Examples with ExecutionContext org.datanucleus.ExecutionContext used on opensource projects

Example 56 with ExecutionContext

use of org.datanucleus.ExecutionContext in project datanucleus-rdbms by datanucleus.

the class AbstractArrayStore method set.

/**
 * Method to set the array for the specified owner to the passed value.
 * @param op ObjectProvider for the owner
 * @param array the array
 * @return Whether the array was updated successfully
 */
public boolean set(ObjectProvider op, Object array) {
    if (array == null || Array.getLength(array) == 0) {
        return true;
    }
    // Validate all elements for writing
    ExecutionContext ec = op.getExecutionContext();
    int length = Array.getLength(array);
    for (int i = 0; i < length; i++) {
        Object obj = Array.get(array, i);
        validateElementForWriting(ec, obj, null);
    }
    boolean modified = false;
    List exceptions = new ArrayList();
    boolean batched = allowsBatching() && length > 1;
    try {
        ManagedConnection mconn = storeMgr.getConnectionManager().getConnection(ec);
        try {
            processBatchedWrites(mconn);
            // Loop through all elements to be added
            E element = null;
            for (int i = 0; i < length; i++) {
                element = (E) Array.get(array, i);
                try {
                    // Add the row to the join table
                    int[] rc = internalAdd(op, element, mconn, batched, i, (i == length - 1));
                    if (rc != null) {
                        for (int j = 0; j < rc.length; j++) {
                            if (rc[j] > 0) {
                                // At least one record was inserted
                                modified = true;
                            }
                        }
                    }
                } catch (MappedDatastoreException mde) {
                    exceptions.add(mde);
                    NucleusLogger.DATASTORE.error("Exception thrown in set of element", mde);
                }
            }
        } finally {
            mconn.release();
        }
    } catch (MappedDatastoreException e) {
        exceptions.add(e);
        NucleusLogger.DATASTORE.error("Exception thrown in set of element", e);
    }
    if (!exceptions.isEmpty()) {
        // Throw all exceptions received as the cause of a NucleusDataStoreException so the user can see which
        // record(s) didn't persist
        String msg = Localiser.msg("056009", ((Exception) exceptions.get(0)).getMessage());
        NucleusLogger.DATASTORE.error(msg);
        throw new NucleusDataStoreException(msg, (Throwable[]) exceptions.toArray(new Throwable[exceptions.size()]), op.getObject());
    }
    return modified;
}

Example 57 with ExecutionContext

use of org.datanucleus.ExecutionContext in project datanucleus-rdbms by datanucleus.

the class AbstractArrayStore method add.

/**
 * Adds one element to the association owner vs elements
 * @param op ObjectProvider for the container
 * @param element The element to add
 * @param position The position to add this element at
 * @return Whether it was successful
 */
public boolean add(ObjectProvider op, E element, int position) {
    ExecutionContext ec = op.getExecutionContext();
    validateElementForWriting(ec, element, null);
    boolean modified = false;
    try {
        ManagedConnection mconn = storeMgr.getConnectionManager().getConnection(ec);
        try {
            // Add a row to the join table
            int[] returnCode = internalAdd(op, element, mconn, false, position, true);
            if (returnCode[0] > 0) {
                modified = true;
            }
        } finally {
            mconn.release();
        }
    } catch (MappedDatastoreException e) {
        throw new NucleusDataStoreException(Localiser.msg("056009", e.getMessage()), e.getCause());
    }
    return modified;
}

Example 58 with ExecutionContext

use of org.datanucleus.ExecutionContext in project datanucleus-rdbms by datanucleus.

the class LocateRequest method execute.

/**
 * Method performing the retrieval of the record from the datastore.
 * Takes the constructed retrieval query and populates with the specific record information.
 * @param op ObjectProvider for the record to be retrieved
 */
public void execute(ObjectProvider op) {
    if (statementLocked != null) {
        ExecutionContext ec = op.getExecutionContext();
        RDBMSStoreManager storeMgr = table.getStoreManager();
        boolean locked = ec.getSerializeReadForClass(op.getClassMetaData().getFullClassName());
        LockMode lockType = ec.getLockManager().getLockMode(op.getInternalObjectId());
        if (lockType != LockMode.LOCK_NONE) {
            if (lockType == LockMode.LOCK_PESSIMISTIC_READ || lockType == LockMode.LOCK_PESSIMISTIC_WRITE) {
                // Override with pessimistic lock
                locked = true;
            }
        }
        String statement = (locked ? statementLocked : statementUnlocked);
        try {
            ManagedConnection mconn = storeMgr.getConnectionManager().getConnection(ec);
            SQLController sqlControl = storeMgr.getSQLController();
            try {
                PreparedStatement ps = sqlControl.getStatementForQuery(mconn, statement);
                AbstractClassMetaData cmd = op.getClassMetaData();
                try {
                    // Provide the primary key field(s)
                    if (cmd.getIdentityType() == IdentityType.DATASTORE) {
                        StatementMappingIndex datastoreIdx = mappingDefinition.getMappingForMemberPosition(SurrogateColumnType.DATASTORE_ID.getFieldNumber());
                        for (int i = 0; i < datastoreIdx.getNumberOfParameterOccurrences(); i++) {
                            table.getSurrogateMapping(SurrogateColumnType.DATASTORE_ID, false).setObject(ec, ps, datastoreIdx.getParameterPositionsForOccurrence(i), op.getInternalObjectId());
                        }
                    } else if (cmd.getIdentityType() == IdentityType.APPLICATION) {
                        op.provideFields(cmd.getPKMemberPositions(), new ParameterSetter(op, ps, mappingDefinition));
                    }
                    JavaTypeMapping multitenancyMapping = table.getSurrogateMapping(SurrogateColumnType.MULTITENANCY, false);
                    if (multitenancyMapping != null) {
                        // Set MultiTenancy parameter in statement
                        StatementMappingIndex multitenancyIdx = mappingDefinition.getMappingForMemberPosition(SurrogateColumnType.MULTITENANCY.getFieldNumber());
                        String tenantId = ec.getNucleusContext().getMultiTenancyId(ec, cmd);
                        for (int i = 0; i < multitenancyIdx.getNumberOfParameterOccurrences(); i++) {
                            multitenancyMapping.setObject(ec, ps, multitenancyIdx.getParameterPositionsForOccurrence(i), tenantId);
                        }
                    }
                    JavaTypeMapping softDeleteMapping = table.getSurrogateMapping(SurrogateColumnType.SOFTDELETE, false);
                    if (softDeleteMapping != null) {
                        // Set SoftDelete parameter in statement
                        StatementMappingIndex softDeleteIdx = mappingDefinition.getMappingForMemberPosition(SurrogateColumnType.SOFTDELETE.getFieldNumber());
                        for (int i = 0; i < softDeleteIdx.getNumberOfParameterOccurrences(); i++) {
                            softDeleteMapping.setObject(ec, ps, softDeleteIdx.getParameterPositionsForOccurrence(i), Boolean.FALSE);
                        }
                    }
                    // Execute the statement
                    ResultSet rs = sqlControl.executeStatementQuery(ec, mconn, statement, ps);
                    try {
                        if (!rs.next()) {
                            NucleusLogger.DATASTORE_RETRIEVE.info(Localiser.msg("050018", op.getInternalObjectId()));
                            throw new NucleusObjectNotFoundException("No such database row", op.getInternalObjectId());
                        }
                    } finally {
                        rs.close();
                    }
                } finally {
                    sqlControl.closeStatement(mconn, ps);
                }
            } finally {
                mconn.release();
            }
        } catch (SQLException sqle) {
            String msg = Localiser.msg("052220", op.getObjectAsPrintable(), statement, sqle.getMessage());
            NucleusLogger.DATASTORE_RETRIEVE.warn(msg);
            List exceptions = new ArrayList();
            exceptions.add(sqle);
            while ((sqle = sqle.getNextException()) != null) {
                exceptions.add(sqle);
            }
            throw new NucleusDataStoreException(msg, (Throwable[]) exceptions.toArray(new Throwable[exceptions.size()]));
        }
    }
}

Example 59 with ExecutionContext

use of org.datanucleus.ExecutionContext in project datanucleus-rdbms by datanucleus.

the class UpdateRequest method execute.

/**
 * Method performing the update of the record in the datastore.
 * Takes the constructed update query and populates with the specific record information.
 * @param op The ObjectProvider for the record to be updated
 */
public void execute(ObjectProvider op) {
    // Choose the statement based on whether optimistic or not
    String stmt = null;
    ExecutionContext ec = op.getExecutionContext();
    boolean optimisticChecks = (versionMetaData != null && ec.getTransaction().getOptimistic() && versionChecks);
    stmt = optimisticChecks ? updateStmtOptimistic : updateStmt;
    if (stmt != null) {
        // TODO Support surrogate update user/timestamp
        AbstractMemberMetaData[] mmds = cmd.getManagedMembers();
        for (int i = 0; i < mmds.length; i++) {
            if (// TODO Make this accessible from cmd
            mmds[i].isUpdateTimestamp()) {
                op.replaceField(mmds[i].getAbsoluteFieldNumber(), new Timestamp(ec.getTransaction().getIsActive() ? ec.getTransaction().getBeginTime() : System.currentTimeMillis()));
            } else if (// TODO Make this accessible from cmd
            mmds[i].isUpdateUser()) {
                op.replaceField(mmds[i].getAbsoluteFieldNumber(), ec.getNucleusContext().getCurrentUser(ec));
            }
        }
        if (NucleusLogger.PERSISTENCE.isDebugEnabled()) {
            // Debug info about fields being updated
            StringBuilder fieldStr = new StringBuilder();
            if (updateFieldNumbers != null) {
                for (int i = 0; i < updateFieldNumbers.length; i++) {
                    if (fieldStr.length() > 0) {
                        fieldStr.append(",");
                    }
                    fieldStr.append(cmd.getMetaDataForManagedMemberAtAbsolutePosition(updateFieldNumbers[i]).getName());
                }
            }
            if (versionMetaData != null && versionMetaData.getFieldName() == null) {
                if (fieldStr.length() > 0) {
                    fieldStr.append(",");
                }
                fieldStr.append("[VERSION]");
            }
            // Debug information about what we are updating
            NucleusLogger.PERSISTENCE.debug(Localiser.msg("052214", op.getObjectAsPrintable(), fieldStr.toString(), table));
        }
        RDBMSStoreManager storeMgr = table.getStoreManager();
        boolean batch = false;
        // TODO Set the batch flag based on whether we have no other SQL being invoked in here just our UPDATE
        try {
            ManagedConnection mconn = storeMgr.getConnectionManager().getConnection(ec);
            SQLController sqlControl = storeMgr.getSQLController();
            try {
                // Perform the update
                PreparedStatement ps = sqlControl.getStatementForUpdate(mconn, stmt, batch);
                try {
                    Object currentVersion = op.getTransactionalVersion();
                    Object nextVersion = null;
                    if (// TODO What if strategy is NONE?
                    versionMetaData != null) {
                        // Set the next version in the object
                        if (versionMetaData.getFieldName() != null) {
                            // Version field
                            AbstractMemberMetaData verfmd = cmd.getMetaDataForMember(table.getVersionMetaData().getFieldName());
                            if (currentVersion instanceof Number) {
                                // Cater for Integer-based versions
                                currentVersion = Long.valueOf(((Number) currentVersion).longValue());
                            }
                            nextVersion = ec.getLockManager().getNextVersion(versionMetaData, currentVersion);
                            if (verfmd.getType() == Integer.class || verfmd.getType() == int.class) {
                                // Cater for Integer-based versions
                                nextVersion = Integer.valueOf(((Number) nextVersion).intValue());
                            }
                            op.replaceField(verfmd.getAbsoluteFieldNumber(), nextVersion);
                        } else {
                            // Surrogate version column
                            nextVersion = ec.getLockManager().getNextVersion(versionMetaData, currentVersion);
                        }
                        op.setTransactionalVersion(nextVersion);
                    }
                    // SELECT clause - set the required fields to be updated
                    if (updateFieldNumbers != null) {
                        StatementClassMapping mappingDefinition = new StatementClassMapping();
                        StatementMappingIndex[] idxs = stmtMappingDefinition.getUpdateFields();
                        for (int i = 0; i < idxs.length; i++) {
                            if (idxs[i] != null) {
                                mappingDefinition.addMappingForMember(i, idxs[i]);
                            }
                        }
                        op.provideFields(updateFieldNumbers, new ParameterSetter(op, ps, mappingDefinition));
                    }
                    if (versionMetaData != null && versionMetaData.getFieldName() == null) {
                        // SELECT clause - set the surrogate version column to the new version
                        StatementMappingIndex mapIdx = stmtMappingDefinition.getUpdateVersion();
                        for (int i = 0; i < mapIdx.getNumberOfParameterOccurrences(); i++) {
                            table.getSurrogateMapping(SurrogateColumnType.VERSION, false).setObject(ec, ps, mapIdx.getParameterPositionsForOccurrence(i), nextVersion);
                        }
                    }
                    // WHERE clause - primary key fields
                    if (table.getIdentityType() == IdentityType.DATASTORE) {
                        // a). datastore identity
                        StatementMappingIndex mapIdx = stmtMappingDefinition.getWhereDatastoreId();
                        for (int i = 0; i < mapIdx.getNumberOfParameterOccurrences(); i++) {
                            table.getSurrogateMapping(SurrogateColumnType.DATASTORE_ID, false).setObject(ec, ps, mapIdx.getParameterPositionsForOccurrence(i), op.getInternalObjectId());
                        }
                    } else {
                        // b). application/nondurable identity
                        StatementClassMapping mappingDefinition = new StatementClassMapping();
                        StatementMappingIndex[] idxs = stmtMappingDefinition.getWhereFields();
                        for (int i = 0; i < idxs.length; i++) {
                            if (idxs[i] != null) {
                                mappingDefinition.addMappingForMember(i, idxs[i]);
                            }
                        }
                        FieldManager fm = null;
                        if (cmd.getIdentityType() == IdentityType.NONDURABLE) {
                            fm = new OldValueParameterSetter(op, ps, mappingDefinition);
                        } else {
                            fm = new ParameterSetter(op, ps, mappingDefinition);
                        }
                        op.provideFields(whereFieldNumbers, fm);
                    }
                    if (optimisticChecks) {
                        if (currentVersion == null) {
                            // Somehow the version is not set on this object (not read in ?) so report the bug
                            String msg = Localiser.msg("052201", op.getInternalObjectId(), table);
                            NucleusLogger.PERSISTENCE.error(msg);
                            throw new NucleusException(msg);
                        }
                        // WHERE clause - current version discriminator
                        StatementMappingIndex mapIdx = stmtMappingDefinition.getWhereVersion();
                        for (int i = 0; i < mapIdx.getNumberOfParameterOccurrences(); i++) {
                            mapIdx.getMapping().setObject(ec, ps, mapIdx.getParameterPositionsForOccurrence(i), currentVersion);
                        }
                    }
                    int[] rcs = sqlControl.executeStatementUpdate(ec, mconn, stmt, ps, !batch);
                    if (rcs[0] == 0 && optimisticChecks) {
                        // TODO Batching : when we use batching here we need to process these somehow
                        throw new NucleusOptimisticException(Localiser.msg("052203", op.getObjectAsPrintable(), op.getInternalObjectId(), "" + currentVersion), op.getObject());
                    }
                } finally {
                    sqlControl.closeStatement(mconn, ps);
                }
            } finally {
                mconn.release();
            }
        } catch (SQLException e) {
            String msg = Localiser.msg("052215", op.getObjectAsPrintable(), stmt, StringUtils.getStringFromStackTrace(e));
            NucleusLogger.DATASTORE_PERSIST.error(msg);
            List exceptions = new ArrayList();
            exceptions.add(e);
            while ((e = e.getNextException()) != null) {
                exceptions.add(e);
            }
            throw new NucleusDataStoreException(msg, (Throwable[]) exceptions.toArray(new Throwable[exceptions.size()]));
        }
    }
    // Execute any mapping actions now that we have done the update
    for (int i = 0; i < callbacks.length; ++i) {
        try {
            if (NucleusLogger.PERSISTENCE.isDebugEnabled()) {
                NucleusLogger.PERSISTENCE.debug(Localiser.msg("052216", op.getObjectAsPrintable(), ((JavaTypeMapping) callbacks[i]).getMemberMetaData().getFullFieldName()));
            }
            callbacks[i].postUpdate(op);
        } catch (NotYetFlushedException e) {
            op.updateFieldAfterInsert(e.getPersistable(), ((JavaTypeMapping) callbacks[i]).getMemberMetaData().getAbsoluteFieldNumber());
        }
    }
}

Example 60 with ExecutionContext

use of org.datanucleus.ExecutionContext in project datanucleus-rdbms by datanucleus.

the class ExpressionUtils method getEqualityExpressionForObjectExpressions.

/**
 * Method to generate an equality/inequality expression between two ObjectExpressions.
 * Either or both of the expressions can be ObjectLiterals.
 * @param expr1 First expression
 * @param expr2 Second expression
 * @param equals Whether it is equality (otherwise inequality)
 * @return The expression
 */
public static BooleanExpression getEqualityExpressionForObjectExpressions(ObjectExpression expr1, ObjectExpression expr2, boolean equals) {
    SQLStatement stmt = expr1.stmt;
    RDBMSStoreManager storeMgr = stmt.getRDBMSManager();
    SQLExpressionFactory exprFactory = storeMgr.getSQLExpressionFactory();
    ClassLoaderResolver clr = stmt.getClassLoaderResolver();
    ApiAdapter api = storeMgr.getApiAdapter();
    if (expr1 instanceof ObjectLiteral && expr2 instanceof ObjectLiteral) {
        // ObjectLiterall == ObjectLiteral
        ObjectLiteral lit1 = (ObjectLiteral) expr1;
        ObjectLiteral lit2 = (ObjectLiteral) expr2;
        return new BooleanLiteral(stmt, expr1.mapping, equals ? lit1.getValue().equals(lit2.getValue()) : !lit1.getValue().equals(lit2.getValue()));
    } else if (expr1 instanceof ObjectLiteral || expr2 instanceof ObjectLiteral) {
        // ObjectExpression == ObjectLiteral, ObjectLiteral == ObjectExpression
        BooleanExpression bExpr = null;
        boolean secondIsLiteral = (expr2 instanceof ObjectLiteral);
        Object value = (!secondIsLiteral ? ((ObjectLiteral) expr1).getValue() : ((ObjectLiteral) expr2).getValue());
        if (IdentityUtils.isDatastoreIdentity(value)) {
            // Object is an OID
            Object valueKey = IdentityUtils.getTargetKeyForDatastoreIdentity(value);
            JavaTypeMapping m = storeMgr.getSQLExpressionFactory().getMappingForType(valueKey.getClass(), false);
            SQLExpression oidLit = exprFactory.newLiteral(stmt, m, valueKey);
            if (equals) {
                return (secondIsLiteral ? expr1.subExprs.getExpression(0).eq(oidLit) : expr2.subExprs.getExpression(0).eq(oidLit));
            }
            return (secondIsLiteral ? expr1.subExprs.getExpression(0).ne(oidLit) : expr2.subExprs.getExpression(0).ne(oidLit));
        } else if (IdentityUtils.isSingleFieldIdentity(value)) {
            // Object is SingleFieldIdentity
            Object valueKey = IdentityUtils.getTargetKeyForSingleFieldIdentity(value);
            // This used to use ((SingleFieldId)value).getTargetClass() for some reason, which contradicts the above datastore id method
            JavaTypeMapping m = storeMgr.getSQLExpressionFactory().getMappingForType(valueKey.getClass(), false);
            SQLExpression oidLit = exprFactory.newLiteral(stmt, m, valueKey);
            if (equals) {
                return (secondIsLiteral ? expr1.subExprs.getExpression(0).eq(oidLit) : expr2.subExprs.getExpression(0).eq(oidLit));
            }
            return (secondIsLiteral ? expr1.subExprs.getExpression(0).ne(oidLit) : expr2.subExprs.getExpression(0).ne(oidLit));
        } else {
            AbstractClassMetaData cmd = storeMgr.getNucleusContext().getMetaDataManager().getMetaDataForClass(value.getClass(), clr);
            if (cmd != null) {
                // Value is a persistable object
                if (cmd.getIdentityType() == IdentityType.APPLICATION) {
                    // Application identity
                    if (api.getIdForObject(value) != null) {
                        // Persistent PC object (FCO)
                        // Cater for composite PKs and parts of PK being PC mappings, and recursion
                        ObjectExpression expr = (secondIsLiteral ? expr1 : expr2);
                        JavaTypeMapping[] pkMappingsApp = new JavaTypeMapping[expr.subExprs.size()];
                        Object[] pkFieldValues = new Object[expr.subExprs.size()];
                        int position = 0;
                        ExecutionContext ec = api.getExecutionContext(value);
                        JavaTypeMapping thisMapping = expr.mapping;
                        if (expr.mapping instanceof ReferenceMapping) {
                            // "InterfaceField == value", so pick an implementation mapping that is castable
                            thisMapping = null;
                            ReferenceMapping refMapping = (ReferenceMapping) expr.mapping;
                            JavaTypeMapping[] implMappings = refMapping.getJavaTypeMapping();
                            for (int i = 0; i < implMappings.length; i++) {
                                Class implType = clr.classForName(implMappings[i].getType());
                                if (implType.isAssignableFrom(value.getClass())) {
                                    thisMapping = implMappings[i];
                                    break;
                                }
                            }
                        }
                        if (thisMapping == null) {
                            // Just return a (1=0) since no implementation castable
                            return exprFactory.newLiteral(stmt, expr1.mapping, false).eq(exprFactory.newLiteral(stmt, expr1.mapping, true));
                        }
                        for (int i = 0; i < cmd.getNoOfPrimaryKeyMembers(); i++) {
                            AbstractMemberMetaData mmd = cmd.getMetaDataForManagedMemberAtAbsolutePosition(cmd.getPKMemberPositions()[i]);
                            Object fieldValue = ExpressionUtils.getValueForMemberOfObject(ec, mmd, value);
                            JavaTypeMapping mapping = ((PersistableMapping) thisMapping).getJavaTypeMapping()[i];
                            if (mapping instanceof PersistableMapping) {
                                position = ExpressionUtils.populatePrimaryKeyMappingsValuesForPCMapping(pkMappingsApp, pkFieldValues, position, (PersistableMapping) mapping, cmd, mmd, fieldValue, storeMgr, clr);
                            } else {
                                pkMappingsApp[position] = mapping;
                                pkFieldValues[position] = fieldValue;
                                position++;
                            }
                        }
                        for (int i = 0; i < expr.subExprs.size(); i++) {
                            SQLExpression source = expr.subExprs.getExpression(i);
                            SQLExpression target = exprFactory.newLiteral(stmt, pkMappingsApp[i], pkFieldValues[i]);
                            BooleanExpression subExpr = (secondIsLiteral ? source.eq(target) : target.eq(source));
                            if (bExpr == null) {
                                bExpr = subExpr;
                            } else {
                                bExpr = bExpr.and(subExpr);
                            }
                        }
                    } else {
                        // PC object with no id (embedded, or transient maybe)
                        if (secondIsLiteral) {
                            for (int i = 0; i < expr1.subExprs.size(); i++) {
                                // Query should return nothing (so just do "(1 = 0)")
                                NucleusLogger.QUERY.warn(Localiser.msg("037003", value));
                                bExpr = exprFactory.newLiteral(stmt, expr1.mapping, false).eq(exprFactory.newLiteral(stmt, expr1.mapping, true));
                            // It is arguable that we should compare the id with null (as below)
                            /*bExpr = expr.eq(new NullLiteral(qs));*/
                            }
                        } else {
                            for (int i = 0; i < expr2.subExprs.size(); i++) {
                                // Query should return nothing (so just do "(1 = 0)")
                                NucleusLogger.QUERY.warn(Localiser.msg("037003", value));
                                bExpr = exprFactory.newLiteral(stmt, expr2.mapping, false).eq(exprFactory.newLiteral(stmt, expr2.mapping, true));
                            // It is arguable that we should compare the id with null (as below)
                            /*bExpr = expr.eq(new NullLiteral(qs));*/
                            }
                        }
                    }
                    // TODO Allow for !equals
                    return bExpr;
                } else if (cmd.getIdentityType() == IdentityType.DATASTORE) {
                    // Datastore identity
                    SQLExpression source = (secondIsLiteral ? expr1.subExprs.getExpression(0) : expr2.subExprs.getExpression(0));
                    JavaTypeMapping mapping = (secondIsLiteral ? expr1.mapping : expr2.mapping);
                    Object objectId = api.getIdForObject(value);
                    if (objectId == null) {
                        // PC object with no id (embedded, or transient maybe)
                        // Query should return nothing (so just do "(1 = 0)")
                        NucleusLogger.QUERY.warn(Localiser.msg("037003", value));
                        // TODO Allow for !equals
                        return exprFactory.newLiteral(stmt, mapping, false).eq(exprFactory.newLiteral(stmt, mapping, true));
                    // It is arguable that we should compare the id with null (as below)
                    /*bExpr = expr.eq(new NullLiteral(qs));*/
                    }
                    Object objectIdKey = IdentityUtils.getTargetKeyForDatastoreIdentity(objectId);
                    JavaTypeMapping m = storeMgr.getSQLExpressionFactory().getMappingForType(objectIdKey.getClass(), false);
                    SQLExpression oidExpr = exprFactory.newLiteral(stmt, m, objectIdKey);
                    if (equals) {
                        return source.eq(oidExpr);
                    }
                    return source.ne(oidExpr);
                }
            } else {
                // No metadata, so we either have an application identity, or any object
                String pcClassName = storeMgr.getClassNameForObjectID(value, clr, null);
                if (pcClassName != null) {
                    // Object is an application identity
                    cmd = storeMgr.getNucleusContext().getMetaDataManager().getMetaDataForClass(pcClassName, clr);
                    return (secondIsLiteral ? ExpressionUtils.getAppIdEqualityExpression(value, expr1, storeMgr, clr, cmd, null, null) : ExpressionUtils.getAppIdEqualityExpression(value, expr2, storeMgr, clr, cmd, null, null));
                // TODO Allow for !equals
                }
                // Value not persistable nor an identity, so return nothing "(1 = 0)"
                return exprFactory.newLiteral(stmt, expr1.mapping, false).eq(exprFactory.newLiteral(stmt, expr1.mapping, true));
            // TODO Allow for !equals
            }
        }
    } else {
        // ObjectExpression == ObjectExpression
        BooleanExpression resultExpr = null;
        for (int i = 0; i < expr1.subExprs.size(); i++) {
            SQLExpression sourceExpr = expr1.subExprs.getExpression(i);
            SQLExpression targetExpr = expr2.subExprs.getExpression(i);
            if (resultExpr == null) {
                resultExpr = sourceExpr.eq(targetExpr);
            } else {
                resultExpr = resultExpr.and(sourceExpr.eq(targetExpr));
            }
        }
        if (!equals) {
            resultExpr = new BooleanExpression(Expression.OP_NOT, resultExpr != null ? resultExpr.encloseInParentheses() : null);
        }
        return resultExpr;
    }
    return null;
}