HSQLDB: a tábla nem marad meg
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Üdv!
Elkezdtem egy hsqldb-s progit írni, de hamar belefutottam egy problémába. A program leteszteli, hogy létezik-e 2 tábla (egyszerűen futtat egy select-et). Ha nem, akkor létrehozza őket, és ismét teszteli (az utóbbit csak ideiglenesen). A probléma az, hogy indítás után megint nincs meg a tábla, de a második teszt mindig jelzi, hogy létrejött. Nem TEMP tábla, próbáltam MEMORY és CACHED módban is létrehozni, az sem segített rajta.
package test;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class Main {
Connection conn = null;
public Main() {
super();
}
public void run() {
try {
Runtime.getRuntime().addShutdownHook(new ShutdownThread());
Class.forName("org.hsqldb.jdbcDriver");
conn = DriverManager.getConnection("jdbc:hsqldb:file:./database.db", "sa", "");
conn.setAutoCommit(false);
System.out.println("Connection Succeeded, testing database...");
String[][] tests = new String[][] {
{ "currencies_sell", "SELECT curid, currency, time, value FROM currencies_sell;", // TOP 0 vagy LIMIT 0 esetén: Unexpected token: 0 in statement [0]
"CREATE MEMORY TABLE currencies_sell " +
"( curid INTEGER IDENTITY, currency CHAR(3), time DATETIME, value INTEGER );" },
{ "currencies_buy", "SELECT curid, currency, time, value FROM currencies_buy TOP 0;",
"CREATE CACHED TABLE currencies_buy " +
"( curid INTEGER IDENTITY, currency CHAR(3), time DATETIME, value INTEGER );" }
};
Statement stmt = null;
ResultSet rs = null;
for (int i = 0; i < tests.length; i++) {
try {
System.out.println("Testing table: " + tests[i][0]);
stmt = conn.createStatement();
rs = stmt.executeQuery(tests[i][1]);
System.out.println("OK");
} catch (SQLException e) {
System.out.println("Table not found: " + tests[i][0] + ". Creating...");
e.printStackTrace();
Statement create = null;
try {
create = conn.createStatement();
create.executeUpdate(tests[i][2]);
System.out.println(tests[i][2]);
System.out.println(tests[i][0] + " created.");
} catch (SQLException ex) {
System.out.println("Cannot create table. Exiting...");
return;
} finally {
if (create != null)
try {
create.close();
} catch (SQLException exx) {
}
}
} finally {
if (rs != null)
try {
stmt.close();
} catch (SQLException e) {
}
if (stmt != null)
try {
stmt.close();
} catch (SQLException e) {
}
}
}
for (int i = 0; i < tests.length; i++) {
try {
System.out.print("Testing table: " + tests[i][0] + ": ");
stmt = conn.createStatement();
rs = stmt.executeQuery(tests[i][1]);
System.out.println("OK");
} catch (SQLException e) {
System.out.println("Table not found: " + tests[i][0] + ". Exception: ");
e.printStackTrace();
} finally {
if (rs != null)
try {
stmt.close();
} catch (SQLException e) {
}
if (stmt != null)
try {
stmt.close();
} catch (SQLException e) {
}
}
}
System.out.println("DB check complete.");
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally {
}
}
public static void main(String[] args) {
new Main().run();
}
private class ShutdownThread extends Thread {
@Override
public void run() {
System.out.println("Shutting down...");
if (conn != null)
try {
conn.close();
System.out.println("Database connection closed");
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
Kimenet:
Connection Succeeded, testing database...
Testing table: currencies_sell
Table not found: currencies_sell. Creating...
java.sql.SQLException: Table not found in statement [SELECT curid, currency, time, value FROM currencies_sell]
at org.hsqldb.jdbc.Util.sqlException(Unknown Source)
at org.hsqldb.jdbc.jdbcStatement.fetchResult(Unknown Source)
at org.hsqldb.jdbc.jdbcStatement.executeQuery(Unknown Source)
at test.Main.run(Main.java:43)
at test.Main.main(Main.java:113)
CREATE MEMORY TABLE currencies_sell ( curid INTEGER IDENTITY, currency CHAR(3), time DATETIME, value INTEGER );
currencies_sell created.
Testing table: currencies_buy
Table not found: currencies_buy. Creating...
java.sql.SQLException: Table not found in statement [SELECT curid, currency, time, value FROM currencies_buy]
at org.hsqldb.jdbc.Util.sqlException(Unknown Source)
at org.hsqldb.jdbc.jdbcStatement.fetchResult(Unknown Source)
at org.hsqldb.jdbc.jdbcStatement.executeQuery(Unknown Source)
at test.Main.run(Main.java:43)
at test.Main.main(Main.java:113)
CREATE CACHED TABLE currencies_buy ( curid INTEGER IDENTITY, currency CHAR(3), time DATETIME, value INTEGER );
currencies_buy created.
Testing table: currencies_sell: OK
Testing table: currencies_buy: Table not found: currencies_buy. Exception:
DB check complete.
Shutting down...
Database connection closed
java.sql.SQLException: Unexpected token: 0 in statement [0]
at org.hsqldb.jdbc.Util.sqlException(Unknown Source)
at org.hsqldb.jdbc.jdbcStatement.fetchResult(Unknown Source)
at org.hsqldb.jdbc.jdbcStatement.executeQuery(Unknown Source)
at test.Main.run(Main.java:83)
at test.Main.main(Main.java:113)
Ami még érdekes, hogy TOP 0 sem tetszik neki, pedig elméletileg oda lehetne rakni. Viszont azt nem értem, hogy ez mért csak a második tesztnél okoz neki problémát. Ha syntax hiba, mért nem jelzi az elsőnél (ki sem írja az első hibaüzenetben a TOP-ot.
hsqldb.org-ról elérhető 1.8.0_10-es verziót használom.
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