It really seems like a bug.
I realized I have a similar query that I prepare. I modified my code so
that the second query uses the query generating an exception as a substring.
The two queries are:
private static final String
selectStr_simpleQueries_methodIdsHavingParameters =
"SELECT method" +
" FROM methodParameters AS mp" +
" INNER JOIN types ON mp.parameter = types.id" +
" WHERE types.name IN (%s)" +
" GROUP BY method" +
" HAVING COUNT(method) >= ?";
private static final String selectStr_complexQueries_methodsFromSignature =
"SELECT m.id AS methodId, isConstructor, isStatic, rT.name AS
result, cT.name AS class, m.name AS method, mp.position AS paramPos,
pT.name AS parameter" +
" FROM methods AS m" +
" INNER JOIN types AS cT ON m.class = cT.id" +
" INNER JOIN types AS rT ON m.returnType = rT.id" +
" LEFT OUTER JOIN methodParameters AS mp ON m.id = mp.method" +
" LEFT OUTER JOIN types AS pT ON mp.parameter = pT.id" +
" WHERE m.id IN (" +
" (" +
" SELECT m.id" +
" FROM methods AS m" +
" INNER JOIN types ON m.returnType = types.id" +
" WHERE types.name = ?"+
" )" +
" INTERSECT" +
" (" +
selectStr_simpleQueries_methodIdsHavingParameters +
" )" +
" )";
selectStr_simpleQueries_methodIdsHavingParameters is a substring of
selectStr_complexQueries_methodsFromSignature. They contain '%s' because
I reuse them multiple time, replacing the '%s ' by multiple '?'
For the first iteration, here are the strings I obtain:
SELECT method FROM methodParameters AS mp INNER JOIN types ON
mp.parameter = types.id WHERE types.name IN (?) GROUP BY method
HAVING COUNT(method) >= ?
SELECT m.id AS methodId, isConstructor, isStatic, rT.name AS result,
cT.name AS class, m.name AS method, mp.position AS paramPos, pT.name AS
parameter FROM methods AS m INNER JOIN types AS cT ON m.class =
cT.id INNER JOIN types AS rT ON m.returnType = rT.id LEFT
OUTER JOIN methodParameters AS mp ON m.id = mp.method LEFT
OUTER JOIN types AS pT ON mp.parameter = pT.id WHERE m.id IN (
( SELECT m.id FROM methods AS m
INNER JOIN types ON m.returnType = types.id WHERE types.name
= ? ) INTERSECT (SELECT method FROM
methodParameters AS mp INNER JOIN types ON mp.parameter =
types.id WHERE types.name IN (?) GROUP BY method HAVING COUNT(method)
>= ? ) )
sqlStr = new
String(selectStr_simpleQueries_methodIdsHavingParameters).replaceFirst("%s",
replStr);
System.out.println(sqlStr);
ps = dbConnection.prepareStatement(sqlStr);
Throws the NullPointer exception.
BUT:
sqlStr = new
String(selectStr_complexQueries_methodsFromSignature).replaceFirst("%s",
replStr);
System.out.println(sqlStr);
ps = dbConnection.prepareStatement(sqlStr);
Works fine.
Either "selectStr_simpleQueries_methodIdsHavingParameters" as a
substring of "selectStr_complexQueries_methodsFromSignature" is not
really prepared because of incompatibilities in
"selectStr_complexQueries_methodsFromSignature" or there is a bug.
2009/5/25, Gurvan Le Guernic <[email protected]>:
The NullPointer exception is thrown by the statement:
ps = dbConnection.prepareStatement(sqlStr);
,with ps a PreparedStatement ans sqlStr a string equal to
SELECT method, COUNT(method) FROM methodParameters INNER JOIN types
ON parameter = id WHERE name IN (?) GROUP BY method HAVING COUNT(method)
>= ?
I use similar code to prepare other statements and they work well. So I
guess that if there is an error in my code, it lies in the SQL select query.
Bryan Pendelton suggested filling a bug query. If I have no clue what
happens this evening, I' ll do it.
Peter Ondruška wrote:
Can we see how you set parameters for this prepared statement?
2009/5/25, Gurvan Le Guernic <[email protected]>:
Hi,
I have a java.lang.NullPointerException when preparing the following
statement:
SELECT method, COUNT(method) FROM methodParameters INNER JOIN types
ON parameter = id WHERE name IN (?) GROUP BY method HAVING COUNT(method)
>= ?
with the command: dbConnection.prepareStatement(sqlStr);
The tables involved are:
"CREATE TABLE types (" +
" id INT PRIMARY KEY GENERATED ALWAYS AS IDENTITY," +
" name VARCHAR(128) NOT NULL UNIQUE," +
" shortName VARCHAR(64) NOT NULL" +
")"
and
"CREATE TABLE methodParameters (" +
" method INT REFERENCES methods (id)," +
" position INT," +
" parameter INT REFERENCES types (id)" +
")"
SQL information for the exception are:
SQL state: XJ001
Error code: 0
And the stack trace is:
Message: Exception Java : ': java.lang.NullPointerException'.
java.sql.SQLException: Exception Java : ':
java.lang.NullPointerException'.
at
org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown
Source)
at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown
Source)
at org.apache.derby.impl.jdbc.Util.javaException(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.EmbedPreparedStatement.<init>(Unknown Source)
at
org.apache.derby.impl.jdbc.EmbedPreparedStatement20.<init>(Unknown
Source)
at
org.apache.derby.impl.jdbc.EmbedPreparedStatement30.<init>(Unknown
Source)
at
org.apache.derby.impl.jdbc.EmbedPreparedStatement40.<init>(Unknown
Source)
at
org.apache.derby.jdbc.Driver40.newEmbedPreparedStatement(Unknown Source)
at
org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown
Source)
at
org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown
Source)
at org.thinkcollabs.jmbrowser.db.DAO.initSelect(DAO.java:370)
at
org.thinkcollabs.jmbrowser.db.DB_Derby$MethodDataLoader.run(DB_Derby.java:254)
Caused by: java.sql.SQLException: Exception Java : ':
java.lang.NullPointerException'.
at
org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown
Source)
at
org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown
Source)
... 16 more
Caused by: java.lang.NullPointerException
at
org.apache.derby.impl.sql.compile.ColumnReference.remapColumnReferencesToExpressions(Unknown
Source)
at
org.apache.derby.impl.sql.compile.AggregateNode.getNewExpressionResultColumn(Unknown
Source)
at
org.apache.derby.impl.sql.compile.GroupByNode.addAggregateColumns(Unknown
Source)
at
org.apache.derby.impl.sql.compile.GroupByNode.addNewColumnsForAggregation(Unknown
Source)
at
org.apache.derby.impl.sql.compile.GroupByNode.addAggregates(Unknown
Source)
at org.apache.derby.impl.sql.compile.GroupByNode.init(Unknown
Source)
at org.apache.derby.iapi.sql.compile.NodeFactory.getNode(Unknown
Source)
at
org.apache.derby.impl.sql.compile.SelectNode.genProjectRestrict(Unknown
Source)
at
org.apache.derby.impl.sql.compile.SelectNode.modifyAccessPaths(Unknown
Source)
at
org.apache.derby.impl.sql.compile.DMLStatementNode.optimizeStatement(Unknown
Source)
at
org.apache.derby.impl.sql.compile.CursorNode.optimizeStatement(Unknown
Source)
at org.apache.derby.impl.sql.GenericStatement.prepMinion(Unknown
Source)
at org.apache.derby.impl.sql.GenericStatement.prepare(Unknown
Source)
at
org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext.prepareInternalStatement(Unknown
Source)
... 9 more
I can't see what I am doing wrong, but I am not an SQL expert. So, I am
doing something wrong or is there a problem with Derby 10.5.1.1?
Thank you,
Gurvan
