org.apache.calcite.rex.RexSubQuery.java Source code

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Here is the source code for org.apache.calcite.rex.RexSubQuery.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.apache.calcite.rex;

import org.apache.calcite.plan.RelOptUtil;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rel.type.RelDataTypeFactory;
import org.apache.calcite.rel.type.RelDataTypeField;
import org.apache.calcite.sql.SqlOperator;
import org.apache.calcite.sql.fun.SqlStdOperatorTable;
import org.apache.calcite.sql.type.SqlTypeName;

import com.google.common.collect.ImmutableList;

import java.util.List;

/**
 * Scalar expression that represents an IN, EXISTS or scalar sub-query.
 */
public class RexSubQuery extends RexCall {
    public final RelNode rel;

    private RexSubQuery(RelDataType type, SqlOperator op, ImmutableList<RexNode> operands, RelNode rel) {
        super(type, op, operands);
        this.rel = rel;
    }

    /** Creates an IN sub-query. */
    public static RexSubQuery in(RelNode rel, ImmutableList<RexNode> nodes) {
        assert rel.getRowType().getFieldCount() == nodes.size();
        final RelDataTypeFactory typeFactory = rel.getCluster().getTypeFactory();
        boolean nullable = false;
        for (RexNode node : nodes) {
            if (node.getType().isNullable()) {
                nullable = true;
            }
        }
        for (RelDataTypeField field : rel.getRowType().getFieldList()) {
            if (field.getType().isNullable()) {
                nullable = true;
            }
        }
        final RelDataType type = typeFactory
                .createTypeWithNullability(typeFactory.createSqlType(SqlTypeName.BOOLEAN), nullable);
        return new RexSubQuery(type, SqlStdOperatorTable.IN, nodes, rel);
    }

    /** Creates an EXISTS sub-query. */
    public static RexSubQuery exists(RelNode rel) {
        final RelDataTypeFactory typeFactory = rel.getCluster().getTypeFactory();
        final RelDataType type = typeFactory.createSqlType(SqlTypeName.BOOLEAN);
        return new RexSubQuery(type, SqlStdOperatorTable.EXISTS, ImmutableList.<RexNode>of(), rel);
    }

    /** Creates a scalar sub-query. */
    public static RexSubQuery scalar(RelNode rel) {
        final List<RelDataTypeField> fieldList = rel.getRowType().getFieldList();
        assert fieldList.size() == 1;
        final RelDataTypeFactory typeFactory = rel.getCluster().getTypeFactory();
        final RelDataType type = typeFactory.createTypeWithNullability(fieldList.get(0).getType(), true);
        return new RexSubQuery(type, SqlStdOperatorTable.SCALAR_QUERY, ImmutableList.<RexNode>of(), rel);
    }

    public <R> R accept(RexVisitor<R> visitor) {
        return visitor.visitSubQuery(this);
    }

    public <R, P> R accept(RexBiVisitor<R, P> visitor, P arg) {
        return visitor.visitSubQuery(this, arg);
    }

    @Override
    protected String computeDigest(boolean withType) {
        StringBuilder sb = new StringBuilder(op.getName());
        sb.append("(");
        for (RexNode operand : operands) {
            sb.append(operand.toString());
            sb.append(", ");
        }
        sb.append("{\n");
        sb.append(RelOptUtil.toString(rel));
        sb.append("})");
        return sb.toString();
    }

    @Override
    public RexSubQuery clone(RelDataType type, List<RexNode> operands) {
        return new RexSubQuery(type, getOperator(), ImmutableList.copyOf(operands), rel);
    }

    public RexSubQuery clone(RelNode rel) {
        return new RexSubQuery(type, getOperator(), operands, rel);
    }
}

// End RexSubQuery.java