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From Gabriele Kahlout <gabri...@mysimpatico.com>
Subject Re: cleaning database between test cases
Date Fri, 19 Mar 2010 15:28:55 GMT
Here is the code for wrapper methods that might be incorrect:

 public final static Connection connectToDerby(final File parentPath,
final boolean create) throws InstantiationException,
IllegalAccessException, ClassNotFoundException, SQLException {
        //  Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
        final Connection con =
DriverManager.getConnection("jdbc:derby:" + parentPath.getPath() +
File.separator + "db.sqlwrapper;create=" + create);
        return con;
    }

public static boolean shutDownDerby() {
        try {
            Connection con = connectToDerby();
            con.close();
            con =
DriverManager.getConnection("jdbc:derby:db.sqlwrapper;shutdown=true");

        } catch (SQLException e) { // with throw exception on
successful deletion.
            return true;
        }
        return false;
    }

2010/3/19, Gabriele Kahlout <gabriele@mysimpatico.com>:
> Here is the shortest test that shows the problem:
>
> import com.mysimpatico.sqlwrapper.*;
> import java.io.File;
> import java.sql.*;
>
> /*
>  * To change this template, choose Tools | Templates
>  * and open the template in the editor.
>  */
> /**
>  *
>  * @author simpatico
>  */
> public class DbDeletionTest {
>
>     public static boolean deleteDir(File dir) {
>         if (dir.isDirectory()) {
>             String[] children = dir.list();
>             for (int i = 0; i < children.length; i++) {
>                 boolean success = deleteDir(new File(dir, children[i]));
>                 if (!success) {
>                     return false;
>                 }
>             } // The directory is now empty so delete it return
> dir.delete(); }
>         }
>         return dir.delete();
>     }
>
>     public static void test() throws Exception {
>         final File dir = new File("test");
>         dir.mkdir();
>         final Connection con = SqlWrapper.connectToDerby(dir, true);
>         final Statement st = con.createStatement();
>         SqlWrapper.setVendor(SqlWrapper.vendor.JAVADB);
>
>         final String expTableName = "Expressions";
>         final String exp = "expression";
>         final ReferencedColumn expColumn = new ReferencedColumn(exp,
> SqlWrapper.VARCHAR, 100);
>         final Table expTable = new Table(expTableName, expColumn,
> expColumn);
>         st.executeUpdate(SqlWrapper.create(expTable));
>         con.close();
>         SqlWrapper.shutDownDerby();
>         deleteDir(dir);
>         System.out.println("test executed.");
>
>     }
>
>     public static void main(String[] args) {
>         try {
>             test();
>             test();
>         }
>             catch (Exception e) {
>             e.printStackTrace();
>         }
>     }
> }
> The libraries needed are: derby.jar, SqlWrapper.jar (just wraps around
> sql statements, u can replace it with sql strings).
> http://memorizeasy.googlecode.com/svn/tags/live/lib/derby.jar
> http://memorizeasy.googlecode.com/svn/tags/live/lib/sqlwrapper.jar
>
> The output is:
> test executed.
> Shutting down due to severe error.
> java.sql.SQLException: Table/View 'EXPRESSIONS' already exists in Schema
> 'APP'.
>         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.executeStatement(Unknown
> Source)
>         at org.apache.derby.impl.jdbc.EmbedStatement.execute(Unknown
> Source)
>         at org.apache.derby.impl.jdbc.EmbedStatement.executeUpdate(Unknown
> Source)
>         at DbDeletionTest.test(DbDeletionTest.java:42)
>         at DbDeletionTest.main(DbDeletionTest.java:53)
> Caused by: java.sql.SQLException: Table/View 'EXPRESSIONS' already
> exists in Schema 'APP'.
>         at
> org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown
> Source)
>         at
> org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown
> Source)
>
> 2010/3/19, Gabriele Kahlout <gabriele@mysimpatico.com>:
>> 'rm -R myDbDirectory' in *nix'
>> How do you programmatically, from java do that (OS independent)?
>> What I do is I iterate over the db folder and delete all contents, as
>> returned by the java.io API.
>>
>> However, even doing that seems not sufficient.
>> I see that the test folder (the one that contains db.sqlwrapper) is
>> deleted after the first test, and created in the setup of the next.
>> However, I get:
>>
>> Caused by: ERROR X0Y32: Table/View 'EXPRESSIONS' already exists in Schema
>> 'APP'.
>>
>> I think it has to do with the copy in memory not being updated with
>> the disk. That is because through the debugger, I've even manually
>> deleted the db, but to no avail.
>> Maybe this is more of a Java question now:
>> How do I make sure the memory is flushed/sync with the disk? Or that
>> derby, when creating a connection is not fooled by the cache in
>> memory?
>>
>>
>> 2010/3/19, Kristian Waagan <Kristian.Waagan@sun.com>:
>>> On 19.03.10 10:11, Gabriele Kahlout wrote:
>>>> Also, I've copied from the code what I seem to need, and then end up
>>>> with when I use the db again in a 2nd method.
>>>>
>>>> Caused by: java.sql.SQLException: Database '/Volumes/STORE N
>>>> GO/ws/MemorizEasy/test/db.sqlwrapper' not found.
>>>>
>>>> Note that after destroying the schemas, I shut down the db, and delete
>>>> the test folder of the previous method.
>>>>
>>>
>>> Hi Gabriele,
>>>
>>> I don't know the requirements of your application, but note that in
>>> general you have three options:
>>>
>>>   - clean the database and reuse it
>>>     This is what we're doing in the Derby test framework (see the class
>>> that Bryan pointed to), because it would take much longer to actually
>>> delete and recreate the database files all the time. Here we use
>>> meta-data to detect all objects added to the database during the test,
>>> and then we drop them.
>>>
>>>   - simply just delete the database on disk (i.e. 'rm -R myDbDirectory'
>>> in *nix) and create a new one for the next test (through JDBC, using
>>> 'jdbc:derby:...;create=true').
>>>     You should shut down the database before deleting the files on disk.
>>>
>>>   - if you just need a database for a short period of time or similar,
>>> use an in-memory db.
>>>     Remember to drop it [1] to free up the memory.
>>>
>>> It's hard to tell exactly what went wrong above, but are you sure the
>>> database is still on disk?
>>> Can you locate the directory? (you should see the directories
>>> db.sqlwrapper, db.sqlwrapper/seg0 and db.sqlwrapper/log)
>>> If not, why did it get deleted?
>>>
>>>
>>> --
>>> Kristian
>>>
>>> [1] Note that proper support for this is added in 10.6, by using the
>>> "drop=true" attribute. In 10.5, the mechanism is different.
>>>
>>>> 2010/3/18, Gabriele Kahlout<gabriele@mysimpatico.com>:
>>>>
>>>>> I reached here:
>>>>> http://svn.apache.org/viewvc/db/derby/code/trunk/java/testing/org/apache/derbyTesting/junit/CleanDatabaseTestSetup.java?view=markup
>>>>>
>>>>> But then what do I do? The code relies on some other class, and it
>>>>> seems like I'd have to import the whole package to use it. Is that it?
>>>>> Besides that one cannot delete the APP schema (which is the one i
>>>>> use), while the code seems to want to do that.
>>>>> If not, is there how I can use this without concerning myself with the
>>>>> impl. details?
>>>>>
>>>>> 2010/3/18, Gabriele Kahlout<gabriele@mysimpatico.com>:
>>>>>
>>>>>> Can you provide a link to it? Also, is it in some library I could
>>>>>> use?
>>>>>>
>>>>>> 2010/3/18, Bryan Pendleton<bpendleton.derby@gmail.com>:
>>>>>>
>>>>>>>> For testing, how can I make sure the tearDown completely
deletes
>>>>>>>> the
>>>>>>>> db, and setUp creates a completely new copy, without using
>>>>>>>> in-memory
>>>>>>>> db?
>>>>>>>>
>>>>>>> We do this in the Derby regression test suite.
>>>>>>>
>>>>>>> Have a look at
>>>>>>> org.apache.derbyTesting.functionTests.junit.CleanDatabaseTestSetup.java
>>>>>>>
>>>>>>> thanks,
>>>>>>>
>>>>>>> bryan
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> Regards,
>>>>>> K. Gabriele
>>>>>>
>>>>>> --- unchanged since 25/1/10 ---
>>>>>> P.S. Unless a notification (LON), please reply either with an answer
>>>>>> OR with " ACK" appended to this subject within 48 hours. Otherwise,
I
>>>>>> might resend.
>>>>>> In(LON, this) ∨ In(48h, TimeNow) ∨ ∃x. In(x, MyInbox) ∧ IsAnswerTo(x,
>>>>>> this) ∨ (In(subject(this), subject(x)) ∧ In(ACK, subject(x))
∧
>>>>>> ¬IsAnswerTo(x,this)) ⇒ ¬IResend(this).
>>>>>>
>>>>>> Also note that correspondence may be received only from specified
a
>>>>>> priori senders, or if the subject of this email ends with a code,
eg.
>>>>>> -LICHT01X, then also from senders whose reply contains it.
>>>>>> ∀x. In(x, MyInbox) ⇒ In(senderAddress(x), MySafeSenderList) ∨
(∃y.
>>>>>> In(y, subject(this) ) ∧ In(y,x) ∧ isCodeLike(y, -LICHT01X) ).
>>>>>>
>>>>>>
>>>>>
>>>>> --
>>>>> Regards,
>>>>> K. Gabriele
>>>>>
>>>>> --- unchanged since 25/1/10 ---
>>>>> P.S. Unless a notification (LON), please reply either with an answer
>>>>> OR with " ACK" appended to this subject within 48 hours. Otherwise, I
>>>>> might resend.
>>>>> In(LON, this) ∨ In(48h, TimeNow) ∨ ∃x. In(x, MyInbox) ∧ IsAnswerTo(x,
>>>>> this) ∨ (In(subject(this), subject(x)) ∧ In(ACK, subject(x)) ∧
>>>>> ¬IsAnswerTo(x,this)) ⇒ ¬IResend(this).
>>>>>
>>>>> Also note that correspondence may be received only from specified a
>>>>> priori senders, or if the subject of this email ends with a code, eg.
>>>>> -LICHT01X, then also from senders whose reply contains it.
>>>>> ∀x. In(x, MyInbox) ⇒ In(senderAddress(x), MySafeSenderList) ∨ (∃y.
>>>>> In(y, subject(this) ) ∧ In(y,x) ∧ isCodeLike(y, -LICHT01X) ).
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>> --
>> Regards,
>> K. Gabriele
>>
>> --- unchanged since 25/1/10 ---
>> P.S. Unless a notification (LON), please reply either with an answer
>> OR with " ACK" appended to this subject within 48 hours. Otherwise, I
>> might resend.
>> In(LON, this) ∨ In(48h, TimeNow) ∨ ∃x. In(x, MyInbox) ∧ IsAnswerTo(x,
>> this) ∨ (In(subject(this), subject(x)) ∧ In(ACK, subject(x)) ∧
>> ¬IsAnswerTo(x,this)) ⇒ ¬IResend(this).
>>
>> Also note that correspondence may be received only from specified a
>> priori senders, or if the subject of this email ends with a code, eg.
>> -LICHT01X, then also from senders whose reply contains it.
>> ∀x. In(x, MyInbox) ⇒ In(senderAddress(x), MySafeSenderList) ∨ (∃y.
>> In(y, subject(this) ) ∧ In(y,x) ∧ isCodeLike(y, -LICHT01X) ).
>>
>
>
> --
> Regards,
> K. Gabriele
>
> --- unchanged since 25/1/10 ---
> P.S. Unless a notification (LON), please reply either with an answer
> OR with " ACK" appended to this subject within 48 hours. Otherwise, I
> might resend.
> In(LON, this) ∨ In(48h, TimeNow) ∨ ∃x. In(x, MyInbox) ∧ IsAnswerTo(x,
> this) ∨ (In(subject(this), subject(x)) ∧ In(ACK, subject(x)) ∧
> ¬IsAnswerTo(x,this)) ⇒ ¬IResend(this).
>
> Also note that correspondence may be received only from specified a
> priori senders, or if the subject of this email ends with a code, eg.
> -LICHT01X, then also from senders whose reply contains it.
> ∀x. In(x, MyInbox) ⇒ In(senderAddress(x), MySafeSenderList) ∨ (∃y.
> In(y, subject(this) ) ∧ In(y,x) ∧ isCodeLike(y, -LICHT01X) ).
>


-- 
Regards,
K. Gabriele

--- unchanged since 25/1/10 ---
P.S. Unless a notification (LON), please reply either with an answer
OR with " ACK" appended to this subject within 48 hours. Otherwise, I
might resend.
In(LON, this) ∨ In(48h, TimeNow) ∨ ∃x. In(x, MyInbox) ∧ IsAnswerTo(x,
this) ∨ (In(subject(this), subject(x)) ∧ In(ACK, subject(x)) ∧
¬IsAnswerTo(x,this)) ⇒ ¬IResend(this).

Also note that correspondence may be received only from specified a
priori senders, or if the subject of this email ends with a code, eg.
-LICHT01X, then also from senders whose reply contains it.
∀x. In(x, MyInbox) ⇒ In(senderAddress(x), MySafeSenderList) ∨ (∃y.
In(y, subject(this) ) ∧ In(y,x) ∧ isCodeLike(y, -LICHT01X) ).

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