Sto provando a scrivere un piccolo programma che deve memorizzare e recuperare i valori dal database. Il database è relazionale dell'oggetto.Come trattare con VARRAY (Oracle 9i) in JDBC?
Here're il DDL dichiarazioni:
create or replace type Guy as object (name varchar(80), address varchar(80), dateOfBirth date)
create or replace type KnownLanguages as varray(10) of varchar(80)
create table Coders (person_ Guy, description clob, knownLanguages_ KnownLanguages)
E questo è il mio codice Java:
package adbms;
import java.sql.Clob;
import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import oracle.jdbc.OracleDriver;
import oracle.jdbc.driver.OraclePreparedStatement;
import oracle.jdbc.driver.OracleResultSet;
import oracle.sql.ARRAY;
import oracle.sql.ArrayDescriptor;
public class SimpleJdbcApplication {
public static final String DRIVER_TYPE = "thin";
public static final String HOST_NAME = "localhost";
public static final int PORT = 1521;
public static final String DATABASE_SID = "ralphdb";
public static final String USER_NAME = "scott";
public static final String PASSWORD = "tiger";
public static final String URL = String.format("jdbc:oracle:%s:@%s:%d:%s", DRIVER_TYPE, HOST_NAME, PORT, DATABASE_SID);
private static Connection connection;
private static Scanner read;
private static PreparedStatement insertStatement;
private static PreparedStatement deleteStatement;
private static PreparedStatement updateStatement;
private static PreparedStatement displayStatement;
static {
try {
System.out.println(URL);
read = new Scanner(System.in);
DriverManager.registerDriver(new OracleDriver());
connection = DriverManager.getConnection(URL, USER_NAME, PASSWORD);
insertStatement = connection.prepareStatement("insert into Coders values(Guy(?,?,?) , ? , ?)");
deleteStatement = connection.prepareStatement("delete from Coders where person_.name=?");
updateStatement = connection.prepareStatement("update Coders set person_.name=? where person_.name=?");
displayStatement = connection.prepareStatement("select * from Coders");
} catch (Exception x) {
x.printStackTrace();
}
}
public static void main(String... args) throws SQLException {
while (true) {
System.out.println("Enter your choice.");
System.out.println("1. Insert");
System.out.println("2. Delete");
System.out.println("2. Update");
System.out.println("4. Display");
System.out.println("5. Enter a direct query");
System.out.println("6. Exit");
switch (read.nextInt()) {
case 1:
insertCoder();
break;
case 2:
removeCoder();
break;
case 3:
updateCoder();
break;
case 4:
displayAllCoders();
break;
case 5:
processDirectQuerry();
break;
default:
System.exit(0);
}
}
}
private static void processDirectQuerry() throws SQLException {
System.out.println("Enter the query.");
String query = read.nextLine();
connection.createStatement().execute(query);
}
private static void displayAllCoders() throws SQLException {
ResultSet resultSet = displayStatement.executeQuery();
System.out.println("Name\tAddress\tDate of birth\tDescription\tKnown Languages");
while (resultSet.next()) {
System.out.print(resultSet.getString("person_.name")+"\t");
System.out.print(resultSet.getString("person_.address")+"\t");
System.out.print(resultSet.getDate("person_.dateOfBirth")+"\t");
Clob description = resultSet.getClob("description");
System.out.print(description.getSubString(1L, (int) description.length()));
ARRAY oraArray = ((OracleResultSet) resultSet).getARRAY("knownLanguages_");
String[] languagesArray = (String[]) oraArray.getArray();
for (String language : languagesArray) {
System.out.print(language + " ");
}
System.out.println();
}
}
private static void updateCoder() throws SQLException {
System.out.println("Enter the name of the coder whose name is to be updated.");
String originalName = read.nextLine();
System.out.println("ENter the new name.");
String newName = read.nextLine();
updateStatement.setString(1, newName);
updateStatement.setString(2, originalName);
updateStatement.executeUpdate();
}
private static void removeCoder() throws SQLException {
System.out.println("Enter the name of coder to be removed.");
String name = read.nextLine();
deleteStatement.setString(1, name);
deleteStatement.executeUpdate();
}
private static void insertCoder() throws SQLException {
read = new Scanner(System.in);
System.out.println("Enter the name, address and date of birth.");
String name = read.nextLine();
String address = read.nextLine();
String dateOfBirth = read.nextLine();
System.out.println("Enter a brief description.");
String description = read.nextLine();
List<String> languagesList = new ArrayList<String>();
System.out.println("Enter names of known languages. (At most 10.) Type 'done' when you're done.");
String token = null;
int i = 0;
while (i < 10 && !(token = read.nextLine()).equalsIgnoreCase("done")) {
languagesList.add(token);
i++;
}
insertStatement.setString(1, name);
insertStatement.setString(2, address);
insertStatement.setDate(3, Date.valueOf(dateOfBirth));
insertStatement.setString(4, description);
//String[] languagesArray = (String[]) languagesList.toArray();
Object[] languagesArray = languagesList.toArray();
ArrayDescriptor arrayDescriptor = ArrayDescriptor.createDescriptor("KnownLanguages", connection);
ARRAY oraArray = new ARRAY(arrayDescriptor, connection, languagesArray);
((OraclePreparedStatement) insertStatement).setARRAY(5, oraArray);
insertStatement.executeUpdate();
}
}
Il codice compila bene. Ma quando provo ad inserire i valori nel database, si dà il seguente errore
F: \ adb> java SimpleJdbcApplication jdbc: oracle: thin: @ 127.0.0.1: 1521: ralphdb Inserire la vostra scelta. 1. Inserire 2. Eliminare 2. Aggiornamento 4. Visualizzare 5. Immettere una query diretta 6. Uscita 1 Immettere il nome, l'indirizzo e la data di nascita. rahul mumbai 1989-12-22 Inserire una breve descrizione. happy Immettere nomi di lingue conosciute. (Al massimo 10.) Digitare 'done' quando hai finito. C++ c java fatta eccezione nel thread "main" java.sql.SQLException: nome non valido modello: SYSTEM.K nownLanguages a oracle.jdbc.driver.DatabaseError.throwSqlException (DatabaseError.java : 112) a oracle.jdbc .driver.DatabaseError.throwSqlException (DatabaseError.java : 146) a oracle.jdbc.oracore.OracleTypeADT.initMetadata (OracleTypeADT.java:463 ) a oracle.jdbc.oracore.OracleTypeADT.init (OracleTypeADT.java:362 in oracle.sql.ArrayDescriptor.initPickler (ArrayDescriptor.java:1756) in oracle.sql.ArrayDescriptor. (ArrayDescriptor.java:272) in oracle.sql.ArrayDescriptor.createDescriptor (ArrayDescriptor.jav un: 196) a oracle.sql.ArrayDescriptor.createDescriptor (ArrayDescriptor.java:165) a oracle.sql.ArrayDescriptor.createDescriptor (ArrayDescriptor.java:150) a oracle.sql.ArrayDescriptor.createDescriptor (ArrayDescriptor.java: 115) a SimpleJdbcApplication.insertCoder (SimpleJdbcApplication.java:143) a SimpleJdbcApplication.main (SimpleJdbcApplication.java:62) F: \ adb>
Penso che ci sia qualcosa di sbagliato nel modo in cui ho gestito la VARRAY. Per favore aiutami ...
Grazie! :-)