Examples with TypeExpression org.datanucleus.query.expression.TypeExpression used on opensource projects

Example 1 with TypeExpression

use of org.datanucleus.query.expression.TypeExpression in project datanucleus-rdbms by datanucleus.

the class QueryToSQLMapper method compileResult.

/**
 * Method to compile the result clause of the query into the SQLStatement.
 * Note that this also compiles queries of the candidate (no specified result), selecting the candidate field(s).
 * @param stmt SELECT statement
 */
protected void compileResult(SelectStatement stmt) {
    compileComponent = CompilationComponent.RESULT;
    boolean unionsPresent = stmt.getNumberOfUnions() > 0;
    // TODO Cater for more expression types where we have UNIONs and select each UNION separately
    if (compilation.getExprResult() != null) {
        // Select any result expressions
        Expression[] resultExprs = compilation.getExprResult();
        for (int i = 0; i < resultExprs.length; i++) {
            String alias = resultExprs[i].getAlias();
            if (alias != null && resultAliases == null) {
                resultAliases = new HashSet<>();
            }
            if (resultExprs[i] instanceof InvokeExpression || resultExprs[i] instanceof ParameterExpression || resultExprs[i] instanceof Literal) {
                // Process expressions that need no special treatment
                if (resultExprs[i] instanceof InvokeExpression) {
                    processInvokeExpression((InvokeExpression) resultExprs[i]);
                } else if (resultExprs[i] instanceof ParameterExpression) {
                    // Second argument : parameters are literals in result
                    processParameterExpression((ParameterExpression) resultExprs[i], true);
                } else {
                    processLiteral((Literal) resultExprs[i]);
                }
                SQLExpression sqlExpr = stack.pop();
                validateExpressionForResult(sqlExpr);
                int[] cols = stmt.select(sqlExpr, alias);
                StatementMappingIndex idx = new StatementMappingIndex(sqlExpr.getJavaTypeMapping());
                idx.setColumnPositions(cols);
                if (alias != null) {
                    resultAliases.add(alias);
                    idx.setColumnAlias(alias);
                }
                resultDefinition.addMappingForResultExpression(i, idx);
            } else if (resultExprs[i] instanceof PrimaryExpression) {
                PrimaryExpression primExpr = (PrimaryExpression) resultExprs[i];
                if (primExpr.getId().equals(candidateAlias)) {
                    // "this", so select fetch plan fields
                    if (unionsPresent) {
                        // Process the first union separately (in case they have TYPE/instanceof) and then handle remaining UNIONs below
                        stmt.setAllowUnions(false);
                    }
                    StatementClassMapping map = new StatementClassMapping(candidateCmd.getFullClassName(), null);
                    SQLStatementHelper.selectFetchPlanOfCandidateInStatement(stmt, map, candidateCmd, fetchPlan, 1);
                    resultDefinition.addMappingForResultExpression(i, map);
                    if (unionsPresent) {
                        // Process remaining UNIONs. Assumed that we have the same result mapping as the first UNION otherwise SQL wouldn't work anyway
                        stmt.setAllowUnions(true);
                        List<SelectStatement> unionStmts = stmt.getUnions();
                        SelectStatement originalStmt = stmt;
                        for (SelectStatement unionStmt : unionStmts) {
                            this.stmt = unionStmt;
                            unionStmt.setQueryGenerator(this);
                            unionStmt.setAllowUnions(false);
                            StatementClassMapping dummyClsMapping = new StatementClassMapping(candidateCmd.getFullClassName(), null);
                            SQLStatementHelper.selectFetchPlanOfCandidateInStatement(unionStmt, dummyClsMapping, candidateCmd, fetchPlan, 1);
                            unionStmt.setQueryGenerator(null);
                            unionStmt.setAllowUnions(true);
                        }
                        this.stmt = originalStmt;
                    }
                } else {
                    processPrimaryExpression(primExpr);
                    SQLExpression sqlExpr = stack.pop();
                    validateExpressionForResult(sqlExpr);
                    if (primExpr.getId().endsWith("#KEY") || primExpr.getId().endsWith("#VALUE")) {
                        // JPQL KEY(map) or VALUE(map), so select FetchPlan fields where persistable
                        if (sqlExpr.getJavaTypeMapping() instanceof PersistableMapping) {
                            // Method returns persistable object, so select the FetchPlan
                            String selectedType = ((PersistableMapping) sqlExpr.getJavaTypeMapping()).getType();
                            AbstractClassMetaData selectedCmd = ec.getMetaDataManager().getMetaDataForClass(selectedType, clr);
                            FetchPlanForClass fpForCmd = fetchPlan.getFetchPlanForClass(selectedCmd);
                            int[] membersToSelect = fpForCmd.getMemberNumbers();
                            ClassTable selectedTable = (ClassTable) sqlExpr.getSQLTable().getTable();
                            StatementClassMapping map = new StatementClassMapping(selectedCmd.getFullClassName(), null);
                            if (selectedCmd.getIdentityType() == IdentityType.DATASTORE) {
                                int[] cols = stmt.select(sqlExpr.getSQLTable(), selectedTable.getSurrogateMapping(SurrogateColumnType.DATASTORE_ID, false), alias);
                                StatementMappingIndex idx = new StatementMappingIndex(selectedTable.getSurrogateMapping(SurrogateColumnType.DATASTORE_ID, false));
                                idx.setColumnPositions(cols);
                                map.addMappingForMember(SurrogateColumnType.DATASTORE_ID.getFieldNumber(), idx);
                            }
                            // Select the FetchPlan members
                            for (int memberToSelect : membersToSelect) {
                                AbstractMemberMetaData selMmd = selectedCmd.getMetaDataForManagedMemberAtAbsolutePosition(memberToSelect);
                                // TODO Arbitrary penultimate argument
                                SQLStatementHelper.selectMemberOfSourceInStatement(stmt, map, fetchPlan, sqlExpr.getSQLTable(), selMmd, clr, 1, null);
                            }
                            resultDefinition.addMappingForResultExpression(i, map);
                            continue;
                        } else if (sqlExpr.getJavaTypeMapping() instanceof EmbeddedMapping) {
                            // Method returns embedded object, so select the FetchPlan
                            EmbeddedMapping embMapping = (EmbeddedMapping) sqlExpr.getJavaTypeMapping();
                            AbstractClassMetaData selectedCmd = ec.getMetaDataManager().getMetaDataForClass(embMapping.getType(), clr);
                            // Select the FetchPlan members
                            StatementClassMapping map = new StatementClassMapping(selectedCmd.getFullClassName(), null);
                            int[] membersToSelect = fetchPlan.getFetchPlanForClass(selectedCmd).getMemberNumbers();
                            for (int memberToSelect : membersToSelect) {
                                AbstractMemberMetaData selMmd = selectedCmd.getMetaDataForManagedMemberAtAbsolutePosition(memberToSelect);
                                JavaTypeMapping selMapping = embMapping.getJavaTypeMapping(selMmd.getName());
                                if (selMapping.includeInFetchStatement()) {
                                    int[] cols = stmt.select(sqlExpr.getSQLTable(), selMapping, alias);
                                    StatementMappingIndex idx = new StatementMappingIndex(selMapping);
                                    idx.setColumnPositions(cols);
                                    map.addMappingForMember(memberToSelect, idx);
                                }
                            }
                            resultDefinition.addMappingForResultExpression(i, map);
                            continue;
                        }
                    }
                    // TODO If the user selects an alias here that is joined, should maybe respect FetchPlan for that (like above for candidate)
                    // TODO Cater for use of UNIONs (e.g "complete-table" inheritance) where mapping is different in other UNION
                    // The difficulty here is that processPrimaryExpression makes use of the sqlTableByPrimary lookup, which is based on the primary statement, so
                    // it still doesn't find the right table/mapping for the UNIONed statements.
                    int[] cols = null;
                    if (sqlExpr instanceof SQLLiteral) {
                        cols = stmt.select(sqlExpr, alias);
                    } else {
                        cols = stmt.select(sqlExpr.getSQLTable(), sqlExpr.getJavaTypeMapping(), alias);
                    }
                    StatementMappingIndex idx = new StatementMappingIndex(sqlExpr.getJavaTypeMapping());
                    idx.setColumnPositions(cols);
                    if (alias != null) {
                        resultAliases.add(alias);
                        idx.setColumnAlias(alias);
                    }
                    resultDefinition.addMappingForResultExpression(i, idx);
                }
            } else if (resultExprs[i] instanceof VariableExpression) {
                // Subquery?
                processVariableExpression((VariableExpression) resultExprs[i]);
                SQLExpression sqlExpr = stack.pop();
                validateExpressionForResult(sqlExpr);
                if (sqlExpr instanceof UnboundExpression) {
                    // Variable wasn't bound in the compilation so far, so handle as cross-join
                    processUnboundExpression((UnboundExpression) sqlExpr);
                    sqlExpr = stack.pop();
                    NucleusLogger.QUERY.debug("QueryToSQL.exprResult variable was still unbound, so binding via cross-join");
                }
                int[] cols = stmt.select(sqlExpr, alias);
                StatementMappingIndex idx = new StatementMappingIndex(sqlExpr.getJavaTypeMapping());
                idx.setColumnPositions(cols);
                if (alias != null) {
                    resultAliases.add(alias);
                    idx.setColumnAlias(alias);
                }
                resultDefinition.addMappingForResultExpression(i, idx);
            } else if (resultExprs[i] instanceof TypeExpression) {
                // TYPE(identification_variable | single_valued_path_expr | input_parameter)
                TypeExpression typeExpr = (TypeExpression) resultExprs[i];
                Expression containedExpr = typeExpr.getContainedExpression();
                if (containedExpr instanceof PrimaryExpression) {
                    processPrimaryExpression((PrimaryExpression) containedExpr);
                    SQLExpression sqlExpr = stack.pop();
                    JavaTypeMapping discrimMapping = sqlExpr.getSQLTable().getTable().getSurrogateMapping(SurrogateColumnType.DISCRIMINATOR, true);
                    if (discrimMapping == null) {
                        // TODO If we have a UNIONED primary expression then it would be possible to just select the DN_TYPE from the particular union
                        throw new NucleusException("Result has call to " + typeExpr + " but contained expression has no discriminator. Not supported");
                    }
                    int[] cols = stmt.select(sqlExpr.getSQLTable(), discrimMapping, null, true);
                    StatementMappingIndex idx = new StatementMappingIndex(discrimMapping);
                    idx.setColumnPositions(cols);
                    resultDefinition.addMappingForResultExpression(i, idx);
                } else {
                    throw new NucleusException("Result has call to " + typeExpr + " but contained expression not supported");
                }
            } else if (resultExprs[i] instanceof CreatorExpression) {
                processCreatorExpression((CreatorExpression) resultExprs[i]);
                NewObjectExpression sqlExpr = (NewObjectExpression) stack.pop();
                StatementNewObjectMapping stmtMap = getStatementMappingForNewObjectExpression(sqlExpr, stmt);
                resultDefinition.addMappingForResultExpression(i, stmtMap);
            } else if (resultExprs[i] instanceof DyadicExpression || resultExprs[i] instanceof CaseExpression) {
                if (unionsPresent) {
                    // Process the first union separately (in case they have TYPE/instanceof) and then handle remaining UNIONs below
                    stmt.setAllowUnions(false);
                }
                resultExprs[i].evaluate(this);
                SQLExpression sqlExpr = stack.pop();
                int[] cols = stmt.select(sqlExpr, alias);
                StatementMappingIndex idx = new StatementMappingIndex(sqlExpr.getJavaTypeMapping());
                idx.setColumnPositions(cols);
                if (alias != null) {
                    resultAliases.add(alias);
                    idx.setColumnAlias(alias);
                }
                resultDefinition.addMappingForResultExpression(i, idx);
                if (unionsPresent) {
                    // Process remaining UNIONs. Assumed that we have the same result mapping as the first UNION otherwise SQL wouldn't work anyway
                    stmt.setAllowUnions(true);
                    List<SelectStatement> unionStmts = stmt.getUnions();
                    SelectStatement originalStmt = stmt;
                    for (SelectStatement unionStmt : unionStmts) {
                        this.stmt = unionStmt;
                        unionStmt.setQueryGenerator(this);
                        unionStmt.setAllowUnions(false);
                        resultExprs[i].evaluate(this);
                        sqlExpr = stack.pop();
                        unionStmt.select(sqlExpr, alias);
                        unionStmt.setQueryGenerator(null);
                        unionStmt.setAllowUnions(true);
                    }
                    this.stmt = originalStmt;
                }
            } else {
                throw new NucleusException("Dont currently support result clause containing expression of type " + resultExprs[i]);
            }
        }
        if (stmt.getNumberOfSelects() == 0) {
            // Nothing selected so likely the user had some "new MyClass()" expression, so select "1"
            stmt.select(exprFactory.newLiteral(stmt, storeMgr.getMappingManager().getMapping(Integer.class), 1), null);
        }
    } else {
        // Select of the candidate (no result)
        if (candidateCmd.getIdentityType() == IdentityType.NONDURABLE) {
            // Nondurable identity cases have no "id" for later fetching so get all fields now
            if (NucleusLogger.QUERY.isDebugEnabled()) {
                NucleusLogger.QUERY.debug(Localiser.msg("052520", candidateCmd.getFullClassName()));
            }
            fetchPlan.setGroup("all");
        }
        if (subclasses) {
        // TODO Check for special case of candidate+subclasses stores in same table with discriminator, so select FetchGroup of subclasses also
        }
        int maxFetchDepth = fetchPlan.getMaxFetchDepth();
        if (maxFetchDepth < 0) {
            NucleusLogger.QUERY.debug("No limit specified on query fetch so limiting to 3 levels from candidate. " + "Specify the '" + PropertyNames.PROPERTY_MAX_FETCH_DEPTH + "' to override this");
            // TODO Arbitrary
            maxFetchDepth = 3;
        }
        // This means that we then cater for a UNION using a different column name than the primary statement
        if (unionsPresent) {
            // Process the first union separately (in case they have TYPE/instanceof) and then handle remaining UNIONs below
            stmt.setAllowUnions(false);
        }
        selectFetchPlanForCandidate(stmt, resultDefinitionForClass, maxFetchDepth);
        if (unionsPresent) {
            // Process remaining UNIONs. Assumed that we have the same result mapping as the first UNION otherwise SQL wouldn't work anyway
            stmt.setAllowUnions(true);
            List<SelectStatement> unionStmts = stmt.getUnions();
            SelectStatement originalStmt = stmt;
            for (SelectStatement unionStmt : unionStmts) {
                this.stmt = unionStmt;
                unionStmt.setQueryGenerator(this);
                unionStmt.setAllowUnions(false);
                // We don't want to overwrite anything in the root StatementClassMapping
                StatementClassMapping dummyResClsMapping = new StatementClassMapping();
                selectFetchPlanForCandidate(unionStmt, dummyResClsMapping, maxFetchDepth);
                unionStmt.setQueryGenerator(null);
                unionStmt.setAllowUnions(true);
            }
            this.stmt = originalStmt;
        }
    }
    compileComponent = null;
}