/*
* 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.phoenix.parse;
import java.sql.SQLException;
import java.util.List;
import org.apache.phoenix.compile.StatementContext;
import org.apache.phoenix.expression.Expression;
import org.apache.phoenix.expression.function.RoundDateExpression;
import org.apache.phoenix.expression.function.RoundDecimalExpression;
import org.apache.phoenix.expression.function.RoundFunction;
import org.apache.phoenix.expression.function.RoundTimestampExpression;
import org.apache.phoenix.schema.PDataType;
import org.apache.phoenix.schema.TypeMismatchException;
/**
*
* Parse node corresponding to {@link RoundFunction}.
* It also acts as a factory for creating the right kind of
* round expression according to the data type of the
* first child.
*
*
* @since 3.0.0
*/
public class RoundParseNode extends FunctionParseNode {
RoundParseNode(String name, List<ParseNode> children, BuiltInFunctionInfo info) {
super(name, children, info);
}
@Override
public Expression create(List<Expression> children, StatementContext context) throws SQLException {
return getRoundExpression(children);
}
public static Expression getRoundExpression(List<Expression> children) throws SQLException {
final Expression firstChild = children.get(0);
final PDataType firstChildDataType = firstChild.getDataType();
if(firstChildDataType.isCoercibleTo(PDataType.DATE)) {
return RoundDateExpression.create(children);
} else if (firstChildDataType.isCoercibleTo(PDataType.TIMESTAMP)) {
return RoundTimestampExpression.create(children);
} else if(firstChildDataType.isCoercibleTo(PDataType.DECIMAL)) {
return RoundDecimalExpression.create(children);
} else {
throw TypeMismatchException.newException(firstChildDataType, "1");
}
}
/**
* When rounding off decimals, user need not specify the scale. In such cases,
* we need to prevent the function from getting evaluated as null. This is really
* a hack. A better way would have been if {@link org.apache.phoenix.parse.FunctionParseNode.BuiltInFunctionInfo} provided a
* way of associating default values for each permissible data type.
* Something like: @ Argument(allowedTypes={PDataType.VARCHAR, PDataType.INTEGER}, defaultValues = {"null", "1"} isConstant=true)
* Till then, this will have to do.
*/
@Override
public boolean evalToNullIfParamIsNull(StatementContext context, int index) throws SQLException {
return index == 0;
}
}