/*
* 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.eigenbase.rex;
import java.math.*;
import java.util.*;
import org.eigenbase.rel.*;
import org.eigenbase.reltype.*;
import org.eigenbase.sql.*;
import org.eigenbase.sql.SqlIntervalQualifier.TimeUnit;
import org.eigenbase.sql.fun.*;
import org.eigenbase.sql.type.*;
import org.eigenbase.util.*;
import org.eigenbase.util14.DateTimeUtil;
import net.hydromatic.avatica.ByteString;
import net.hydromatic.optiq.runtime.Spaces;
import net.hydromatic.optiq.runtime.SqlFunctions;
import com.google.common.collect.ImmutableList;
/**
* Factory for row expressions.
*
* <p>Some common literal values (NULL, TRUE, FALSE, 0, 1, '') are cached.</p>
*/
public class RexBuilder {
/**
* Special operator that accesses an unadvertised field of an input record.
* This operator cannot be used in SQL queries; it is introduced temporarily
* during sql-to-rel translation, then replaced during the process that
* trims unwanted fields.
*/
public static final SqlSpecialOperator GET_OPERATOR =
new SqlSpecialOperator("_get", SqlKind.OTHER_FUNCTION);
//~ Instance fields --------------------------------------------------------
protected final RelDataTypeFactory typeFactory;
private final RexLiteral booleanTrue;
private final RexLiteral booleanFalse;
private final RexLiteral charEmpty;
private final RexLiteral constantNull;
private final SqlStdOperatorTable opTab = SqlStdOperatorTable.instance();
//~ Constructors -----------------------------------------------------------
/**
* Creates a RexBuilder.
*
* @param typeFactory Type factory
*/
public RexBuilder(RelDataTypeFactory typeFactory) {
this.typeFactory = typeFactory;
this.booleanTrue =
makeLiteral(
Boolean.TRUE,
typeFactory.createSqlType(SqlTypeName.BOOLEAN),
SqlTypeName.BOOLEAN);
this.booleanFalse =
makeLiteral(
Boolean.FALSE,
typeFactory.createSqlType(SqlTypeName.BOOLEAN),
SqlTypeName.BOOLEAN);
this.charEmpty =
makeLiteral(
new NlsString("", null, null),
typeFactory.createSqlType(SqlTypeName.CHAR, 0),
SqlTypeName.CHAR);
this.constantNull =
makeLiteral(
null,
typeFactory.createSqlType(SqlTypeName.NULL),
SqlTypeName.NULL);
}
//~ Methods ----------------------------------------------------------------
/**
* Returns this RexBuilder's type factory
*
* @return type factory
*/
public RelDataTypeFactory getTypeFactory() {
return typeFactory;
}
/**
* Returns this RexBuilder's operator table
*
* @return operator table
*/
public SqlStdOperatorTable getOpTab() {
return opTab;
}
/**
* Creates an expression accessing a given named field from a record.
*
* <p>NOTE: Be careful choosing the value of {@code caseSensitive}.
* If the field name was supplied by an end-user (e.g. as a column alias in
* SQL), use your session's case-sensitivity setting.
* Only hard-code {@code true} if you are sure that the field name is
* internally generated.
* Hard-coding {@code false} is almost certainly wrong.</p>
*
* @param expr Expression yielding a record
* @param fieldName Name of field in record
* @param caseSensitive Whether match is case-sensitive
* @return Expression accessing a given named field
*/
public RexNode makeFieldAccess(RexNode expr, String fieldName,
boolean caseSensitive) {
final RelDataType type = expr.getType();
final RelDataTypeField field = type.getField(fieldName, caseSensitive);
if (field == null) {
throw Util.newInternal(
"Type '" + type + "' has no field '"
+ fieldName + "'");
}
return makeFieldAccessInternal(expr, field);
}
/**
* Creates an expression accessing a field with a given ordinal from a
* record.
*
* @param expr Expression yielding a record
* @param i Ordinal of field
* @return Expression accessing given field
*/
public RexNode makeFieldAccess(
RexNode expr,
int i) {
final RelDataType type = expr.getType();
final List<RelDataTypeField> fields = type.getFieldList();
if ((i < 0) || (i >= fields.size())) {
throw Util.newInternal(
"Field ordinal " + i + " is invalid for "
+ " type '" + type + "'");
}
return makeFieldAccessInternal(expr, fields.get(i));
}
/**
* Creates an expression accessing a given field from a record.
*
* @param expr Expression yielding a record
* @param field Field
* @return Expression accessing given field
*/
private RexNode makeFieldAccessInternal(
RexNode expr,
final RelDataTypeField field) {
if (expr instanceof RexRangeRef) {
RexRangeRef range = (RexRangeRef) expr;
if (field.getIndex() < 0) {
return makeCall(
field.getType(),
GET_OPERATOR,
ImmutableList.of(
expr,
makeLiteral(field.getName())));
}
return new RexInputRef(
range.getOffset() + field.getIndex(),
field.getType());
}
return new RexFieldAccess(expr, field);
}
/**
* Creates a call with a list of arguments and a predetermined type.
*/
public RexNode makeCall(
RelDataType returnType,
SqlOperator op,
List<RexNode> exprs) {
return new RexCall(returnType, op, exprs);
}
/**
* Creates a call with an array of arguments.
*
* <p>If you already know the return type of the call, then
* {@link #makeCall(org.eigenbase.reltype.RelDataType, org.eigenbase.sql.SqlOperator, java.util.List)}
* is preferred.</p>
*/
public RexNode makeCall(
SqlOperator op,
List<? extends RexNode> exprs) {
final RelDataType type = deriveReturnType(op, exprs);
return new RexCall(type, op, exprs);
}
/**
* Creates a call with a list of arguments.
*
* <p>Equivalent to <code>makeCall(op, exprList.toArray(new
* RexNode[exprList.size()]))</code>.
*/
public final RexNode makeCall(
SqlOperator op,
RexNode... exprs) {
return makeCall(op, ImmutableList.copyOf(exprs));
}
/**
* Derives the return type of a call to an operator.
*
* @param op the operator being called
* @param exprs actual operands
* @return derived type
*/
public RelDataType deriveReturnType(
SqlOperator op,
List<? extends RexNode> exprs) {
return op.inferReturnType(new RexCallBinding(typeFactory, op, exprs));
}
/**
* Creates a reference to an aggregate call, checking for repeated calls.
*
* <p>Argument types help to optimize for repeated aggregates.
* For instance count(42) is equivalent to count(*).</p>
*
* @param aggCall aggregate call to be added
* @param groupCount number of groups in the aggregate relation
* @param aggCalls destination list of aggregate calls
* @param aggCallMapping the dictionary of already added calls
* @param aggArgTypes Argument types, not null
* @return Rex expression for the given aggregate call
*/
public RexNode addAggCall(
AggregateCall aggCall,
int groupCount,
List<AggregateCall> aggCalls,
Map<AggregateCall, RexNode> aggCallMapping,
final List<RelDataType> aggArgTypes) {
if (aggCall.getAggregation() instanceof SqlCountAggFunction
&& !aggCall.isDistinct()) {
final List<Integer> args = aggCall.getArgList();
final List<Integer> nullableArgs = nullableArgs(args, aggArgTypes);
if (!nullableArgs.equals(args)) {
aggCall = aggCall.copy(nullableArgs);
}
}
RexNode rex = aggCallMapping.get(aggCall);
if (rex == null) {
int index = aggCalls.size() + groupCount;
aggCalls.add(aggCall);
rex = makeInputRef(aggCall.getType(), index);
aggCallMapping.put(aggCall, rex);
}
return rex;
}
private static List<Integer> nullableArgs(List<Integer> list0,
List<RelDataType> types) {
final List<Integer> list = new ArrayList<Integer>();
for (Pair<Integer, RelDataType> pair : Pair.zip(list0, types)) {
if (pair.right.isNullable()) {
list.add(pair.left);
}
}
return list;
}
/**
* Creates a call to a windowed agg.
*/
public RexNode makeOver(
RelDataType type,
SqlAggFunction operator,
List<RexNode> exprs,
List<RexNode> partitionKeys,
ImmutableList<RexFieldCollation> orderKeys,
RexWindowBound lowerBound,
RexWindowBound upperBound,
boolean physical,
boolean allowPartial,
boolean nullWhenCountZero) {
assert operator != null;
assert exprs != null;
assert partitionKeys != null;
assert orderKeys != null;
final RexWindow window =
makeWindow(
partitionKeys,
orderKeys,
lowerBound,
upperBound,
physical);
final RexOver over = new RexOver(type, operator, exprs, window);
RexNode result = over;
// This should be correct but need time to go over test results.
// Also want to look at combing with section below.
if (nullWhenCountZero) {
final RelDataType bigintType = getTypeFactory().createSqlType(
SqlTypeName.BIGINT);
result = makeCall(
SqlStdOperatorTable.CASE,
makeCall(
SqlStdOperatorTable.GREATER_THAN,
new RexOver(
bigintType,
SqlStdOperatorTable.COUNT,
exprs,
window),
makeLiteral(
BigDecimal.ZERO,
bigintType,
SqlTypeName.DECIMAL)),
ensureType(type, // SUM0 is non-nullable, thus need a cast
new RexOver(typeFactory.createTypeWithNullability(type, false),
operator, exprs, window),
false),
makeCast(type, constantNull()));
}
if (!allowPartial) {
Util.permAssert(physical, "DISALLOW PARTIAL over RANGE");
final RelDataType bigintType = getTypeFactory().createSqlType(
SqlTypeName.BIGINT);
// todo: read bound
result =
makeCall(
SqlStdOperatorTable.CASE,
makeCall(
SqlStdOperatorTable.GREATER_THAN_OR_EQUAL,
new RexOver(
bigintType,
SqlStdOperatorTable.COUNT,
ImmutableList.<RexNode>of(),
window),
makeLiteral(
BigDecimal.valueOf(2),
bigintType,
SqlTypeName.DECIMAL)),
result,
constantNull);
}
return result;
}
/**
* Creates a window specification.
*
* @param partitionKeys Partition keys
* @param orderKeys Order keys
* @param lowerBound Lower bound
* @param upperBound Upper bound
* @param isRows Whether physical. True if row-based, false if
* range-based
* @return window specification
*/
public RexWindow makeWindow(
List<RexNode> partitionKeys,
ImmutableList<RexFieldCollation> orderKeys,
RexWindowBound lowerBound,
RexWindowBound upperBound,
boolean isRows) {
return new RexWindow(
partitionKeys,
orderKeys,
lowerBound,
upperBound,
isRows);
}
/**
* Creates a constant for the SQL <code>NULL</code> value.
*/
public RexLiteral constantNull() {
return constantNull;
}
/**
* Creates an expression referencing a correlation variable.
*
* @param type Type of variable
* @param name Name of variable
* @return Correlation variable
*/
public RexNode makeCorrel(
RelDataType type,
String name) {
return new RexCorrelVariable(name, type);
}
/**
* Creates an invocation of the NEW operator.
*
* @param type Type to be instantiated
* @param exprs Arguments to NEW operator
* @return Expression invoking NEW operator
*/
public RexNode makeNewInvocation(
RelDataType type,
List<RexNode> exprs) {
return new RexCall(
type,
SqlStdOperatorTable.NEW,
exprs);
}
/**
* Creates a call to the CAST operator, expanding if possible.
*
* @param type Type to cast to
* @param exp Expression being cast
* @return Call to CAST operator
*/
public RexNode makeCast(
RelDataType type,
RexNode exp) {
final SqlTypeName sqlType = type.getSqlTypeName();
if (exp instanceof RexLiteral) {
RexLiteral literal = (RexLiteral) exp;
Comparable value = literal.getValue();
if (RexLiteral.valueMatchesType(value, sqlType, false)
&& (!(value instanceof NlsString)
|| (type.getPrecision()
>= ((NlsString) value).getValue().length()))
&& (!(value instanceof ByteString)
|| (type.getPrecision()
>= ((ByteString) value).length()))) {
switch (literal.getTypeName()) {
case CHAR:
if (value instanceof NlsString) {
value = ((NlsString) value).rtrim();
}
break;
case TIMESTAMP:
case TIME:
final Calendar calendar = (Calendar) value;
int scale = type.getScale();
if (scale == RelDataType.SCALE_NOT_SPECIFIED) {
scale = 0;
}
calendar.setTimeInMillis(
SqlFunctions.round(
calendar.getTimeInMillis(),
SqlFunctions.powerX(10, 3 - scale)));
break;
case INTERVAL_DAY_TIME:
BigDecimal value2 = (BigDecimal) value;
final long multiplier =
literal.getType().getIntervalQualifier().getStartUnit()
.multiplier;
SqlTypeName typeName = type.getSqlTypeName();
// Not all types are allowed for literals
switch (typeName) {
case INTEGER:
typeName = SqlTypeName.BIGINT;
}
return makeLiteral(
value2.divide(
BigDecimal.valueOf(multiplier), 0,
BigDecimal.ROUND_HALF_DOWN),
type, typeName);
}
return makeLiteral(value, type, literal.getTypeName());
}
} else if (SqlTypeUtil.isInterval(type)
&& SqlTypeUtil.isExactNumeric(exp.getType())) {
return makeCastExactToInterval(type, exp);
} else if (SqlTypeUtil.isExactNumeric(type)
&& SqlTypeUtil.isInterval(exp.getType())) {
return makeCastIntervalToExact(type, exp);
} else if (sqlType == SqlTypeName.BOOLEAN
&& SqlTypeUtil.isExactNumeric(exp.getType())) {
return makeCastExactToBoolean(type, exp);
} else if (exp.getType().getSqlTypeName() == SqlTypeName.BOOLEAN
&& SqlTypeUtil.isExactNumeric(type)) {
return makeCastBooleanToExact(type, exp);
}
return makeAbstractCast(type, exp);
}
private RexNode makeCastExactToBoolean(RelDataType toType, RexNode exp) {
return makeCall(
toType,
SqlStdOperatorTable.NOT_EQUALS,
ImmutableList.of(exp, makeZeroLiteral(exp.getType())));
}
private RexNode makeCastBooleanToExact(RelDataType toType, RexNode exp) {
final RexNode casted = makeCall(
SqlStdOperatorTable.CASE,
exp,
makeExactLiteral(BigDecimal.ONE, toType),
makeZeroLiteral(toType));
if (!exp.getType().isNullable()) {
return casted;
}
return makeCall(
toType,
SqlStdOperatorTable.CASE,
ImmutableList.<RexNode>of(
makeCall(SqlStdOperatorTable.IS_NOT_NULL, exp),
casted,
makeNullLiteral(toType.getSqlTypeName())));
}
private RexNode makeCastIntervalToExact(RelDataType toType, RexNode exp) {
IntervalSqlType intervalType = (IntervalSqlType) exp.getType();
TimeUnit endUnit = intervalType.getIntervalQualifier().getEndUnit();
if (endUnit == null) {
endUnit = intervalType.getIntervalQualifier().getStartUnit();
}
int scale = 0;
if (endUnit == TimeUnit.SECOND) {
scale = Math.min(
intervalType.getIntervalQualifier()
.getFractionalSecondPrecision(typeFactory.getTypeSystem()),
3);
}
BigDecimal multiplier = BigDecimal.valueOf(endUnit.multiplier)
.divide(BigDecimal.TEN.pow(scale));
RexNode value = decodeIntervalOrDecimal(exp);
if (multiplier.longValue() != 1) {
value = makeCall(
SqlStdOperatorTable.DIVIDE_INTEGER,
value, makeBigintLiteral(multiplier));
}
if (scale > 0) {
RelDataType decimalType =
getTypeFactory().createSqlType(
SqlTypeName.DECIMAL,
scale + intervalType.getPrecision(),
scale);
value = encodeIntervalOrDecimal(value, decimalType, false);
}
return ensureType(toType, value, false);
}
private RexNode makeCastExactToInterval(RelDataType toType, RexNode exp) {
IntervalSqlType intervalType = (IntervalSqlType) toType;
TimeUnit endUnit = intervalType.getIntervalQualifier().getEndUnit();
if (endUnit == null) {
endUnit = intervalType.getIntervalQualifier().getStartUnit();
}
int scale = 0;
if (endUnit == TimeUnit.SECOND) {
scale = Math.min(
intervalType.getIntervalQualifier()
.getFractionalSecondPrecision(typeFactory.getTypeSystem()),
3);
}
BigDecimal multiplier = BigDecimal.valueOf(endUnit.multiplier)
.divide(BigDecimal.TEN.pow(scale));
RelDataType decimalType =
getTypeFactory().createSqlType(
SqlTypeName.DECIMAL,
scale + intervalType.getPrecision(),
scale);
RexNode value = decodeIntervalOrDecimal(ensureType(decimalType, exp, true));
if (multiplier.longValue() != 1) {
value = makeCall(
SqlStdOperatorTable.MULTIPLY,
value, makeExactLiteral(multiplier));
}
return encodeIntervalOrDecimal(value, toType, false);
}
/**
* Casts a decimal's integer representation to a decimal node. If the
* expression is not the expected integer type, then it is casted first.
*
* <p>An overflow check may be requested to ensure the internal value
* does not exceed the maximum value of the decimal type.
*
* @param value integer representation of decimal
* @param type type integer will be reinterpreted as
* @param checkOverflow indicates whether an overflow check is required
* when reinterpreting this particular value as the
* decimal type. A check usually not required for
* arithmetic, but is often required for rounding and
* explicit casts.
* @return the integer reinterpreted as an opaque decimal type
*/
public RexNode encodeIntervalOrDecimal(
RexNode value,
RelDataType type,
boolean checkOverflow) {
RelDataType bigintType =
typeFactory.createSqlType(
SqlTypeName.BIGINT);
RexNode cast = ensureType(bigintType, value, true);
return makeReinterpretCast(type, cast, makeLiteral(checkOverflow));
}
/**
* Retrieves an interval or decimal node's integer representation
*
* @param node the interval or decimal value as an opaque type
* @return an integer representation of the decimal value
*/
public RexNode decodeIntervalOrDecimal(RexNode node) {
assert SqlTypeUtil.isDecimal(node.getType())
|| SqlTypeUtil.isInterval(node.getType());
RelDataType bigintType = typeFactory.createSqlType(SqlTypeName.BIGINT);
return makeReinterpretCast(
matchNullability(bigintType, node), node, makeLiteral(false));
}
/**
* Creates a call to the CAST operator.
*
* @param type Type to cast to
* @param exp Expression being cast
* @return Call to CAST operator
*/
public RexNode makeAbstractCast(
RelDataType type,
RexNode exp) {
return new RexCall(
type,
SqlStdOperatorTable.CAST,
ImmutableList.of(exp));
}
/**
* Makes a reinterpret cast.
*
* @param type type returned by the cast
* @param exp expression to be casted
* @param checkOverflow whether an overflow check is required
* @return a RexCall with two operands and a special return type
*/
public RexNode makeReinterpretCast(
RelDataType type,
RexNode exp,
RexNode checkOverflow) {
List<RexNode> args;
if ((checkOverflow != null) && checkOverflow.isAlwaysTrue()) {
args = ImmutableList.of(exp, checkOverflow);
} else {
args = ImmutableList.of(exp);
}
return new RexCall(
type,
SqlStdOperatorTable.REINTERPRET,
args);
}
/**
* Makes an expression which converts a value of type T to a value of type T
* NOT NULL, or throws if the value is NULL. If the expression is already
* NOT NULL, does nothing.
*/
public RexNode makeNotNullCast(RexNode expr) {
RelDataType type = expr.getType();
if (!type.isNullable()) {
return expr;
}
RelDataType typeNotNull =
getTypeFactory().createTypeWithNullability(type, false);
return new RexCall(
typeNotNull,
SqlStdOperatorTable.CAST,
ImmutableList.of(expr));
}
/**
* Creates a reference to all the fields in the row. That is, the whole row
* as a single record object.
*
* @param input Input relational expression
*/
public RexNode makeRangeReference(RelNode input) {
return new RexRangeRef(input.getRowType(), 0);
}
/**
* Creates a reference to all the fields in the row.
*
* <p>For example, if the input row has type <code>T{f0,f1,f2,f3,f4}</code>
* then <code>makeRangeReference(T{f0,f1,f2,f3,f4}, S{f3,f4}, 3)</code> is
* an expression which yields the last 2 fields.
*
* @param type Type of the resulting range record.
* @param offset Index of first field.
* @param nullable Whether the record is nullable.
*/
public RexRangeRef makeRangeReference(
RelDataType type,
int offset,
boolean nullable) {
if (nullable && !type.isNullable()) {
type =
typeFactory.createTypeWithNullability(
type,
nullable);
}
return new RexRangeRef(type, offset);
}
/**
* Creates a reference to a given field of the input record.
*
* @param type Type of field
* @param i Ordinal of field
* @return Reference to field
*/
public RexInputRef makeInputRef(
RelDataType type,
int i) {
type = SqlTypeUtil.addCharsetAndCollation(type, typeFactory);
return new RexInputRef(i, type);
}
/**
* Creates a reference to a given field of the input relational expression.
*
* @param input Input relational expression
* @param i Ordinal of field
* @return Reference to field
*/
public RexInputRef makeInputRef(RelNode input, int i) {
return makeInputRef(input.getRowType().getFieldList().get(i).getType(), i);
}
/**
* Creates a literal representing a flag.
*
* @param flag Flag value
*/
public RexLiteral makeFlag(Enum flag) {
assert flag != null;
return makeLiteral(flag,
typeFactory.createSqlType(SqlTypeName.SYMBOL),
SqlTypeName.SYMBOL);
}
/**
* Internal method to create a call to a literal. Code outside this package
* should call one of the type-specific methods such as {@link
* #makeDateLiteral(Calendar)}, {@link #makeLiteral(boolean)}, {@link
* #makeLiteral(String)}.
*
* @param o Value of literal, must be appropriate for the type
* @param type Type of literal
* @param typeName SQL type of literal
* @return Literal
*/
protected RexLiteral makeLiteral(
Comparable o,
RelDataType type,
SqlTypeName typeName) {
// All literals except NULL have NOT NULL types.
type = typeFactory.createTypeWithNullability(type, o == null);
if (typeName == SqlTypeName.CHAR) {
// Character literals must have a charset and collation. Populate
// from the type if necessary.
assert o instanceof NlsString;
NlsString nlsString = (NlsString) o;
if ((nlsString.getCollation() == null)
|| (nlsString.getCharset() == null)) {
assert type.getSqlTypeName() == SqlTypeName.CHAR;
assert type.getCharset().name() != null;
assert type.getCollation() != null;
o = new NlsString(
nlsString.getValue(),
type.getCharset().name(),
type.getCollation());
}
}
return new RexLiteral(o, type, typeName);
}
/**
* Creates a boolean literal.
*/
public RexLiteral makeLiteral(boolean b) {
return b ? booleanTrue : booleanFalse;
}
/**
* Creates a numeric literal.
*/
public RexLiteral makeExactLiteral(BigDecimal bd) {
RelDataType relType;
int scale = bd.scale();
long l = bd.unscaledValue().longValue();
assert scale >= 0;
assert scale <= typeFactory.getTypeSystem().getMaxNumericScale() : scale;
assert BigDecimal.valueOf(l, scale).equals(bd);
if (scale == 0) {
if ((l >= Integer.MIN_VALUE) && (l <= Integer.MAX_VALUE)) {
relType = typeFactory.createSqlType(SqlTypeName.INTEGER);
} else {
relType = typeFactory.createSqlType(SqlTypeName.BIGINT);
}
} else {
int precision = bd.unscaledValue().toString().length();
relType =
typeFactory.createSqlType(
SqlTypeName.DECIMAL, scale, precision);
}
return makeExactLiteral(bd, relType);
}
/**
* Creates a BIGINT literal.
*/
public RexLiteral makeBigintLiteral(BigDecimal bd) {
RelDataType bigintType =
typeFactory.createSqlType(
SqlTypeName.BIGINT);
return makeLiteral(bd, bigintType, SqlTypeName.DECIMAL);
}
/**
* Creates a numeric literal.
*/
public RexLiteral makeExactLiteral(BigDecimal bd, RelDataType type) {
return makeLiteral(bd, type, SqlTypeName.DECIMAL);
}
/**
* Creates a byte array literal.
*/
public RexLiteral makeBinaryLiteral(ByteString byteString) {
return makeLiteral(
byteString,
typeFactory.createSqlType(SqlTypeName.BINARY, byteString.length()),
SqlTypeName.BINARY);
}
/**
* Creates a double-precision literal.
*/
public RexLiteral makeApproxLiteral(BigDecimal bd) {
// Validator should catch if underflow is allowed
// If underflow is allowed, let underflow become zero
if (bd.doubleValue() == 0) {
bd = BigDecimal.ZERO;
}
return makeApproxLiteral(bd, typeFactory.createSqlType(SqlTypeName.DOUBLE));
}
/**
* Creates an approximate numeric literal (double or float).
*
* @param bd literal value
* @param type approximate numeric type
* @return new literal
*/
public RexLiteral makeApproxLiteral(BigDecimal bd, RelDataType type) {
assert SqlTypeFamily.APPROXIMATE_NUMERIC.getTypeNames().contains(
type.getSqlTypeName());
return makeLiteral(bd, type, SqlTypeName.DOUBLE);
}
/**
* Creates a character string literal.
*/
public RexLiteral makeLiteral(String s) {
assert s != null;
return makePreciseStringLiteral(s);
}
/**
* Creates a character string literal with type CHAR and default charset and
* collation.
*
* @param s String value
* @return Character string literal
*/
protected RexLiteral makePreciseStringLiteral(String s) {
assert s != null;
if (s.equals("")) {
return charEmpty;
} else {
return makeLiteral(
new NlsString(s, null, null),
typeFactory.createSqlType(
SqlTypeName.CHAR,
s.length()),
SqlTypeName.CHAR);
}
}
/**
* Ensures expression is interpreted as a specified type. The returned
* expression may be wrapped with a cast.
*
* @param type desired type
* @param node expression
* @param matchNullability whether to correct nullability of specified
* type to match the expression; this usually should
* be true, except for explicit casts which can
* override default nullability
* @return a casted expression or the original expression
*/
public RexNode ensureType(
RelDataType type,
RexNode node,
boolean matchNullability) {
RelDataType targetType = type;
if (matchNullability) {
targetType = matchNullability(type, node);
}
if (!node.getType().equals(targetType)) {
return makeCast(targetType, node);
}
return node;
}
/**
* Ensures that a type's nullability matches a value's nullability.
*/
public RelDataType matchNullability(
RelDataType type,
RexNode value) {
boolean typeNullability = type.isNullable();
boolean valueNullability = value.getType().isNullable();
if (typeNullability != valueNullability) {
return getTypeFactory().createTypeWithNullability(
type,
valueNullability);
}
return type;
}
/**
* Creates a character string literal from an {@link NlsString}.
*
* <p>If the string's charset and collation are not set, uses the system
* defaults.
*/
public RexLiteral makeCharLiteral(NlsString str) {
assert str != null;
RelDataType type = SqlUtil.createNlsStringType(typeFactory, str);
return makeLiteral(str, type, SqlTypeName.CHAR);
}
/**
* Creates a Date literal.
*/
public RexLiteral makeDateLiteral(Calendar date) {
assert date != null;
return makeLiteral(
date, typeFactory.createSqlType(SqlTypeName.DATE), SqlTypeName.DATE);
}
/**
* Creates a Time literal.
*/
public RexLiteral makeTimeLiteral(
Calendar time,
int precision) {
assert time != null;
return makeLiteral(
time,
typeFactory.createSqlType(SqlTypeName.TIME, precision),
SqlTypeName.TIME);
}
/**
* Creates a Timestamp literal.
*/
public RexLiteral makeTimestampLiteral(
Calendar timestamp,
int precision) {
assert timestamp != null;
return makeLiteral(
timestamp,
typeFactory.createSqlType(SqlTypeName.TIMESTAMP, precision),
SqlTypeName.TIMESTAMP);
}
/**
* Creates an interval literal.
*/
public RexLiteral makeIntervalLiteral(
SqlIntervalQualifier intervalQualifier) {
assert intervalQualifier != null;
return makeFlag(intervalQualifier.foo());
}
/**
* Creates an interval literal.
*/
public RexLiteral makeIntervalLiteral(
BigDecimal v,
SqlIntervalQualifier intervalQualifier) {
return makeLiteral(
v,
typeFactory.createSqlIntervalType(intervalQualifier),
intervalQualifier.isYearMonth() ? SqlTypeName.INTERVAL_YEAR_MONTH
: SqlTypeName.INTERVAL_DAY_TIME);
}
/**
* Creates a reference to a dynamic parameter
*
* @param type Type of dynamic parameter
* @param index Index of dynamic parameter
* @return Expression referencing dynamic parameter
*/
public RexDynamicParam makeDynamicParam(
RelDataType type,
int index) {
return new RexDynamicParam(type, index);
}
/**
* Creates an expression corresponding to a null literal, cast to a specific
* type and precision
*
* @param typeName name of the type that the null will be cast to
* @param precision precision of the type
* @return created expression
*/
public RexNode makeNullLiteral(SqlTypeName typeName, int precision) {
RelDataType type =
typeFactory.createTypeWithNullability(
typeFactory.createSqlType(typeName, precision),
true);
return makeCast(type, constantNull());
}
/**
* Creates a literal whose value is NULL, with a particular type.
*
* <p>The typing is necessary because RexNodes are strictly typed. For
* example, in the Rex world the <code>NULL</code> parameter to <code>
* SUBSTRING(NULL FROM 2 FOR 4)</code> must have a valid VARCHAR type so
* that the result type can be determined.
*
* @param typeName Type to cast NULL to
* @return NULL literal of given type
*/
public RexNode makeNullLiteral(SqlTypeName typeName) {
RelDataType type =
typeFactory.createTypeWithNullability(
typeFactory.createSqlType(typeName),
true);
return makeCast(type, constantNull());
}
/**
* Creates a copy of an expression, which may have been created using a
* different RexBuilder and/or {@link RelDataTypeFactory}, using this
* RexBuilder.
*
* @param expr Expression
* @return Copy of expression
* @see RelDataTypeFactory#copyType(RelDataType)
*/
public RexNode copy(RexNode expr) {
return expr.accept(new RexCopier(this));
}
/**
* Creates a literal of the default value for the given type.
*
* <p>This value is:</p>
*
* <ul>
* <li>0 for numeric types;
* <li>FALSE for BOOLEAN;
* <li>The epoch for TIMESTAMP and DATE;
* <li>Midnight for TIME;
* <li>The empty string for string types (CHAR, BINARY, VARCHAR, VARBINARY).
* </ul>
*
* @param type Type
* @return Simple literal, or cast simple literal
*/
public RexNode makeZeroLiteral(RelDataType type) {
return makeLiteral(zeroValue(type), type, false);
}
private static Comparable zeroValue(RelDataType type) {
switch (type.getSqlTypeName()) {
case CHAR:
return new NlsString(Spaces.of(type.getPrecision()), null, null);
case VARCHAR:
return new NlsString("", null, null);
case BINARY:
return new ByteString(new byte[type.getPrecision()]);
case VARBINARY:
return ByteString.EMPTY;
case TINYINT:
case SMALLINT:
case INTEGER:
case BIGINT:
case DECIMAL:
case FLOAT:
case REAL:
case DOUBLE:
return BigDecimal.ZERO;
case BOOLEAN:
return false;
case TIME:
case DATE:
case TIMESTAMP:
return DateTimeUtil.ZERO_CALENDAR;
default:
throw Util.unexpected(type.getSqlTypeName());
}
}
/**
* Creates a literal of a given type. The value is assumed to be
* compatible with the type.
*
* @param value Value
* @param type Type
* @param allowCast Whether to allow a cast. If false, value is always a
* {@link RexLiteral} but may not be the exact type
* @return Simple literal, or cast simple literal
*/
public RexNode makeLiteral(Object value, RelDataType type,
boolean allowCast) {
if (value == null) {
return makeCast(type, constantNull);
}
if (type.isNullable()) {
final RelDataType typeNotNull =
typeFactory.createTypeWithNullability(type, false);
RexNode literalNotNull = makeLiteral(value, typeNotNull, allowCast);
return makeAbstractCast(type, literalNotNull);
}
value = clean(value, type);
RexLiteral literal;
final List<RexNode> operands;
switch (type.getSqlTypeName()) {
case CHAR:
return makeCharLiteral(padRight((NlsString) value, type.getPrecision()));
case VARCHAR:
literal = makeCharLiteral((NlsString) value);
if (allowCast) {
return makeCast(type, literal);
} else {
return literal;
}
case BINARY:
return makeBinaryLiteral(
padRight((ByteString) value, type.getPrecision()));
case VARBINARY:
literal = makeBinaryLiteral((ByteString) value);
if (allowCast) {
return makeCast(type, literal);
} else {
return literal;
}
case TINYINT:
case SMALLINT:
case INTEGER:
case BIGINT:
case DECIMAL:
return makeExactLiteral((BigDecimal) value, type);
case FLOAT:
case REAL:
case DOUBLE:
return makeApproxLiteral((BigDecimal) value, type);
case BOOLEAN:
return (Boolean) value ? booleanTrue : booleanFalse;
case TIME:
return makeTimeLiteral((Calendar) value, type.getPrecision());
case DATE:
return makeDateLiteral((Calendar) value);
case TIMESTAMP:
return makeTimestampLiteral((Calendar) value, type.getPrecision());
case INTERVAL_YEAR_MONTH:
case INTERVAL_DAY_TIME:
return makeIntervalLiteral((BigDecimal) value,
type.getIntervalQualifier());
case MAP:
final MapSqlType mapType = (MapSqlType) type;
@SuppressWarnings("unchecked")
final Map<Object, Object> map = (Map) value;
operands = new ArrayList<RexNode>();
for (Map.Entry<Object, Object> entry : map.entrySet()) {
operands.add(
makeLiteral(entry.getKey(), mapType.getKeyType(), allowCast));
operands.add(
makeLiteral(entry.getValue(), mapType.getValueType(), allowCast));
}
return makeCall(SqlStdOperatorTable.MAP_VALUE_CONSTRUCTOR, operands);
case ARRAY:
final ArraySqlType arrayType = (ArraySqlType) type;
@SuppressWarnings("unchecked")
final List<Object> listValue = (List) value;
operands = new ArrayList<RexNode>();
for (Object entry : listValue) {
operands.add(
makeLiteral(entry, arrayType.getComponentType(), allowCast));
}
return makeCall(SqlStdOperatorTable.ARRAY_VALUE_CONSTRUCTOR, operands);
case ANY:
return makeLiteral(value, guessType(value), allowCast);
default:
throw Util.unexpected(type.getSqlTypeName());
}
}
/** Converts the type of a value to comply with
* {@link org.eigenbase.rex.RexLiteral#valueMatchesType}. */
private static Object clean(Object o, RelDataType type) {
if (o == null) {
return null;
}
final Calendar calendar;
switch (type.getSqlTypeName()) {
case TINYINT:
case SMALLINT:
case INTEGER:
case BIGINT:
case DECIMAL:
case INTERVAL_YEAR_MONTH:
case INTERVAL_DAY_TIME:
if (o instanceof BigDecimal) {
return o;
}
return new BigDecimal(((Number) o).longValue());
case FLOAT:
case REAL:
case DOUBLE:
if (o instanceof BigDecimal) {
return o;
}
return new BigDecimal(((Number) o).doubleValue());
case CHAR:
case VARCHAR:
if (o instanceof NlsString) {
return o;
}
return new NlsString((String) o, type.getCharset().name(),
type.getCollation());
case TIME:
if (o instanceof Calendar) {
return o;
}
calendar = Calendar.getInstance(DateTimeUtil.GMT_ZONE);
calendar.setTimeInMillis((Integer) o);
return calendar;
case DATE:
if (o instanceof Calendar) {
return o;
}
calendar = Calendar.getInstance(DateTimeUtil.GMT_ZONE);
calendar.setTimeInMillis(0);
calendar.add(Calendar.DAY_OF_YEAR, (Integer) o);
return calendar;
case TIMESTAMP:
if (o instanceof Calendar) {
return o;
}
calendar = Calendar.getInstance(DateTimeUtil.GMT_ZONE);
calendar.setTimeInMillis((Long) o);
return calendar;
default:
return o;
}
}
private RelDataType guessType(Object value) {
if (value == null) {
return typeFactory.createSqlType(SqlTypeName.NULL);
}
if (value instanceof Float || value instanceof Double) {
return typeFactory.createSqlType(SqlTypeName.DOUBLE);
}
if (value instanceof Number) {
return typeFactory.createSqlType(SqlTypeName.BIGINT);
}
if (value instanceof Boolean) {
return typeFactory.createSqlType(SqlTypeName.BOOLEAN);
}
if (value instanceof String) {
return typeFactory.createSqlType(SqlTypeName.CHAR,
((String) value).length());
}
if (value instanceof ByteString) {
return typeFactory.createSqlType(SqlTypeName.BINARY,
((ByteString) value).length());
}
throw new AssertionError("unknown type " + value.getClass());
}
/** Returns an {@link NlsString} with spaces to make it at least a given
* length. */
private static NlsString padRight(NlsString s, int length) {
if (s.getValue().length() >= length) {
return s;
}
return s.copy(padRight(s.getValue(), length));
}
/** Returns a string padded with spaces to make it at least a given length. */
private static String padRight(String s, int length) {
if (s.length() >= length) {
return s;
}
return new StringBuilder()
.append(s)
.append(Spaces.MAX, s.length(), length)
.toString();
}
/** Returns a byte-string padded with zero bytes to make it at least a given
* length, */
private static ByteString padRight(ByteString s, int length) {
if (s.length() >= length) {
return s;
}
return new ByteString(Arrays.copyOf(s.getBytes(), length));
}
}
// End RexBuilder.java