com.hazelcast.org.apache.calcite.sql.fun.SqlMultisetQueryConstructor Maven / Gradle / Ivy

/*
 * 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 com.hazelcast.org.apache.calcite.sql.fun;

import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.rel.type.RelDataTypeFactory;
import com.hazelcast.org.apache.calcite.sql.SqlCall;
import com.hazelcast.org.apache.calcite.sql.SqlCallBinding;
import com.hazelcast.org.apache.calcite.sql.SqlKind;
import com.hazelcast.org.apache.calcite.sql.SqlOperatorBinding;
import com.hazelcast.org.apache.calcite.sql.SqlSelect;
import com.hazelcast.org.apache.calcite.sql.SqlSpecialOperator;
import com.hazelcast.org.apache.calcite.sql.SqlWriter;
import com.hazelcast.org.apache.calcite.sql.type.OperandTypes;
import com.hazelcast.org.apache.calcite.sql.type.ReturnTypes;
import com.hazelcast.org.apache.calcite.sql.type.SqlTypeUtil;
import com.hazelcast.org.apache.calcite.sql.validate.SqlValidator;
import com.hazelcast.org.apache.calcite.sql.validate.SqlValidatorNamespace;
import com.hazelcast.org.apache.calcite.sql.validate.SqlValidatorScope;

import java.util.List;

import static com.hazelcast.org.apache.calcite.util.Static.RESOURCE;

/**
 * Definition of the SQL:2003 standard MULTISET query constructor, 
 * MULTISET (<query>).
 *
 * @see SqlMultisetValueConstructor
 */
public class SqlMultisetQueryConstructor extends SqlSpecialOperator {
  //~ Constructors -----------------------------------------------------------

  public SqlMultisetQueryConstructor() {
    this("MULTISET", SqlKind.MULTISET_QUERY_CONSTRUCTOR);
  }

  protected SqlMultisetQueryConstructor(String name, SqlKind kind) {
    super(
        name,
        kind, MDX_PRECEDENCE,
        false,
        ReturnTypes.ARG0,
        null,
        OperandTypes.VARIADIC);
  }

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

  public RelDataType inferReturnType(
      SqlOperatorBinding opBinding) {
    RelDataType type =
        getComponentType(
            opBinding.getTypeFactory(),
            opBinding.collectOperandTypes());
    if (null == type) {
      return null;
    }
    return SqlTypeUtil.createMultisetType(
        opBinding.getTypeFactory(),
        type,
        false);
  }

  private RelDataType getComponentType(
      RelDataTypeFactory typeFactory,
      List argTypes) {
    return typeFactory.leastRestrictive(argTypes);
  }

  public boolean checkOperandTypes(
      SqlCallBinding callBinding,
      boolean throwOnFailure) {
    final List argTypes =
        SqlTypeUtil.deriveAndCollectTypes(
            callBinding.getValidator(),
            callBinding.getScope(),
            callBinding.operands());
    final RelDataType componentType =
        getComponentType(
            callBinding.getTypeFactory(),
            argTypes);
    if (null == componentType) {
      if (throwOnFailure) {
        throw callBinding.newValidationError(RESOURCE.needSameTypeParameter());
      }
      return false;
    }
    return true;
  }

  public RelDataType deriveType(
      SqlValidator validator,
      SqlValidatorScope scope,
      SqlCall call) {
    SqlSelect subSelect = call.operand(0);
    subSelect.validateExpr(validator, scope);
    SqlValidatorNamespace ns = validator.getNamespace(subSelect);
    assert null != ns.getRowType();
    return SqlTypeUtil.createMultisetType(
        validator.getTypeFactory(),
        ns.getRowType(),
        false);
  }

  public void unparse(
      SqlWriter writer,
      SqlCall call,
      int leftPrec,
      int rightPrec) {
    writer.keyword(getName());
    final SqlWriter.Frame frame = writer.startList("(", ")");
    assert call.operandCount() == 1;
    call.operand(0).unparse(writer, leftPrec, rightPrec);
    writer.endList(frame);
  }

  public boolean argumentMustBeScalar(int ordinal) {
    return false;
  }
}