データベースから値を保存および取得する必要がある小さなプログラムを作成しようとしています。データベースはオブジェクト リレーショナルです。
DDL ステートメントは次のとおりです。
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)
そして、これは私のJavaコードです:
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();
}
}
コードは正常にコンパイルされます。しかし、データベースに値を挿入しようとすると、次のエラーが発生します
F:\adb>java SimpleJdbcApplication jdbc:oracle:thin:@127.0.0.1:1521:ralphdb 選択肢を入力してください。1. 挿入 2. 削除 2. 更新 4. 表示 5. 直接クエリを入力 6. 終了 1 名前、住所、生年月日を入力します。rahul mumbai 1989-12-22 簡単な説明を入力してください。happy 既知の言語の名前を入力してください。(最大 10 個) 完了したら、「done」と入力します。c++ c java done スレッド「メイン」の例外 java.sql.SQLException: 無効な名前パターン: SYSTEM.K nownLanguages at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java :112) at oracle.jdbc.driver.DatabaseError. throwSqlException(DatabaseError.java :146) at oracle.jdbc.oracore.OracleTypeADT.initMetadata(OracleTypeADT.java:463) at oracle.jdbc.oracore.OracleTypeADT.init(OracleTypeADT.java:
VARRAY の処理方法に問題があると思います。私を助けてください...
ありがとうございました！:-)