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

Example 26 with Expression

use of org.datanucleus.query.expression.Expression in project datanucleus-core by datanucleus.

the class VarThisCompilationOptimiser method replaceVariableWithCandidateInExpression.

/**
 * Method that replaces any occurrence of the specified variable in the provided expression with the
 * candidate primary expression. Recurses to sub-expressions.
 * @param varName Variable name
 * @param expr The expression to update
 * @return Updated expression
 */
private Expression replaceVariableWithCandidateInExpression(String varName, Expression expr) {
    if (expr == null) {
        return null;
    }
    if (expr instanceof VariableExpression && ((VariableExpression) expr).getId().equals(varName)) {
        List<String> tuples = new ArrayList<String>();
        tuples.add(compilation.getCandidateAlias());
        Expression replExpr = new PrimaryExpression(tuples);
        replExpr.bind(compilation.getSymbolTable());
        return replExpr;
    } else if (expr instanceof DyadicExpression) {
        DyadicExpression dyExpr = (DyadicExpression) expr;
        if (dyExpr.getLeft() != null) {
            dyExpr.setLeft(replaceVariableWithCandidateInExpression(varName, dyExpr.getLeft()));
        }
        if (dyExpr.getRight() != null) {
            dyExpr.setRight(replaceVariableWithCandidateInExpression(varName, dyExpr.getRight()));
        }
    } else if (expr instanceof PrimaryExpression) {
        if (expr.getLeft() != null) {
            if (expr.getLeft() instanceof VariableExpression && ((VariableExpression) expr.getLeft()).getId().equals(varName)) {
                // Needs to be relative to candidate so just remove the "left"
                expr.setLeft(null);
            } else {
                expr.setLeft(replaceVariableWithCandidateInExpression(varName, expr.getLeft()));
            }
        }
    } else if (expr instanceof InvokeExpression) {
        InvokeExpression invokeExpr = (InvokeExpression) expr;
        if (invokeExpr.getLeft() != null) {
            invokeExpr.setLeft(replaceVariableWithCandidateInExpression(varName, invokeExpr.getLeft()));
        }
    // List<Expression> args = invokeExpr.getArguments(); // TODO Process Invoke args
    }
    // TODO More combinations
    return expr;
}

Example 27 with Expression

use of org.datanucleus.query.expression.Expression in project datanucleus-core by datanucleus.

the class JavaQueryInMemoryEvaluator method handleAggregates.

/**
 * Checks if there are aggregates and handle it.
 * @param resultSet The resultSet containing all elements
 * @return A list with aggregated elements
 */
private List handleAggregates(List resultSet) {
    final Expression[] grouping = compilation.getExprGrouping();
    Comparator c = new Comparator() {

        public int compare(Object arg0, Object arg1) {
            for (int i = 0; i < grouping.length; i++) {
                state.put(candidateAlias, arg0);
                Object a = grouping[i].evaluate(evaluator);
                state.put(candidateAlias, arg1);
                Object b = grouping[i].evaluate(evaluator);
                // Put any null values at the end
                if (a == null && b == null) {
                    return 0;
                } else if (a == null) {
                    return -1;
                } else if (b == null) {
                    return 1;
                } else {
                    int result = ((Comparable) a).compareTo(b);
                    if (result != 0) {
                        return result;
                    }
                }
            }
            return 0;
        }
    };
    List groups = new ArrayList();
    List group = new ArrayList();
    groups.add(group);
    for (int i = 0; i < resultSet.size(); i++) {
        if (i > 0) {
            if (c.compare(resultSet.get(i - 1), resultSet.get(i)) != 0) {
                group = new ArrayList();
                groups.add(group);
            }
        }
        group.add(resultSet.get(i));
    }
    List result = new ArrayList();
    Expression having = compilation.getExprHaving();
    if (having != null) {
        for (int i = 0; i < groups.size(); i++) {
            if (satisfiesHavingClause((List) groups.get(i))) {
                result.addAll((Collection) groups.get(i));
            }
        }
    } else {
        for (int i = 0; i < groups.size(); i++) {
            result.addAll((Collection) groups.get(i));
        }
    }
    return result;
}

Example 28 with Expression

use of org.datanucleus.query.expression.Expression in project datanucleus-api-jdo by datanucleus.

the class ComparableExpressionImpl method lt.

/* (non-Javadoc)
     * @see org.datanucleus.query.typesafe.Expression#lt(java.lang.Object)
     */
public BooleanExpression lt(T t) {
    Expression leftQueryExpr = queryExpr;
    Expression rightQueryExpr = new Literal(t);
    org.datanucleus.query.expression.Expression queryExpr = new DyadicExpression(leftQueryExpr, org.datanucleus.query.expression.Expression.OP_LT, rightQueryExpr);
    return new BooleanExpressionImpl(queryExpr);
}

Example 29 with Expression

use of org.datanucleus.query.expression.Expression in project datanucleus-api-jdo by datanucleus.

the class ComparableExpressionImpl method gt.

/* (non-Javadoc)
     * @see org.datanucleus.query.typesafe.Expression#gt(org.datanucleus.query.typesafe.ComparableExpression)
     */
public BooleanExpression gt(ComparableExpression expr) {
    Expression leftQueryExpr = queryExpr;
    Expression rightQueryExpr = ((ExpressionImpl) expr).getQueryExpression();
    org.datanucleus.query.expression.Expression queryExpr = new DyadicExpression(leftQueryExpr, org.datanucleus.query.expression.Expression.OP_GT, rightQueryExpr);
    return new BooleanExpressionImpl(queryExpr);
}

Example 30 with Expression

use of org.datanucleus.query.expression.Expression in project datanucleus-api-jdo by datanucleus.

the class ComparableExpressionImpl method gt.

/* (non-Javadoc)
     * @see org.datanucleus.query.typesafe.Expression#gt(java.lang.Object)
     */
public BooleanExpression gt(T t) {
    Expression leftQueryExpr = queryExpr;
    Expression rightQueryExpr = new Literal(t);
    org.datanucleus.query.expression.Expression queryExpr = new DyadicExpression(leftQueryExpr, org.datanucleus.query.expression.Expression.OP_GT, rightQueryExpr);
    return new BooleanExpressionImpl(queryExpr);
}