrivileged(Native Method) 
     at java.net.URLClassLoader.findClass(Unknown Source) 
     at java.lang.ClassLoader.loadClass(Unknown Source) 
     at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) 
     at java.lang.ClassLoader.loadClass(Unknown Source) 
     at java.lang.Class.forName0(Native Method) 
     at java.lang.Class.forName(Unknown Source) 
     at StudentAverages.main(StudentAverages.java:23) 
exception : 
java.sql.SQLException: No suitable driver found for jdbc:oracle:driver_type:[username/password]@//host_name:port_number:SID 
     at java.sql.DriverManager.getConnection(Unknown Source) 
     at java.sql.DriverManager.getConnection(Unknown Source) 
     at StudentAverages.main(StudentAverages.java:31) 

Answer 1

ALTER TABLE將學生加入FlaggedStudents INT
CREATE TABLE IF NOT EXISTS StudentCount」 + 「（NAME INT，CNT INT）
INSERT INTO StudentCount」 +「（NAME，cnt INT」

上面的命令不會在Oracle上運行。 INT數據類型不受支持，IF NOT EXISTS子句是MySql語法。
首先正確的SQL命令，並檢查它們是否在像SQLDeveloper或Toad這樣的Oracle客戶端上工作，然後在您的java代碼中嘗試它們。

Answer 2

你應該嘗試這些步驟

1. 檢查Oracle驅動程序（ojdbc6.jar或ojdbc14.jar）文件是在你的項目中可用，當您使用的是Oracle 10g或11g classpath.You應該使用ojdb6.jar。

2. 改變這些線

   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); 
   

   到

   Class.forName("oracle.jdbc.driver.OracleDriver"); 
   

3. 而且還要檢查數據庫URL模式見參考文獻link。