Examples with DiscriminatorMapping org.datanucleus.store.rdbms.mapping.java.DiscriminatorMapping used on opensource projects

Example 1 with DiscriminatorMapping

use of org.datanucleus.store.rdbms.mapping.java.DiscriminatorMapping in project datanucleus-rdbms by datanucleus.

the class ObjectExpression method is.

/**
 * An "is" (instanceOf) expression, providing a BooleanExpression whether this expression is an instanceof the provided type.
 * @param expr The expression representing the type
 * @param not Whether the operator is "!instanceof"
 * @return Whether this expression is an instance of the provided type
 */
public BooleanExpression is(SQLExpression expr, boolean not) {
    RDBMSStoreManager storeMgr = stmt.getRDBMSManager();
    ClassLoaderResolver clr = stmt.getClassLoaderResolver();
    // Extract instanceOf type
    String instanceofClassName = null;
    SQLExpression classExpr = expr;
    if (expr instanceof TypeConverterLiteral) {
        // For some reason the user has input "TYPE(field) = :param" and param is a type-converted value
        classExpr = ((TypeConverterLiteral) expr).getDelegate();
    }
    if (classExpr instanceof StringLiteral) {
        instanceofClassName = (String) ((StringLiteral) classExpr).getValue();
    } else if (classExpr instanceof CollectionLiteral) {
        // "a instanceof (b1,b2,b3)"
        CollectionLiteral typesLiteral = (CollectionLiteral) classExpr;
        Collection values = (Collection) typesLiteral.getValue();
        if (values.size() == 1) {
            Object value = values.iterator().next();
            String valueStr = null;
            if (value instanceof Class) {
                valueStr = ((Class) value).getCanonicalName();
            } else if (value instanceof String) {
                valueStr = (String) value;
            } else {
                throw new NucleusUserException("Do not support CollectionLiteral of element type " + value.getClass().getName());
            }
            return is(new StringLiteral(stmt, typesLiteral.getJavaTypeMapping(), valueStr, typesLiteral.getParameterName()), not);
        }
        List<BooleanExpression> listExp = new LinkedList<>();
        for (Object value : values) {
            String valueStr = null;
            if (value instanceof Class) {
                valueStr = ((Class) value).getCanonicalName();
            } else if (value instanceof String) {
                valueStr = (String) value;
            } else {
                throw new NucleusUserException("Do not support CollectionLiteral of element type " + value.getClass().getName());
            }
            listExp.add(is(new StringLiteral(stmt, typesLiteral.getJavaTypeMapping(), valueStr, typesLiteral.getParameterName()), false));
        }
        BooleanExpression result = null;
        for (BooleanExpression sqlExpression : listExp) {
            result = result == null ? sqlExpression : result.ior(sqlExpression);
        }
        if (result != null) {
            return not ? result.not() : result;
        }
    } else {
        throw new NucleusUserException("Do not currently support `instanceof` with class expression of type " + classExpr);
    }
    Class type = null;
    try {
        type = stmt.getQueryGenerator().resolveClass(instanceofClassName);
    } catch (ClassNotResolvedException cnre) {
        type = null;
    }
    if (type == null) {
        throw new NucleusUserException(Localiser.msg("037016", instanceofClassName));
    }
    // Extract type of member and check obvious conditions
    SQLExpressionFactory exprFactory = stmt.getSQLExpressionFactory();
    Class memberType = clr.classForName(mapping.getType());
    if (!memberType.isAssignableFrom(type) && !type.isAssignableFrom(memberType)) {
        // Member type and instanceof type are totally incompatible, so just return false
        JavaTypeMapping m = exprFactory.getMappingForType(boolean.class, true);
        return exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, not));
    } else if (memberType == type) {
        // instanceof type is the same as the member type therefore must comply (can't store supertypes)
        JavaTypeMapping m = exprFactory.getMappingForType(boolean.class, true);
        return exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, !not));
    }
    if (mapping instanceof EmbeddedMapping) {
        // Don't support embedded instanceof expressions
        AbstractClassMetaData fieldCmd = storeMgr.getMetaDataManager().getMetaDataForClass(mapping.getType(), clr);
        if (fieldCmd.hasDiscriminatorStrategy()) {
            // Embedded field with inheritance so add discriminator restriction
            JavaTypeMapping discMapping = ((EmbeddedMapping) mapping).getDiscriminatorMapping();
            AbstractClassMetaData typeCmd = storeMgr.getMetaDataManager().getMetaDataForClass(type, clr);
            SQLExpression discExpr = stmt.getSQLExpressionFactory().newExpression(stmt, table, discMapping);
            SQLExpression discValExpr = stmt.getSQLExpressionFactory().newLiteral(stmt, discMapping, typeCmd.getDiscriminatorValue());
            BooleanExpression typeExpr = (not ? discExpr.ne(discValExpr) : discExpr.eq(discValExpr));
            Iterator<String> subclassIter = storeMgr.getSubClassesForClass(type.getName(), true, clr).iterator();
            while (subclassIter.hasNext()) {
                String subclassName = subclassIter.next();
                AbstractClassMetaData subtypeCmd = storeMgr.getMetaDataManager().getMetaDataForClass(subclassName, clr);
                Object subtypeDiscVal = subtypeCmd.getDiscriminatorValue();
                discValExpr = stmt.getSQLExpressionFactory().newLiteral(stmt, discMapping, subtypeDiscVal);
                BooleanExpression subtypeExpr = (not ? discExpr.ne(discValExpr) : discExpr.eq(discValExpr));
                if (not) {
                    typeExpr = typeExpr.and(subtypeExpr);
                } else {
                    typeExpr = typeExpr.ior(subtypeExpr);
                }
            }
            return typeExpr;
        }
        JavaTypeMapping m = exprFactory.getMappingForType(boolean.class, true);
        return exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, not));
    } else if (mapping instanceof PersistableMapping || mapping instanceof ReferenceMapping) {
        // Field has its own table, so join to it
        AbstractClassMetaData memberCmd = storeMgr.getMetaDataManager().getMetaDataForClass(mapping.getType(), clr);
        DatastoreClass memberTable = null;
        if (memberCmd.getInheritanceMetaData().getStrategy() == InheritanceStrategy.SUBCLASS_TABLE) {
            // Field is a PC class that uses "subclass-table" inheritance strategy (and so has multiple possible tables to join to)
            AbstractClassMetaData[] cmds = storeMgr.getClassesManagingTableForClass(memberCmd, clr);
            if (cmds != null) {
                // TODO Allow for all possible tables. Can we do an OR of the tables ? How ?
                if (cmds.length > 1) {
                    NucleusLogger.QUERY.warn(Localiser.msg("037006", mapping.getMemberMetaData().getFullFieldName(), cmds[0].getFullClassName()));
                }
                memberTable = storeMgr.getDatastoreClass(cmds[0].getFullClassName(), clr);
            } else {
                // No subclasses with tables to join to, so throw a user error
                throw new NucleusUserException(Localiser.msg("037005", mapping.getMemberMetaData().getFullFieldName()));
            }
        } else {
            // Class of the field will have its own table
            memberTable = storeMgr.getDatastoreClass(mapping.getType(), clr);
        }
        DiscriminatorMetaData dismd = memberTable.getDiscriminatorMetaData();
        DiscriminatorMapping discMapping = (DiscriminatorMapping) memberTable.getSurrogateMapping(SurrogateColumnType.DISCRIMINATOR, false);
        if (discMapping != null) {
            SQLTable targetSqlTbl = null;
            if (mapping.getTable() != memberTable) {
                // FK is on source table so inner join to target table (holding the discriminator)
                targetSqlTbl = stmt.getTable(memberTable, null);
                if (targetSqlTbl == null) {
                    targetSqlTbl = stmt.join(JoinType.INNER_JOIN, getSQLTable(), mapping, memberTable, null, memberTable.getIdMapping(), null, null);
                }
            } else {
                // FK is on target side and already joined
                targetSqlTbl = SQLStatementHelper.getSQLTableForMappingOfTable(stmt, getSQLTable(), discMapping);
            }
            // Add restrict to discriminator for the instanceOf type and subclasses
            SQLTable discSqlTbl = targetSqlTbl;
            BooleanExpression discExpr = null;
            if (!Modifier.isAbstract(type.getModifiers())) {
                discExpr = SQLStatementHelper.getExpressionForDiscriminatorForClass(stmt, type.getName(), dismd, discMapping, discSqlTbl, clr);
            }
            Iterator<String> subclassIter = storeMgr.getSubClassesForClass(type.getName(), true, clr).iterator();
            boolean multiplePossibles = false;
            while (subclassIter.hasNext()) {
                String subclassName = subclassIter.next();
                Class subclass = clr.classForName(subclassName);
                if (Modifier.isAbstract(subclass.getModifiers())) {
                    continue;
                }
                BooleanExpression discExprSub = SQLStatementHelper.getExpressionForDiscriminatorForClass(stmt, subclassName, dismd, discMapping, discSqlTbl, clr);
                if (discExpr != null) {
                    multiplePossibles = true;
                    discExpr = discExpr.ior(discExprSub);
                } else {
                    discExpr = discExprSub;
                }
            }
            if (multiplePossibles && discExpr != null) {
                discExpr.encloseInParentheses();
            }
            return ((not && discExpr != null) ? discExpr.not() : discExpr);
        }
        // No discriminator, so the following is likely incomplete.
        // Join to member table
        DatastoreClass table = null;
        if (memberCmd.getInheritanceMetaData().getStrategy() == InheritanceStrategy.SUBCLASS_TABLE) {
            // Field is a PC class that uses "subclass-table" inheritance strategy (and so has multiple possible tables to join to)
            AbstractClassMetaData[] cmds = storeMgr.getClassesManagingTableForClass(memberCmd, clr);
            if (cmds != null) {
                // TODO Allow for all possible tables. Can we do an OR of the tables ? How ?
                if (cmds.length > 1) {
                    NucleusLogger.QUERY.warn(Localiser.msg("037006", mapping.getMemberMetaData().getFullFieldName(), cmds[0].getFullClassName()));
                }
                table = storeMgr.getDatastoreClass(cmds[0].getFullClassName(), clr);
            } else {
                // No subclasses with tables to join to, so throw a user error
                throw new NucleusUserException(Localiser.msg("037005", mapping.getMemberMetaData().getFullFieldName()));
            }
        } else {
            // Class of the field will have its own table
            table = storeMgr.getDatastoreClass(mapping.getType(), clr);
        }
        if (table.managesClass(type.getName())) {
            // This type is managed in this table so must be an instance TODO Is this correct, what if member is using discrim?
            JavaTypeMapping m = exprFactory.getMappingForType(boolean.class, true);
            return exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, !not));
        }
        if (table == stmt.getPrimaryTable().getTable()) {
            // This is member table, so just need to restrict to the instanceof type now
            JavaTypeMapping m = exprFactory.getMappingForType(boolean.class, true);
            if (stmt instanceof SelectStatement) {
                SelectStatement selectStmt = (SelectStatement) stmt;
                if (selectStmt.getNumberOfUnions() == 0) {
                    // No UNIONs so just check the main statement and return according to whether it is allowed
                    Class mainCandidateCls = clr.classForName(stmt.getCandidateClassName());
                    if (type.isAssignableFrom(mainCandidateCls) == not) {
                        SQLExpression returnExpr = exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, false));
                        return (BooleanExpression) returnExpr;
                    }
                    SQLExpression returnExpr = exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, true));
                    return (BooleanExpression) returnExpr;
                }
                NucleusLogger.QUERY.warn("TYPE/INSTANCEOF operator for class=" + memberCmd.getFullClassName() + " on table=" + memberTable + " for type=" + instanceofClassName + " but there is no discriminator and using UNIONs. Any subsequent handling is likely incorrect TODO");
                // a). we have unions for the member, so restrict to just the applicable unions
                // Note that this is only really valid is wanting "a instanceof SUB1".
                // It fails when we want to do "a instanceof SUB1 || a instanceof SUB2"
                // TODO What if this "OP_IS" is in the SELECT clause??? Need to update QueryToSQLMapper.compileResult
                Class mainCandidateCls = clr.classForName(stmt.getCandidateClassName());
                if (type.isAssignableFrom(mainCandidateCls) == not) {
                    SQLExpression unionClauseExpr = exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, false));
                    stmt.whereAnd((BooleanExpression) unionClauseExpr, false);
                }
                List<SelectStatement> unionStmts = selectStmt.getUnions();
                for (SelectStatement unionStmt : unionStmts) {
                    Class unionCandidateCls = clr.classForName(unionStmt.getCandidateClassName());
                    if (type.isAssignableFrom(unionCandidateCls) == not) {
                        SQLExpression unionClauseExpr = exprFactory.newLiteral(unionStmt, m, true).eq(exprFactory.newLiteral(unionStmt, m, false));
                        // TODO Avoid using whereAnd
                        unionStmt.whereAnd((BooleanExpression) unionClauseExpr, false);
                    }
                }
                // Just return true since we applied the condition direct to the unions
                SQLExpression returnExpr = exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, true));
                return (BooleanExpression) returnExpr;
            }
            // b). The member table doesn't manage the instanceof type, so do inner join to
            // the table of the instanceof to impose the instanceof condition
            DatastoreClass instanceofTable = storeMgr.getDatastoreClass(type.getName(), clr);
            stmt.join(JoinType.INNER_JOIN, this.table, this.table.getTable().getIdMapping(), instanceofTable, null, instanceofTable.getIdMapping(), null, this.table.getGroupName());
            return exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, !not));
        }
        // Do inner join to this table to impose the instanceOf
        DatastoreClass instanceofTable = storeMgr.getDatastoreClass(type.getName(), clr);
        stmt.join(JoinType.INNER_JOIN, this.table, this.table.getTable().getIdMapping(), instanceofTable, null, instanceofTable.getIdMapping(), null, this.table.getGroupName());
        JavaTypeMapping m = exprFactory.getMappingForType(boolean.class, true);
        return exprFactory.newLiteral(stmt, m, true).eq(exprFactory.newLiteral(stmt, m, !not));
    } else {
        // TODO Implement instanceof for other types
        throw new NucleusException("Dont currently support " + this + " instanceof " + type.getName());
    }
}