src/main/java/org/eigenbase/sql/SqlSetOperator.java

/*
// Licensed to Julian Hyde under one or more contributor license
// agreements. See the NOTICE file distributed with this work for
// additional information regarding copyright ownership.
//
// Julian Hyde licenses this file to you under the Apache License,
// Version 2.0 (the "License"); you may not use this file except in
// compliance with the License. You may obtain a copy of the License at:
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
*/
package org.eigenbase.sql;

import org.eigenbase.sql.type.*;
import org.eigenbase.sql.validate.*;


/**
 * SqlSetOperator represents a relational set theory operator (UNION, INTERSECT,
 * MINUS). These are binary operators, but with an extra boolean attribute
 * tacked on for whether to remove duplicates (e.g. UNION ALL does not remove
 * duplicates).
 *
 * @author John V. Sichi
 * @version $Id$
 */
public class SqlSetOperator
    extends SqlBinaryOperator
{
    //~ Instance fields --------------------------------------------------------

    private final boolean all;

    //~ Constructors -----------------------------------------------------------

    public SqlSetOperator(
        String name,
        SqlKind kind,
        int prec,
        boolean all)
    {
        super(
            name,
            kind,
            prec,
            true,
            SqlTypeStrategies.rtiLeastRestrictive,
            null,
            SqlTypeStrategies.otcSetop);
        this.all = all;
    }

    public SqlSetOperator(
        String name,
        SqlKind kind,
        int prec,
        boolean all,
        SqlReturnTypeInference returnTypeInference,
        SqlOperandTypeInference operandTypeInference,
        SqlOperandTypeChecker operandTypeChecker)
    {
        super(
            name,
            kind,
            prec,
            true,
            returnTypeInference,
            operandTypeInference,
            operandTypeChecker);
        this.all = all;
    }

    //~ Methods ----------------------------------------------------------------

    public boolean isAll()
    {
        return all;
    }

    public boolean isDistinct()
    {
        return !all;
    }

    public void validateCall(
        SqlCall call,
        SqlValidator validator,
        SqlValidatorScope scope,
        SqlValidatorScope operandScope)
    {
        validator.validateQuery(call, operandScope);
    }
}

// End SqlSetOperator.java