Examples with DyadicExpression org.datanucleus.store.query.expression.DyadicExpression used on opensource projects

Example 6 with DyadicExpression

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

the class QueryToSQLMapper method processInvokeExpression.

/**
 * Internal method to handle the processing of an InvokeExpression.
 * @param expr The InvokeExpression
 * @param invokedSqlExpr The SQLExpression that we are invoking the method on.
 * @return The resultant SQLExpression
 */
protected SQLExpression processInvokeExpression(InvokeExpression expr, SQLExpression invokedSqlExpr) {
    if (invokedSqlExpr instanceof NullLiteral) {
        // We cannot invoke anything on a null TODO Handle this "NPE"
        NucleusLogger.QUERY.warn("Compilation of InvokeExpression needs to invoke method \"" + expr.getOperation() + "\" on " + invokedSqlExpr + " but not possible");
    }
    String operation = expr.getOperation();
    if (invokedSqlExpr instanceof MapExpression && operation.equals("contains") && compilation.getQueryLanguage().equalsIgnoreCase(Query.LANGUAGE_JPQL)) {
        // JPQL "MEMBER OF" will be passed through from generic compilation as "contains" since we don't know types at that point
        operation = "containsValue";
    }
    // Process the arguments for invoking
    List args = expr.getArguments();
    List sqlExprArgs = null;
    if (args != null) {
        sqlExprArgs = new ArrayList<SQLExpression>();
        Iterator<Expression> iter = args.iterator();
        while (iter.hasNext()) {
            Expression argExpr = iter.next();
            if (argExpr instanceof PrimaryExpression) {
                processPrimaryExpression((PrimaryExpression) argExpr);
                SQLExpression argSqlExpr = stack.pop();
                if (compileComponent == CompilationComponent.RESULT && operation.equalsIgnoreCase("count") && stmt.getNumberOfTableGroups() > 1) {
                    if (argSqlExpr.getSQLTable() == stmt.getPrimaryTable() && argSqlExpr.getJavaTypeMapping() == stmt.getPrimaryTable().getTable().getIdMapping()) {
                        // Result with "count(this)" and joins to other groups, so enforce distinct
                        argSqlExpr.distinct();
                    }
                }
                sqlExprArgs.add(argSqlExpr);
            } else if (argExpr instanceof ParameterExpression) {
                processParameterExpression((ParameterExpression) argExpr);
                sqlExprArgs.add(stack.pop());
            } else if (argExpr instanceof InvokeExpression) {
                processInvokeExpression((InvokeExpression) argExpr);
                sqlExprArgs.add(stack.pop());
            } else if (argExpr instanceof Literal) {
                processLiteral((Literal) argExpr);
                sqlExprArgs.add(stack.pop());
            } else if (argExpr instanceof DyadicExpression) {
                // Evaluate using this evaluator
                argExpr.evaluate(this);
                sqlExprArgs.add(stack.pop());
            } else if (argExpr instanceof VariableExpression) {
                processVariableExpression((VariableExpression) argExpr);
                sqlExprArgs.add(stack.pop());
            } else if (argExpr instanceof CaseExpression) {
                processCaseExpression((CaseExpression) argExpr);
                sqlExprArgs.add(stack.pop());
            } else {
                throw new NucleusException("Dont currently support invoke expression argument " + argExpr);
            }
        }
        if (operation.equals("INDEX")) {
            // Special case of index expression
            List<Expression> indexArgs = expr.getArguments();
            if (indexArgs == null || indexArgs.size() > 1) {
                throw new NucleusException("Can only use INDEX with single argument");
            }
            PrimaryExpression indexExpr = (PrimaryExpression) indexArgs.get(0);
            String joinAlias = indexExpr.getId();
            String collExprName = joinAlias;
            if (explicitJoinPrimaryByAlias != null) {
                collExprName = explicitJoinPrimaryByAlias.get(joinAlias);
                if (collExprName == null) {
                    throw new NucleusException("Unable to locate primary expression for alias " + joinAlias);
                }
            }
            // Find an expression for the collection field
            List<String> tuples = new ArrayList<>();
            StringTokenizer primTokenizer = new StringTokenizer(collExprName, ".");
            while (primTokenizer.hasMoreTokens()) {
                String token = primTokenizer.nextToken();
                tuples.add(token);
            }
            PrimaryExpression collPrimExpr = new PrimaryExpression(tuples);
            processPrimaryExpression(collPrimExpr);
            SQLExpression collSqlExpr = stack.pop();
            sqlExprArgs.add(collSqlExpr);
        }
    }
    // Invoke the method
    SQLExpression sqlExpr = null;
    if (invokedSqlExpr instanceof org.datanucleus.store.rdbms.sql.expression.SubqueryExpression) {
        if (operation.equalsIgnoreCase("isEmpty")) {
            // Special case of {subquery}.isEmpty(), equates to "NOT EXISTS (subquery)"
            org.datanucleus.store.rdbms.sql.expression.SubqueryExpression subquerySqlExpr = (org.datanucleus.store.rdbms.sql.expression.SubqueryExpression) invokedSqlExpr;
            SQLStatement subStmt = subquerySqlExpr.getSubqueryStatement();
            SQLExpression subqueryNotExistsExpr = new BooleanSubqueryExpression(stmt, "EXISTS", subStmt).not();
            stack.push(subqueryNotExistsExpr);
            return subqueryNotExistsExpr;
        } else if (operation.equalsIgnoreCase("size")) {
            // {subquery}.size() should simply be changed to have a subquery of "SELECT COUNT(*) FROM ..."
            throw new NucleusUserException("Attempt to invoke method `" + operation + "` on Subquery. This is not supported. Change the subquery to return COUNT() instead.");
        }
        throw new NucleusUserException("Attempt to invoke method `" + operation + "` on Subquery. This is not supported");
    }
    if (invokedSqlExpr != null) {
        sqlExpr = invokedSqlExpr.invoke(operation, sqlExprArgs);
    } else {
        sqlExpr = exprFactory.invokeMethod(stmt, null, operation, null, sqlExprArgs);
    }
    stack.push(sqlExpr);
    return sqlExpr;
}