SqlItemOperator.java
/*
* 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.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.type.SqlTypeUtil;
import java.util.Arrays;
import static org.apache.calcite.sql.type.NonNullableAccessors.getComponentTypeOrThrow;
import static org.apache.calcite.sql.validate.SqlNonNullableAccessors.getOperandLiteralValueOrThrow;
import static org.apache.calcite.util.Static.RESOURCE;
import static java.util.Objects.requireNonNull;
/**
* The item operator {@code [ ... ]}, used to access a given element of an
* array, map or struct. For example, {@code myArray[3]}, {@code "myMap['foo']"},
* {@code myStruct[2]} or {@code myStruct['fieldName']}.
*/
public class SqlItemOperator extends SqlSpecialOperator {
public final int offset;
public final boolean safe;
public SqlItemOperator(String name,
SqlSingleOperandTypeChecker operandTypeChecker,
int offset, boolean safe) {
super(name, SqlKind.ITEM, 100, true, null, null, operandTypeChecker);
this.offset = offset;
this.safe = safe;
}
@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(requireNonNull(left, "left").getParserPosition(),
requireNonNull(right, "right").getParserPosition(),
list.pos(ordinal))),
left,
right));
}
@Override public void unparse(
SqlWriter writer, SqlCall call, int leftPrec, int rightPrec) {
call.operand(0).unparse(writer, leftPrec, 0);
final SqlWriter.Frame frame = writer.startList("[", "]");
if (!this.getName().equals("ITEM")) {
final SqlWriter.Frame offsetFrame = writer.startFunCall(this.getName());
call.operand(1).unparse(writer, 0, 0);
writer.endFunCall(offsetFrame);
} else {
call.operand(1).unparse(writer, 0, 0);
}
writer.endList(frame);
}
@Override public SqlOperandCountRange getOperandCountRange() {
return SqlOperandCountRanges.of(2);
}
@Override public boolean checkOperandTypes(SqlCallBinding callBinding,
boolean throwOnFailure) {
final SqlNode left = callBinding.operand(0);
final SqlNode right = callBinding.operand(1);
if (!getOperandTypeChecker().checkSingleOperandType(callBinding, left, 0,
throwOnFailure)) {
return false;
}
final SqlSingleOperandTypeChecker checker = getChecker(callBinding);
if (!checker.checkSingleOperandType(callBinding, right, 0, throwOnFailure)) {
return false;
}
final RelDataType operandType = callBinding.getOperandType(0);
if (operandType.getSqlTypeName() != SqlTypeName.ROW) {
return true;
}
// For ROW types validate the index value (must be a constant).
RelDataType indexType = callBinding.getOperandType(1);
if (SqlTypeUtil.isString(indexType)) {
final String fieldName = getOperandLiteralValueOrThrow(callBinding, 1, String.class);
RelDataTypeField field = operandType.getField(fieldName, false, false);
if (field == null) {
if (throwOnFailure) {
throw callBinding.newValidationError(
RESOURCE.unknownRowField(fieldName, operandType.toString()));
} else {
return false;
}
}
} else if (SqlTypeUtil.isIntType(indexType)) {
Integer index = callBinding.getOperandLiteralValue(1, Integer.class);
if (index == null) {
if (throwOnFailure) {
throw callBinding.newValidationError(RESOURCE.illegalRowIndex());
} else {
return false;
}
}
if (index < 1 || index > operandType.getFieldCount()) {
if (throwOnFailure) {
throw callBinding.newValidationError(
RESOURCE.illegalRowIndexValue(index, operandType.getFieldCount()));
} else {
return false;
}
}
}
return true;
}
@Override public SqlSingleOperandTypeChecker getOperandTypeChecker() {
return (SqlSingleOperandTypeChecker)
requireNonNull(super.getOperandTypeChecker(), "operandTypeChecker");
}
private static SqlSingleOperandTypeChecker getChecker(SqlCallBinding callBinding) {
final RelDataType operandType = callBinding.getOperandType(0);
switch (operandType.getSqlTypeName()) {
case ARRAY:
return OperandTypes.family(SqlTypeFamily.INTEGER);
case MAP:
RelDataType keyType =
requireNonNull(operandType.getKeyType(), "operandType.getKeyType()");
SqlTypeName sqlTypeName = keyType.getSqlTypeName();
if (sqlTypeName == SqlTypeName.VARIANT) {
// Allow any key type to be used when the map keys have a VARIANT type
return OperandTypes.family(SqlTypeFamily.ANY);
}
return OperandTypes.family(
requireNonNull(sqlTypeName.getFamily(),
() -> "keyType.getSqlTypeName().getFamily() null, type is " + sqlTypeName));
case ROW:
case ANY:
case DYNAMIC_STAR:
case VARIANT:
return OperandTypes.family(SqlTypeFamily.INTEGER)
.or(OperandTypes.family(SqlTypeFamily.CHARACTER));
default:
throw callBinding.newValidationSignatureError();
}
}
@Override public String getAllowedSignatures(String name) {
if (name.equals("ITEM")) {
return "<ARRAY>[<INTEGER>]\n"
+ "<MAP>[<ANY>]\n"
+ "<ROW>[<CHARACTER>|<INTEGER>]\n"
+ "<VARIANT>[<ANY>]";
} else {
return "<ARRAY>[" + name + "(<INTEGER>)]";
}
}
@Override public RelDataType inferReturnType(SqlOperatorBinding opBinding) {
final RelDataTypeFactory typeFactory = opBinding.getTypeFactory();
final RelDataType operandType = opBinding.getOperandType(0);
switch (operandType.getSqlTypeName()) {
case VARIANT:
// Return type is always nullable VARIANT
return typeFactory.createTypeWithNullability(
operandType, true);
case ARRAY:
return typeFactory.createTypeWithNullability(
getComponentTypeOrThrow(operandType), true);
case MAP:
return typeFactory.createTypeWithNullability(
requireNonNull(operandType.getValueType(),
() -> "operandType.getValueType() is null for " + operandType),
true);
case ROW:
RelDataType fieldType;
RelDataType indexType = opBinding.getOperandType(1);
if (SqlTypeUtil.isString(indexType)) {
final String fieldName = getOperandLiteralValueOrThrow(opBinding, 1, String.class);
RelDataTypeField field = operandType.getField(fieldName, false, false);
if (field == null) {
throw new AssertionError("Cannot infer type of field '"
+ fieldName + "' within ROW type: " + operandType);
} else {
fieldType = field.getType();
}
} else if (SqlTypeUtil.isIntType(indexType)) {
Integer index = opBinding.getOperandLiteralValue(1, Integer.class);
if (index == null || index < 1 || index > operandType.getFieldCount()) {
throw new AssertionError("Cannot infer type of field at position "
+ index + " within ROW type: " + operandType);
} else {
fieldType = operandType.getFieldList().get(index - 1).getType(); // 1 indexed
}
} else {
throw new AssertionError("Unsupported field identifier type: '"
+ indexType + "'");
}
if (operandType.isNullable()) {
fieldType = typeFactory.enforceTypeWithNullability(fieldType, true);
}
return fieldType;
case ANY:
case DYNAMIC_STAR:
return typeFactory.createTypeWithNullability(
typeFactory.createSqlType(SqlTypeName.ANY), true);
default:
throw new AssertionError();
}
}
}