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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.sql.fun;
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.SqlCall;
import org.apache.calcite.sql.SqlCallBinding;
import org.apache.calcite.sql.SqlKind;
import org.apache.calcite.sql.SqlNode;
import org.apache.calcite.sql.SqlOperandCountRange;
import org.apache.calcite.sql.SqlOperatorBinding;
import org.apache.calcite.sql.SqlSpecialOperator;
import org.apache.calcite.sql.SqlUtil;
import org.apache.calcite.sql.SqlWriter;
import org.apache.calcite.sql.parser.SqlParserPos;
import org.apache.calcite.sql.type.OperandTypes;
import org.apache.calcite.sql.type.SqlOperandCountRanges;
import org.apache.calcite.sql.type.SqlSingleOperandTypeChecker;
import org.apache.calcite.sql.type.SqlTypeFamily;
import org.apache.calcite.sql.type.SqlTypeName;
import org.apache.calcite.sql.util.SqlBasicVisitor;
import org.apache.calcite.sql.util.SqlVisitor;
import org.apache.calcite.sql.validate.SqlValidator;
import org.apache.calcite.sql.validate.SqlValidatorScope;
import org.apache.calcite.sql.validate.SqlValidatorUtil;
import org.apache.calcite.util.Litmus;
import org.apache.calcite.util.Static;
import java.util.Arrays;
/**
* The dot operator {@code .}, used to access a field of a record. For example, {@code a.b}.
*
* This class was copied over from Calcite to fix the derived type. If the ROW is nullable force
* the accessed field to be nullable as well.
*/
public class SqlDotOperator extends SqlSpecialOperator {
SqlDotOperator() {
super("DOT", SqlKind.DOT, 100, true, null, null, null);
}
@Override
public ReduceResult reduceExpr(int ordinal, TokenSequence list) {
SqlNode left = list.node(ordinal - 1);
SqlNode right = list.node(ordinal + 1);
return new ReduceResult(
ordinal - 1,
ordinal + 2,
createCall(
SqlParserPos.sum(
Arrays.asList(
left.getParserPosition(),
right.getParserPosition(),
list.pos(ordinal))),
left,
right));
}
@Override
public void unparse(SqlWriter writer, SqlCall call, int leftPrec, int rightPrec) {
final SqlWriter.Frame frame = writer.startList(SqlWriter.FrameTypeEnum.IDENTIFIER);
call.operand(0).unparse(writer, leftPrec, 0);
writer.sep(".");
call.operand(1).unparse(writer, 0, 0);
writer.endList(frame);
}
@Override
public SqlOperandCountRange getOperandCountRange() {
return SqlOperandCountRanges.of(2);
}
@Override
public void acceptCall(
SqlVisitor visitor,
SqlCall call,
boolean onlyExpressions,
SqlBasicVisitor.ArgHandler argHandler) {
if (onlyExpressions) {
// Do not visit operands[1] -- it is not an expression.
argHandler.visitChild(visitor, call, 0, call.operand(0));
} else {
super.acceptCall(visitor, call, onlyExpressions, argHandler);
}
}
@Override
public RelDataType deriveType(SqlValidator validator, SqlValidatorScope scope, SqlCall call) {
final SqlNode operand = call.getOperandList().get(0);
final RelDataType nodeType = validator.deriveType(scope, operand);
assert nodeType != null;
if (!nodeType.isStruct()) {
throw SqlUtil.newContextException(
operand.getParserPosition(), Static.RESOURCE.incompatibleTypes());
}
final SqlNode fieldId = call.operand(1);
final String fieldName = fieldId.toString();
final RelDataTypeField field = nodeType.getField(fieldName, false, false);
if (field == null) {
throw SqlUtil.newContextException(
fieldId.getParserPosition(), Static.RESOURCE.unknownField(fieldName));
}
RelDataType type = field.getType();
if (nodeType.isNullable()) {
type = validator.getTypeFactory().createTypeWithNullability(type, true);
}
// Validate and determine coercibility and resulting collation
// name of binary operator if needed.
type = adjustType(validator, call, type);
SqlValidatorUtil.checkCharsetAndCollateConsistentIfCharType(type);
return type;
}
public void validateCall(
SqlCall call,
SqlValidator validator,
SqlValidatorScope scope,
SqlValidatorScope operandScope) {
assert call.getOperator() == this;
// Do not visit call.getOperandList().get(1) here.
// call.getOperandList().get(1) will be validated when deriveType() is called.
call.getOperandList().get(0).validateExpr(validator, operandScope);
}
@Override
public boolean checkOperandTypes(SqlCallBinding callBinding, boolean throwOnFailure) {
final SqlNode left = callBinding.operand(0);
final SqlNode right = callBinding.operand(1);
final RelDataType type =
callBinding.getValidator().deriveType(callBinding.getScope(), left);
if (type.getSqlTypeName() != SqlTypeName.ROW) {
return false;
} else if (type.getSqlIdentifier().isStar()) {
return false;
}
final RelDataType operandType = callBinding.getOperandType(0);
final SqlSingleOperandTypeChecker checker = getChecker(operandType);
// Actually operand0 always comes from parsing the SqlIdentifier, so there
// is no need to make implicit type coercion.
return checker.checkSingleOperandType(callBinding, right, 0, throwOnFailure);
}
private SqlSingleOperandTypeChecker getChecker(RelDataType operandType) {
switch (operandType.getSqlTypeName()) {
case ROW:
return OperandTypes.family(SqlTypeFamily.STRING);
default:
throw new AssertionError(operandType.getSqlTypeName());
}
}
@Override
public boolean validRexOperands(final int count, final Litmus litmus) {
return litmus.fail("DOT is valid only for SqlCall not for RexCall");
}
@Override
public String getAllowedSignatures(String name) {
return ".";
}
@Override
public RelDataType inferReturnType(SqlOperatorBinding opBinding) {
final RelDataTypeFactory typeFactory = opBinding.getTypeFactory();
final RelDataType recordType = opBinding.getOperandType(0);
switch (recordType.getSqlTypeName()) {
case ROW:
final String fieldName = opBinding.getOperandLiteralValue(1, String.class);
final RelDataType type =
opBinding.getOperandType(0).getField(fieldName, false, false).getType();
if (recordType.isNullable()) {
return typeFactory.createTypeWithNullability(type, true);
} else {
return type;
}
default:
throw new AssertionError();
}
}
}