Crud, I missed this comment somehow, I'll look at DERBY-934 again, I bet
*both* my questions will be answered :)
I'll get back to you if I need anything else, Andreas.
David
Andreas Korneliussen (JIRA) wrote:
[ http://issues.apache.org/jira/browse/DERBY-795?page=all ]
Andreas Korneliussen updated DERBY-795:
---------------------------------------
Attachment: DERBY-795.diff
DERBY-795.diff
Attached is a fix for this issue.
The problem is detected by the jdbcapi/SURQueryMix.junit test provided in
DERBY-934, when running in embedded mode.
After calling ResultSet.relative(0) the cursor loses its position
-----------------------------------------------------------------
Key: DERBY-795
URL: http://issues.apache.org/jira/browse/DERBY-795
Project: Derby
Type: Bug
Components: JDBC
Versions: 10.1.2.1
Environment: Any
Reporter: Andreas Korneliussen
Assignee: Andreas Korneliussen
Priority: Minor
Attachments: DERBY-795.diff, DERBY-795.diff
After calling rs.relative(0), on a scrollable ResultSet, the cursor looses its
position, and a rs.getXXX(..) fails with:
SQL Exception: Invalid cursor state - no current row.
Probably caused by the following logic in
ScrollInsensitiveResultSet.getRelativeRow(int row):
// Return the current row for 0
if (row == 0)
{
if ((beforeFirst || afterLast) ||
(!beforeFirst && !afterLast)) {
return null;
} else {
return getRowFromHashTable(currentPosition);
}
}
The if () will always evaluate to true, regardless of the values of beforeFirst
and afterLast
Test code:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class RelativeZeroIssue {
public static void main(String[] args) throws Exception {
Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
Connection con =
DriverManager.getConnection("jdbc:derby:testdb2;create=true");
con.setAutoCommit(false);
try {
Statement statement = con.createStatement();
/** Create the table */
statement.execute("create table t1(id int)");
statement.execute("insert into t1 values 1,2,3,4,5,6,7,8");
Statement s = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
ResultSet rs = s.executeQuery("select * from t1");
rs.next();
System.out.println(rs.getInt(1));
System.out.println(rs.relative(0));
System.out.println(rs.getInt(1));
} finally {
con.rollback();
con.close();
}
}
}
Output from test:
1
false
Exception in thread "main" SQL Exception: Invalid cursor state - no current row.
at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection.newSQLException(Unknown
Source)
at org.apache.derby.impl.jdbc.ConnectionChild.newSQLException(Unknown
Source)
at org.apache.derby.impl.jdbc.EmbedResultSet.checkOnRow(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedResultSet.getColumn(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedResultSet.getInt(Unknown Source)
at derbytest.RelativeZeroIssue.main(RelativeZeroIssue.java:51)
Java Result: 1
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fn:David W Van Couvering
n:Van Couvering;David W
org:Sun Microsystems, Inc.;Database Technology Group
email;internet:[EMAIL PROTECTED]
title:Senior Staff Software Engineer
tel;work:510-550-6819
tel;cell:510-684-7281
x-mozilla-html:TRUE
version:2.1
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