/* Copyright (c) 2001-2009, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb;
import org.hsqldb.HSQLInterface.HSQLParseException;
import org.hsqldb.lib.HsqlList;
import org.hsqldb.types.DateTimeType;
import org.hsqldb.types.IntervalType;
import org.hsqldb.types.Type;
/**
* Implementation of CASE, LIMIT and ZONE operations.
*
* @author Campbell Boucher-Burnett (boucherb@users dot sourceforge.net)
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 1.9.0
* @since 1.9.0
*/
public class ExpressionOp extends Expression {
/**
* Creates a binary operation expression
*/
ExpressionOp(int type, Expression left, Expression right) {
super(type);
nodes = new Expression[BINARY];
nodes[LEFT] = left;
nodes[RIGHT] = right;
switch (opType) {
case OpTypes.ALTERNATIVE :
case OpTypes.CASEWHEN :
case OpTypes.LIMIT :
case OpTypes.ZONE_MODIFIER :
return;
default :
throw Error.runtimeError(ErrorCode.U_S0500, "Expression");
}
}
/**
* creates a CAST expression
*/
ExpressionOp(Expression e, Type dataType) {
super(OpTypes.CAST);
nodes = new Expression[UNARY];
nodes[LEFT] = e;
this.dataType = dataType;
this.alias = e.alias;
}
/**
* creates a special conversion for time / timestamp comparison
*/
ExpressionOp(Expression e) {
super(e.dataType.isDateTimeTypeWithZone() ? OpTypes.CAST
: OpTypes.ZONE_MODIFIER);
switch (e.dataType.typeCode) {
case Types.SQL_TIME_WITH_TIME_ZONE :
nodes = new Expression[UNARY];
nodes[LEFT] = new ExpressionOp(OpTypes.ZONE_MODIFIER, e, null);
dataType = DateTimeType.getDateTimeType(Types.SQL_TIME,
e.dataType.scale);
break;
case Types.SQL_TIMESTAMP_WITH_TIME_ZONE :
nodes = new Expression[UNARY];
nodes[LEFT] = new ExpressionOp(OpTypes.ZONE_MODIFIER, e, null);
dataType = DateTimeType.getDateTimeType(Types.SQL_TIMESTAMP,
e.dataType.scale);
break;
case Types.SQL_TIME :
nodes = new Expression[BINARY];
nodes[LEFT] = e;
dataType =
DateTimeType.getDateTimeType(Types.SQL_TIME_WITH_TIME_ZONE,
e.dataType.scale);
break;
case Types.SQL_TIMESTAMP :
nodes = new Expression[BINARY];
nodes[LEFT] = e;
dataType = DateTimeType.getDateTimeType(
Types.SQL_TIMESTAMP_WITH_TIME_ZONE, e.dataType.scale);
break;
default :
throw Error.runtimeError(ErrorCode.U_S0500, "Expression");
}
this.alias = e.alias;
}
public String getSQL() {
StringBuffer sb = new StringBuffer(64);
String left = getContextSQL(nodes.length > 0 ? nodes[LEFT]
: null);
String right = getContextSQL(nodes.length > 1 ? nodes[RIGHT]
: null);
switch (opType) {
case OpTypes.VALUE :
if (valueData == null) {
return Tokens.T_NULL;
}
if (dataType == null) {
throw Error.runtimeError(ErrorCode.U_S0500,
"Expression.getSQL()");
}
return dataType.convertToSQLString(valueData);
case OpTypes.CAST :
sb.append(' ').append(Tokens.T_CAST).append('(');
sb.append(left).append(' ').append(Tokens.T_AS).append(' ');
sb.append(dataType.getTypeDefinition());
sb.append(')');
return sb.toString();
case OpTypes.CASEWHEN :
sb.append(' ').append(Tokens.T_CASEWHEN).append('(');
sb.append(left).append(',').append(right).append(')');
return sb.toString();
case OpTypes.ALTERNATIVE :
sb.append(left).append(',').append(right);
return sb.toString();
case OpTypes.LIMIT :
sb.append(' ').append(Tokens.T_OFFSET).append(' ');
sb.append(left).append(' ');
sb.append(Tokens.T_FETCH).append(' ').append(Tokens.T_FIRST);
sb.append(right).append(' ').append(right).append(' ');
sb.append(Tokens.T_ROWS).append(' ').append(Tokens.T_ONLY);
sb.append(' ');
break;
case OpTypes.ZONE_MODIFIER :
sb.append(left).append(' ').append(Tokens.T_AT).append(' ');
if (nodes[RIGHT] == null) {
sb.append(Tokens.T_LOCAL).append(' ');
break;
}
sb.append(right);
break;
default :
throw Error.runtimeError(ErrorCode.U_S0500, "Expression");
}
return sb.toString();
}
protected String describe(Session session, int blanks) {
StringBuffer sb = new StringBuffer(64);
sb.append('\n');
for (int i = 0; i < blanks; i++) {
sb.append(' ');
}
switch (opType) {
case OpTypes.VALUE :
sb.append("VALUE = ").append(valueData);
sb.append(", TYPE = ").append(dataType.getNameString());
return sb.toString();
case OpTypes.TABLE :
sb.append("VALUELIST ");
for (int i = 0; i < nodes.length; i++) {
sb.append(nodes[i].describe(session, blanks + 1));
sb.append(' ');
}
break;
case OpTypes.CAST :
sb.append("CAST ");
sb.append(dataType.getTypeDefinition());
sb.append(' ');
break;
case OpTypes.CASEWHEN :
sb.append("CASEWHEN ");
break;
}
if (nodes[LEFT] != null) {
sb.append(" arg1=[");
sb.append(nodes[LEFT].describe(session, blanks + 1));
sb.append(']');
}
if (nodes[RIGHT] != null) {
sb.append(" arg2=[");
sb.append(nodes[RIGHT].describe(session, blanks + 1));
sb.append(']');
}
return sb.toString();
}
public HsqlList resolveColumnReferences(RangeVariable[] rangeVarArray,
int rangeCount, HsqlList unresolvedSet, boolean acceptsSequences) {
if (opType == OpTypes.VALUE) {
return unresolvedSet;
}
switch (opType) {
case OpTypes.CASEWHEN :
acceptsSequences = false;
break;
}
for (int i = 0; i < nodes.length; i++) {
if (nodes[i] == null) {
continue;
}
unresolvedSet = nodes[i].resolveColumnReferences(rangeVarArray,
rangeCount, unresolvedSet, acceptsSequences);
}
return unresolvedSet;
}
public void resolveTypes(Session session, Expression parent) {
for (int i = 0; i < nodes.length; i++) {
if (nodes[i] != null) {
nodes[i].resolveTypes(session, this);
}
}
switch (opType) {
case OpTypes.VALUE :
break;
case OpTypes.CAST : {
Type type = nodes[LEFT].dataType;
if (type != null && !dataType.canConvertFrom(type)) {
throw Error.error(ErrorCode.X_42561);
}
if (nodes[LEFT].opType == OpTypes.VALUE) {
setAsConstantValue(session);
break;
}
break;
}
case OpTypes.ZONE_MODIFIER :
if (nodes[LEFT].dataType == null) {
throw Error.error(ErrorCode.X_42567);
}
if (nodes[RIGHT] != null) {
if (nodes[RIGHT].dataType == null) {
nodes[RIGHT].dataType =
Type.SQL_INTERVAL_HOUR_TO_MINUTE;
}
if (nodes[RIGHT].dataType.typeCode
!= Types.SQL_INTERVAL_HOUR_TO_MINUTE) {
throw Error.error(ErrorCode.X_42565);
}
}
switch (nodes[LEFT].dataType.typeCode) {
case Types.SQL_TIME :
dataType = DateTimeType.getDateTimeType(
Types.SQL_TIME_WITH_TIME_ZONE,
nodes[LEFT].dataType.scale);
break;
case Types.SQL_TIMESTAMP :
dataType = DateTimeType.getDateTimeType(
Types.SQL_TIMESTAMP_WITH_TIME_ZONE,
nodes[LEFT].dataType.scale);
break;
case Types.SQL_TIMESTAMP_WITH_TIME_ZONE :
case Types.SQL_TIME_WITH_TIME_ZONE :
dataType = nodes[LEFT].dataType;
break;
default :
throw Error.error(ErrorCode.X_42565);
}
// no constant optimisation as value dependent on session zone
break;
case OpTypes.CASEWHEN :
// We use CASEWHEN as parent type.
// In the parent, left node is the condition, and right node is
// the leaf, tagged as type ALTERNATIVE; its left node is
// case 1 (how to get the value when the condition in
// the parent evaluates to true), while its right node is case 2
// (how to get the value when the condition in
// the parent evaluates to false).
resolveTypesForCaseWhen(session);
break;
case OpTypes.ALTERNATIVE :
break;
default :
throw Error.runtimeError(ErrorCode.U_S0500,
"Expression.resolveTypes()");
}
}
/**
* For CASE WHEN and its special cases section 9.3 of the SQL standard
* on type aggregation is implemented.
*/
void resolveTypesForCaseWhen(Session session) {
if (dataType != null) {
return;
}
Expression expr = this;
while (expr.opType == OpTypes.CASEWHEN) {
expr.nodes[LEFT].resolveTypes(session, expr);
if (expr.nodes[LEFT].isParam) {
expr.nodes[LEFT].dataType = Type.SQL_BOOLEAN;
}
expr.nodes[RIGHT].nodes[LEFT].resolveTypes(session, nodes[RIGHT]);
expr.nodes[RIGHT].nodes[RIGHT].resolveTypes(session, nodes[RIGHT]);
expr = expr.nodes[RIGHT].nodes[RIGHT];
}
expr = this;
while (expr.opType == OpTypes.CASEWHEN) {
dataType =
Type.getAggregateType(expr.nodes[RIGHT].nodes[LEFT].dataType,
dataType);
dataType =
Type.getAggregateType(expr.nodes[RIGHT].nodes[RIGHT].dataType,
dataType);
expr = expr.nodes[RIGHT].nodes[RIGHT];
}
expr = this;
while (expr.opType == OpTypes.CASEWHEN) {
if (expr.nodes[RIGHT].nodes[LEFT].dataType == null) {
expr.nodes[RIGHT].nodes[LEFT].dataType = dataType;
}
if (expr.nodes[RIGHT].nodes[RIGHT].dataType == null) {
expr.nodes[RIGHT].nodes[RIGHT].dataType = dataType;
}
if (expr.nodes[RIGHT].dataType == null) {
expr.nodes[RIGHT].dataType = dataType;
}
expr = expr.nodes[RIGHT].nodes[RIGHT];
}
if (dataType == null) {
throw Error.error(ErrorCode.X_42567);
}
}
public Object getValue(Session session) {
switch (opType) {
case OpTypes.VALUE :
return valueData;
case OpTypes.SIMPLE_COLUMN : {
Object[] data =
(Object[]) session.sessionContext
.rangeIterators[rangePosition].getCurrent();
return data[columnIndex];
}
case OpTypes.ORDER_BY :
return nodes[LEFT].getValue(session);
case OpTypes.CAST : {
Object value =
dataType.castToType(session,
nodes[LEFT].getValue(session),
nodes[LEFT].dataType);
if (dataType.userTypeModifier != null) {
Constraint[] constraints =
dataType.userTypeModifier.getConstraints();
for (int i = 0; i < constraints.length; i++) {
constraints[i].checkCheckConstraint(session, null,
value);
}
}
return value;
}
case OpTypes.CASEWHEN : {
Boolean result = (Boolean) nodes[LEFT].getValue(session);
if (Boolean.TRUE.equals(result)) {
return nodes[RIGHT].nodes[LEFT].getValue(session,
dataType);
} else {
return nodes[RIGHT].nodes[RIGHT].getValue(session,
dataType);
}
}
case OpTypes.ZONE_MODIFIER : {
Object leftValue = nodes[LEFT].getValue(session);
Object rightValue = nodes[RIGHT] == null ? null
: nodes[RIGHT]
.getValue(
session);
if (leftValue == null) {
return null;
}
if (nodes[RIGHT] != null && rightValue == null) {
return null;
}
long zoneSeconds = nodes[RIGHT] == null
? session.timeZoneSeconds
: ((IntervalType) nodes[RIGHT].dataType)
.getSeconds(rightValue);
return ((DateTimeType) dataType).changeZone(leftValue,
nodes[LEFT].dataType, (int) zoneSeconds,
session.timeZoneSeconds);
}
default :
throw Error.runtimeError(ErrorCode.U_S0500, "Expression");
}
}
/*************** VOLTDB *********************/
/**
* VoltDB added method to get a non-catalog-dependent
* representation of this HSQLDB object.
* @param session The current Session object may be needed to resolve
* some names.
* @param indent A string of whitespace to be prepended to every line
* in the resulting XML.
* @return XML, correctly indented, representing this object.
* @throws HSQLParseException
*/
String voltGetXML(Session session, String indent) throws HSQLParseException
{
String element = null;
switch (opType) {
case OpTypes.LIMIT: element = "limit"; break;
case OpTypes.ADD: element = "add"; break;
case OpTypes.SUBTRACT: element = "subtract"; break;
case OpTypes.MULTIPLY: element = "multiply"; break;
case OpTypes.DIVIDE: element = "divide"; break;
case OpTypes.EQUAL: element = "equal"; break;
case OpTypes.NOT_EQUAL: element = "notequal"; break;
case OpTypes.GREATER: element = "greaterthan"; break;
case OpTypes.GREATER_EQUAL: element = "greaterthanorequalto"; break;
case OpTypes.SMALLER: element = "lessthan"; break;
case OpTypes.SMALLER_EQUAL: element = "lessthanorequalto"; break;
case OpTypes.AND: element = "and"; break;
case OpTypes.OR: element = "or"; break;
case OpTypes.IN: element = "in"; break;
case OpTypes.COUNT: element = "count"; break;
case OpTypes.SUM: element = "sum"; break;
case OpTypes.MIN: element = "min"; break;
case OpTypes.MAX: element = "max"; break;
case OpTypes.AVG: element = "avg"; break;
case OpTypes.SQL_FUNCTION: element = "function"; break;
default:
throw new HSQLParseException("Unsupported Operation: " +
String.valueOf(opType));
}
StringBuffer sb = new StringBuffer();
sb.append(indent).append("<operation id=\"").append(this.getUniqueId()).append("\"");
sb.append(" type=\"").append(element).append("\"");
if ((this.alias != null) && (getAlias().length() > 0)) {
sb.append(" alias='" + getAlias() + "'");
}
sb.append(">\n");
for (Expression expr : nodes) {
sb.append(expr.voltGetXML(session, indent + HSQLInterface.XML_INDENT)).append('\n');
}
sb.append(indent).append("</operation>");
return sb.toString();
}
}