我想创建一个使用java derby EmbeddedDriver的表，但我不明白这些错误是什么意思？

Question

错误：

run: 
Loaded the appropriate driver 
Created and connected to database localDB2 

----- SQLException ----- 
    SQL State: 42X01 
    Error Code: 30000 
    Message: Syntax error: Encountered "user" at line 1, column 14. 

___ DBTest completed ___ 
java.sql.SQLSyntaxErrorException: Syntax error: Encountered "user" at line 1, column 14. 
    at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source) 
    at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source) 
    at org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(Unknown Source) 
    at org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unknown Source) 
    at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown Source) 
    at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown Source) 
    at org.apache.derby.impl.jdbc.EmbedStatement.execute(Unknown Source) 
    at org.apache.derby.impl.jdbc.EmbedStatement.execute(Unknown Source) 
    at localDataBase.start(localDataBase.java:56) 
    at localDataBase.main(localDataBase.java:17) 
Caused by: java.sql.SQLException: Syntax error: Encountered "user" at line 1, column 14. 
    at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source) 
    at org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown Source) 
    ... 10 more 
Caused by: ERROR 42X01: Syntax error: Encountered "user" at line 1, column 14. 
    at org.apache.derby.iapi.error.StandardException.newException(Unknown Source) 
    at org.apache.derby.impl.sql.compile.ParserImpl.parseStatement(Unknown Source) 
    at org.apache.derby.impl.sql.GenericStatement.prepMinion(Unknown Source) 
    at org.apache.derby.impl.sql.GenericStatement.prepare(Unknown Source) 
    at org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext.prepareInternalStatement(Unknown Source) 
    ... 4 more 
BUILD SUCCESSFUL (total time: 0 seconds) 

代码：

import java.sql.*; 
import java.util.ArrayList; 
import java.util.Properties; 
import java.util.Date; 
import java.text.DateFormat; 
import java.text.SimpleDateFormat; 
import java.util.Calendar; 

public class localDataBase { 
    private String driver = "org.apache.derby.jdbc.EmbeddedDriver"; 
    private String protocol = "jdbc:derby:"; 
    private String dbName = "localDB2"; 
    private DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss"); 
    private Date date = new Date(); 
    private Calendar cal = Calendar.getInstance(); 
    public static void main(String[] args) { 
     new localDataBase().start(); 
     System.out.println("\n___ DBTest completed ___"); 
    } 

    void start() { 
    // Load derby driver to start derby engine 
    try { 
     Class.forName(driver); 
      System.out.println("Loaded the appropriate driver"); 
    } catch (ClassNotFoundException cnfe) { 
      System.err.println("\nUnable to load the JDBC driver " + driver); 
      System.err.println("Please check your CLASSPATH."); 
      cnfe.printStackTrace(System.err); 
     System.exit(1); 
     } 

    // establishing a connection to it 

    // Initializers; declared and set to nulls before the try-block 
    // to be accessible after the try-block scope 
    Connection conn = null; 
    PreparedStatement psInsertUser = null; 
     PreparedStatement psInsertAdmin = null; 
     PreparedStatement psInsertBill = null; 
    PreparedStatement psUpdate = null; 
    Statement stmt = null; 
    ResultSet rs = null; 

    try { 

     conn = DriverManager.getConnection(protocol + dbName + 
          ";create=true", "test", "test"); 

      System.out.println("Created and connected to database " + dbName); 

      stmt = conn.createStatement(); 


      // Create User table 
      stmt.execute("create table user(" + 
      "id int, " + 
      "firstName varchar(20), " + 
      "lastName varchar(20)" + 
         "userName varchar(20))"); 

      System.out.println("\n___ Created table user ___"); 

      // Create Administrator table 
      stmt.execute("create table administrator(" + 
      "id int, " + 
      "firstName varchar(20), " + 
      "lastName varchar(20)" + 
         "userName varchar(20))"); 

      System.out.println("\n___ Created administrator user ___"); 

      // Create Bill table 
      stmt.execute("create table bill(" + 
         "yearOfProduction int, " + 
      "serialNumber varchar(20), " + 
         "value int, " + 
      "location varchar(20)" + 
         "dateAndTimeCounted varchar(20))"); 

      System.out.println("\n___ Created table bill ___"); 

      //PreparedStatement to insert into User table 
      psInsertUser = conn.prepareStatement 
     ("insert into user values (?, ?, ?, ?)"); 

      // User1 Data 
      psInsertUser.setInt(1, 1); //insert ID 
     psInsertUser.setString(2, "Davy "); //insert firstName 
     psInsertUser.setString(3, "Jones"); //insert lastName 
      psInsertUser.setString(3, "User1"); //insert userName 
      psInsertUser.executeUpdate(); 

     System.out.println("\n ____ Inserted: User, Davy Jones"); 



      //PreparedStatement to insert into Administrator table 
      psInsertAdmin = conn.prepareStatement 
     ("insert into administrator values (?, ?, ?, ?)"); 

      // Admin1 Data 
      psInsertAdmin.setInt(1, 1); //insert ID 
     psInsertAdmin.setString(2, "Cutler "); //insert firstName 
     psInsertAdmin.setString(3, "Beckett"); //insert lastName 
      psInsertAdmin.setString(3, "Admin1"); //insert userName 
      psInsertAdmin.executeUpdate(); 

     System.out.println("\n ____ Inserted: Administrator, Cutler Beckett"); 


      //PreparedStatement to insert into Bill table 
      psInsertBill = conn.prepareStatement 
     ("insert into bill values (?, ?, ?, ?, ?)"); 

      // Bill1 Data 
      psInsertBill.setInt(1, 2011); //insert year of production 
     psInsertBill.setString(2, "XY3215616 "); //insert serial number 
     psInsertBill.setInt(3, 50); //insert value 
      psInsertBill.setString(4, "Jordan-Irbid-JUST-CairoAmmanBank"); //insert   Location 
      psInsertBill.setString(5, dateFormat.format(cal.getTime()).toString()); //insert date and time 
      psInsertBill.executeUpdate(); 

     System.out.println("\n ____ Inserted: Bill, XY3215616 50"); 



     //Show user table data 
     rs = stmt.executeQuery 
     ("SELECT * FROM user order by id"); 

     System.out.printf("\n\n%4s%20s%20s%20s\n", 
        "Id", "First Name", "Last Name", "User Name"); 
     while (rs.next()) 
     System.out.printf("%4d%20s%20s%20s\n", 
        rs.getInt("id"), 
        rs.getString("firstName"), 
            rs.getString("lastName"), 
            rs.getString("userName")); 

      //Show administrator table data 
     rs = stmt.executeQuery 
     ("SELECT * FROM administrator order by id"); 

     System.out.printf("\n\n%4s%20s%20s%20s\n", 
        "Id", "First Name", "Last Name", "User Name"); 
     while (rs.next()) 
     System.out.printf("%4d%20s%20s%20s\n", 
        rs.getInt("id"), 
        rs.getString("firstName"), 
            rs.getString("lastName"), 
            rs.getString("userName")); 

      //Show user bill data 
     rs = stmt.executeQuery 
     ("SELECT * FROM bill order by serialNumber"); 

     System.out.printf("\n\n%4s%20s%20s%20s\n", 
        "year Of Production", "Serial Number", "Value", "Location", "date and time"); 
     while (rs.next()) 
     System.out.printf("%4d%20s%20s%20s%20s\n", 
        rs.getInt("id"), 
        rs.getString("firstName"), 
            rs.getInt("value"), 
            rs.getString("location"), 
            rs.getString("dateAndTimeCounted")); 


     // Commit the transaction. Any changes will be persisted to the database now. 
      conn.commit(); 
      System.out.println("Committed the transaction"); 

     try { 
     // the shutdown=true attribute shuts down Derby 
     DriverManager.getConnection("jdbc:derby:;shutdown=true"); 
     System.out.println("Derby shut down normally"); 
     } 
     catch (SQLException se) { 
     System.err.println("Derby did not shut down normally"); 
     } 
    } 
    catch (SQLException sqle) { 
      printSQLException(sqle); 
     } finally { 
      // release all open resources to avoid unnecessary memory usage 
      // Connection 
      try { 
       if (conn != null) { 
        conn.close(); 
        conn = null; 
       } 
      } catch (SQLException sqle) { 
       printSQLException(sqle); 
      } 
     } 
    } // start() 

    public static void printSQLException(SQLException e) { 
    System.err.println("\n----- SQLException -----"); 
    System.err.println(" SQL State: " + e.getSQLState()); 
    System.err.println(" Error Code: " + e.getErrorCode()); 
    System.err.println(" Message: " + e.getMessage()); 
    // for stack traces, you may refer to derby.log 
    e.printStackTrace(System.err); 
    } 
} 

Answer 1

有这个代码许多错误。

1. 在创建表语句中忘记'，'。

2. 不能使用'user'，因为它是保留字。

3. 设置列20的长度，并尝试插入大于此值的数据。

4. 使用了表中不存在的错误列名。