If I remove the "WHERE" part, it works fine (i.e. no exception generated when preparing the statement).

SELECT method FROM methodParameters AS mp INNER JOIN types ON mp.parameter = types.id GROUP BY method HAVING COUNT(method) >= ?

Peter Ondruška wrote:
Would you please try if there is any difference if you remove "name IN (?)".

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



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