/*
Derby - Class org.apache.derby.impl.sql.compile.ConcatenationOperatorNode
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.derby.impl.sql.compile;
import org.apache.derby.iapi.sql.compile.C_NodeTypes;
import org.apache.derby.iapi.services.sanity.SanityManager;
import org.apache.derby.iapi.error.StandardException;
import org.apache.derby.iapi.types.TypeId;
import org.apache.derby.iapi.sql.compile.TypeCompiler;
import org.apache.derby.iapi.types.StringDataValue;
import org.apache.derby.iapi.types.DataTypeDescriptor;
import org.apache.derby.iapi.services.compiler.MethodBuilder;
import org.apache.derby.iapi.services.compiler.LocalField;
import org.apache.derby.impl.sql.compile.ExpressionClassBuilder;
import org.apache.derby.iapi.reference.Limits;
import org.apache.derby.iapi.reference.SQLState;
import org.apache.derby.iapi.reference.ClassName;
import java.sql.Types;
import java.util.Vector;
/**
* This node represents a concatenation comparison operator
*
* varying.
*/
public class ConcatenationOperatorNode extends BinaryOperatorNode {
/**
* Initializer for a ConcatenationOperatorNode
*
* @param leftOperand
* The left operand of the concatenation
* @param rightOperand
* The right operand of the concatenation
*/
public void init(Object leftOperand, Object rightOperand) {
super.init(leftOperand, rightOperand, "||", "concatenate",
ClassName.ConcatableDataValue, ClassName.ConcatableDataValue);
}
/**
* Check if this node always evaluates to the same value. If so, return
* a constant node representing the known result.
*
* @return a constant node representing the result of this concatenation
* operation, or {@code this} if the result is not known up front
*/
ValueNode evaluateConstantExpressions() throws StandardException {
if (leftOperand instanceof CharConstantNode &&
rightOperand instanceof CharConstantNode) {
CharConstantNode leftOp = (CharConstantNode) leftOperand;
CharConstantNode rightOp = (CharConstantNode) rightOperand;
StringDataValue leftValue = (StringDataValue) leftOp.getValue();
StringDataValue rightValue = (StringDataValue) rightOp.getValue();
StringDataValue resultValue =
(StringDataValue) getTypeServices().getNull();
resultValue.concatenate(leftValue, rightValue, resultValue);
return (ValueNode) getNodeFactory().getNode(
C_NodeTypes.CHAR_CONSTANT_NODE,
resultValue.getString(),
getContextManager());
}
return this;
}
/**
* overrides BindOperatorNode.bindExpression because concatenation has
* special requirements for parameter binding.
*
* @exception StandardException
* thrown on failure
*/
public ValueNode bindExpression(FromList fromList,
SubqueryList subqueryList, Vector aggregateVector)
throws StandardException {
// deal with binding operands
leftOperand = leftOperand.bindExpression(fromList, subqueryList,
aggregateVector);
rightOperand = rightOperand.bindExpression(fromList, subqueryList,
aggregateVector);
// deal with operand parameters
/*
* Is there a ? parameter on the left? If so, it's type is the type of
* the other parameter, with maximum length for that type.
*/
if (leftOperand.requiresTypeFromContext()) {
if (rightOperand.requiresTypeFromContext()) {
throw StandardException.newException(
SQLState.LANG_BINARY_OPERANDS_BOTH_PARMS, operator);
}
TypeId leftType;
/*
* * A ? on the left gets its type from the right. There are eight *
* legal types for the concatenation operator: CHAR, VARCHAR, * LONG
* VARCHAR, CLOB, BIT, BIT VARYING, LONG BIT VARYING, and BLOB. * If
* the right type is BLOB, set the parameter type to BLOB with max
* length. * If the right type is one of the other bit types, set
* the parameter type to * BIT VARYING with maximum length. * * If
* the right type is CLOB, set parameter type to CLOB with max
* length. * If the right type is anything else, set it to VARCHAR
* with * maximum length. We count on the resolveConcatOperation
* method to * catch an illegal type. * * NOTE: When I added the
* long types, I could have changed the * resulting parameter types
* to LONG VARCHAR and LONG BIT VARYING, * but they were already
* VARCHAR and BIT VARYING, and it wasn't * clear to me what effect
* it would have to change it. - Jeff
*/
if (rightOperand.getTypeId().isBitTypeId()) {
if (rightOperand.getTypeId().isBlobTypeId())
leftType = TypeId.getBuiltInTypeId(Types.BLOB);
else
leftType = TypeId.getBuiltInTypeId(Types.VARBINARY);
} else {
if (rightOperand.getTypeId().isClobTypeId())
leftType = TypeId.getBuiltInTypeId(Types.CLOB);
else
leftType = TypeId.getBuiltInTypeId(Types.VARCHAR);
}
leftOperand.setType(new DataTypeDescriptor(leftType, true));
if (rightOperand.getTypeId().isStringTypeId()) {
//collation of ? operand should be picked from the context
leftOperand.setCollationInfo(rightOperand.getTypeServices());
}
}
/*
* Is there a ? parameter on the right?
*/
if (rightOperand.requiresTypeFromContext()) {
TypeId rightType;
/*
* * A ? on the right gets its type from the left. There are eight *
* legal types for the concatenation operator: CHAR, VARCHAR, * LONG
* VARCHAR, CLOB, BIT, BIT VARYING, LONG BIT VARYING, and BLOB. * If
* the left type is BLOB, set the parameter type to BLOB with max
* length. * If the left type is one of the other bit types, set the
* parameter type to * BIT VARYING with maximum length. * * If the
* left type is CLOB, set parameter type to CLOB with max length. *
* If the left type is anything else, set it to VARCHAR with *
* maximum length. We count on the resolveConcatOperation method to *
* catch an illegal type. * * NOTE: When I added the long types, I
* could have changed the * resulting parameter types to LONG
* VARCHAR and LONG BIT VARYING, * but they were already VARCHAR and
* BIT VARYING, and it wasn't * clear to me what effect it would
* have to change it. - Jeff
*/
if (leftOperand.getTypeId().isBitTypeId()) {
if (leftOperand.getTypeId().isBlobTypeId())
rightType = TypeId.getBuiltInTypeId(Types.BLOB);
else
rightType = TypeId.getBuiltInTypeId(Types.VARBINARY);
} else {
if (leftOperand.getTypeId().isClobTypeId())
rightType = TypeId.getBuiltInTypeId(Types.CLOB);
else
rightType = TypeId.getBuiltInTypeId(Types.VARCHAR);
}
rightOperand.setType(new DataTypeDescriptor(rightType, true));
if (leftOperand.getTypeId().isStringTypeId()) {
//collation of ? operand should be picked from the context
rightOperand.setCollationInfo(leftOperand.getTypeServices());
}
}
/*
* If the left operand is not a built-in type, then generate a bound
* conversion tree to a built-in type.
*/
if (leftOperand.getTypeId().userType()) {
leftOperand = leftOperand.genSQLJavaSQLTree();
}
/*
* If the right operand is not a built-in type, then generate a bound
* conversion tree to a built-in type.
*/
if (rightOperand.getTypeId().userType()) {
rightOperand = rightOperand.genSQLJavaSQLTree();
}
/*
* If either the left or right operands are non-string, non-bit types,
* then we generate an implicit cast to VARCHAR.
*/
TypeCompiler tc = leftOperand.getTypeCompiler();
if (!(leftOperand.getTypeId().isStringTypeId() || leftOperand
.getTypeId().isBitTypeId())) {
DataTypeDescriptor dtd = DataTypeDescriptor.getBuiltInDataTypeDescriptor(
Types.VARCHAR, true, tc
.getCastToCharWidth(leftOperand .getTypeServices()));
leftOperand = (ValueNode) getNodeFactory().getNode(
C_NodeTypes.CAST_NODE,
leftOperand,
dtd,
getContextManager());
// DERBY-2910 - Match current schema collation for implicit cast as we do for
// explicit casts per SQL Spec 6.12 (10)
leftOperand.setCollationUsingCompilationSchema();
((CastNode) leftOperand).bindCastNodeOnly();
}
tc = rightOperand.getTypeCompiler();
if (!(rightOperand.getTypeId().isStringTypeId() || rightOperand
.getTypeId().isBitTypeId())) {
DataTypeDescriptor dtd = DataTypeDescriptor.getBuiltInDataTypeDescriptor(
Types.VARCHAR, true, tc
.getCastToCharWidth(rightOperand
.getTypeServices()));
rightOperand = (ValueNode) getNodeFactory().getNode(
C_NodeTypes.CAST_NODE,
rightOperand,
dtd,
getContextManager());
// DERBY-2910 - Match current schema collation for implicit cast as we do for
// explicit casts per SQL Spec 6.12 (10)
rightOperand.setCollationUsingCompilationSchema();
((CastNode) rightOperand).bindCastNodeOnly();
}
/*
* * Set the result type of this operator based on the operands. * By
* convention, the left operand gets to decide the result type * of a
* binary operator.
*/
tc = leftOperand.getTypeCompiler();
setType(resolveConcatOperation(leftOperand.getTypeServices(),
rightOperand.getTypeServices()));
/*
* * Make sure the maximum width set for the result doesn't exceed the
* result type's maximum width
*/
if (SanityManager.DEBUG) {
if (getTypeServices().getMaximumWidth() > getTypeId()
.getMaximumMaximumWidth()) {
SanityManager
.THROWASSERT("The maximum length "
+ getTypeServices().getMaximumWidth()
+ " for the result type "
+ getTypeId().getSQLTypeName()
+ " can't be greater than it's maximum width of result's typeid"
+ getTypeId().getMaximumMaximumWidth());
}
}
/*
* * Now that we know the target interface type, set it. This assumes *
* that both operands have the same interface type, which is a safe *
* assumption for the concatenation operator.
*/
this.setLeftRightInterfaceType(tc.interfaceName());
// Finally, fold constants so that for example LIKE optimization is
// able to take advantage of concatenated literals like 'ab' || '%'.
return this.evaluateConstantExpressions();
}
/**
* Resolve a concatenation operator
*
* @param leftType
* The DataTypeDescriptor of the left operand
* @param rightType
* The DataTypeDescriptor of the right operand
*
* @return A DataTypeDescriptor telling the result type of the concatenate
* operation
*
* @exception StandardException
* BinaryOperatorNotSupported Thrown when a BinaryOperator is
* not supported on the operand types.
*/
private DataTypeDescriptor resolveConcatOperation(
DataTypeDescriptor leftType, DataTypeDescriptor rightType)
throws StandardException {
TypeId leftTypeId;
TypeId rightTypeId;
String higherType;
int resultLength;
boolean nullable;
leftTypeId = leftType.getTypeId();
rightTypeId = rightType.getTypeId();
/*
* * Check the right type to be sure it's a concatable. By convention, *
* we call this method off the TypeId of the left operand, so if * we
* get here, we know the left operand is a concatable.
*/
/*
* * Make sure we haven't been given a char and a * bit to concatenate.
*/
if (!leftTypeId.isConcatableTypeId()
|| !rightTypeId.isConcatableTypeId()
|| (rightTypeId.isBitTypeId() && leftTypeId.isStringTypeId())
|| (leftTypeId.isBitTypeId() && rightTypeId.isStringTypeId()))
throw StandardException.newException(
SQLState.LANG_DB2_FUNCTION_INCOMPATIBLE, "||", "FUNCTION");
/*
* * The types aren't the same. The result of the operation is the *
* type of higher precedence.
*/
higherType = (leftTypeId.typePrecedence() >= rightTypeId
.typePrecedence()) ? leftType.getTypeName() : rightType
.getTypeName();
/* Get the length of the result */
resultLength = leftType.getMaximumWidth() + rightType.getMaximumWidth();
/*
* * Use following chart to handle overflow * operands CHAR(A) CHAR(B)
* and A+B <255 then result is CHAR(A+B) * operands CHAR FOR BIT DATA(A)
* CHAR FOR BIT DATA(B) and A+B <255 then result is CHAR FOR BIT
* DATA(A+B) * * operands CHAR(A) CHAR(B) and A+B>254 then result is
* VARCHAR(A+B) * operands CHAR FOR BIT DATA(A) CHAR FOR BIT DATA(B) and
* A+B>254 then result is VARCHAR FOR BIT DATA(A+B) * * operands CHAR(A)
* VARCHAR(B) and A+B <4001 then result is VARCHAR(A+B) * operands CHAR
* FOR BIT DATA(A) VARCHAR FOR BIT DATA(B) and A+B <4001 then result is
* VARCHAR FOR BIT DATA(A+B) * * operands CHAR(A) VARCHAR(B) and
* A+B>4000 then result is LONG VARCHAR * operands CHAR FOR BIT DATA(A)
* VARCHAR FOR BIT DATA(B) and A+B>4000 then result is LONG VARCHAR FOR
* BIT DATA * * operands CHAR(A) LONG VARCHAR then result is LONG
* VARCHAR * operands CHAR FOR BIT DATA(A) LONG VARCHAR FOR BIT DATA
* then result is LONG VARCHAR FOR BIT DATA * * operands VARCHAR(A)
* VARCHAR(B) and A+B <4001 then result is VARCHAR(A+B) * operands
* VARCHAR FOR BIT DATA(A) VARCHAR FOR BIT DATA(B) and A+B <4001 then
* result is VARCHAR FOR BIT DATA(A+B) * * operands VARCHAR(A)
* VARCHAR(B) and A+B>4000 then result is LONG VARCHAR * operands
* VARCHAR FOR BIT DATA(A) VARCHAR FOR BIT DATA(B) and A+B>4000 then
* result is LONG VARCHAR FOR BIT DATA * * operands VARCHAR(A) LONG
* VARCHAR then result is LONG VARCHAR * operands VARCHAR FOR BIT
* DATA(A) LONG VARCHAR FOR BIT DATA then result is LONG VARCHAR FOR BIT
* DATA * * operands LONG VARCHAR, LONG VARCHAR then result is LONG
* VARCHAR * operands LONG VARCHAR FOR BIT DATA, LONG VARCHAR FOR BIT
* DATA then result is LONG VARCHAR FOR BIT DATA * * operands CLOB(A),
* CHAR(B) then result is CLOB(MIN(A+B,2G)) * operands CLOB(A),
* VARCHAR(B) then result is CLOB(MIN(A+B,2G)) * operands CLOB(A), LONG
* VARCHAR then result is CLOB(MIN(A+32K,2G)) * operands CLOB(A),
* CLOB(B) then result is CLOB(MIN(A+B,2G)) * * operands BLOB(A), CHAR
* FOR BIT DATA(B) then result is BLOB(MIN(A+B,2G)) * operands BLOB(A),
* VARCHAR FOR BIT DATA(B) then result is BLOB(MIN(A+B,2G)) * operands
* BLOB(A), LONG VARCHAR FOR BIT DATA then result is BLOB(MIN(A+32K,2G)) *
* operands BLOB(A), BLOB(B) then result is BLOB(MIN(A+B,2G)) * *
* operands CHAR(A)/VARCHAR(A)/LONGVARCHAR, LONGVARCHAR and
* "concatenated string length">32700 does not cause automatic
* escalation * to LOB for compatibility with previous releases. Any
* such cases would result in an error at runtime *
*/
//in the following code, I can assume that left and right operands both
// will be either char kind
//of datatypes or they will be both binary kind of datatypes. That's
// because operand datatypes
//mismatch has already been handled earlier
if (leftTypeId.getJDBCTypeId() == Types.CHAR
|| leftTypeId.getJDBCTypeId() == Types.BINARY) {
switch (rightTypeId.getJDBCTypeId()) {
case Types.CHAR:
case Types.BINARY:
if (resultLength > Limits.DB2_CHAR_MAXWIDTH) {
if (rightTypeId.getJDBCTypeId() == Types.CHAR)
//operands CHAR(A) CHAR(B) and A+B>254 then result is
// VARCHAR(A+B)
higherType = TypeId.VARCHAR_NAME;
else
//operands CHAR FOR BIT DATA(A) CHAR FOR BIT DATA(B)
// and A+B>254 then result is VARCHAR FOR BIT DATA(A+B)
higherType = TypeId.VARBIT_NAME;
}
break;
case Types.VARCHAR:
case Types.VARBINARY:
if (resultLength > Limits.DB2_CONCAT_VARCHAR_LENGTH) {
if (rightTypeId.getJDBCTypeId() == Types.VARCHAR)
//operands CHAR(A) VARCHAR(B) and A+B>4000 then result
// is LONG VARCHAR
higherType = TypeId.LONGVARCHAR_NAME;
else
//operands CHAR FOR BIT DATA(A) VARCHAR FOR BIT DATA(B)
// and A+B>4000 then result is LONG VARCHAR FOR BIT DATA
higherType = TypeId.LONGVARBIT_NAME;
}
break;
case Types.CLOB:
case Types.BLOB:
//operands CHAR(A), CLOB(B) then result is CLOB(MIN(A+B,2G))
//operands CHAR FOR BIT DATA(A), BLOB(B) then result is
// BLOB(MIN(A+B,2G))
resultLength = clobBlobHandling(rightType, leftType);
break;
}
} else if (leftTypeId.getJDBCTypeId() == Types.VARCHAR) {
switch (rightTypeId.getJDBCTypeId()) {
case Types.CHAR: //operands CHAR(A) VARCHAR(B) and A+B>4000 then
// result is LONG VARCHAR
case Types.VARCHAR: //operands VARCHAR(A) VARCHAR(B) and A+B>4000
// then result is LONG VARCHAR
if (resultLength > Limits.DB2_CONCAT_VARCHAR_LENGTH)
higherType = TypeId.LONGVARCHAR_NAME;
break;
case Types.CLOB:
//operands VARCHAR(A), CLOB(B) then result is CLOB(MIN(A+B,2G))
resultLength = clobBlobHandling(rightType, leftType);
break;
}
} else if (leftTypeId.getJDBCTypeId() == Types.VARBINARY) {
switch (rightTypeId.getJDBCTypeId()) {
case Types.BINARY: //operands CHAR FOR BIT DATA(A) VARCHAR FOR BIT
// DATA(B) and A+B>4000 then result is LONG
// VARCHAR FOR BIT DATA
case Types.VARBINARY://operands VARCHAR FOR BIT DATA(A) VARCHAR FOR
// BIT DATA(B) and A+B>4000 then result is LONG
// VARCHAR FOR BIT DATA
if (resultLength > Limits.DB2_CONCAT_VARCHAR_LENGTH)
higherType = TypeId.LONGVARBIT_NAME;
break;
case Types.BLOB:
//operands VARCHAR FOR BIT DATA(A), BLOB(B) then result is
// BLOB(MIN(A+B,2G))
resultLength = clobBlobHandling(rightType, leftType);
break;
}
} else if (leftTypeId.getJDBCTypeId() == Types.CLOB
|| leftTypeId.getJDBCTypeId() == Types.BLOB) {
//operands CLOB(A), CHAR(B) then result is CLOB(MIN(A+B,2G))
//operands CLOB(A), VARCHAR(B) then result is CLOB(MIN(A+B,2G))
//operands CLOB(A), LONG VARCHAR then result is CLOB(MIN(A+32K,2G))
//operands CLOB(A), CLOB(B) then result is CLOB(MIN(A+B,2G))
//operands BLOB(A), CHAR FOR BIT DATA(B) then result is
// BLOB(MIN(A+B,2G))
//operands BLOB(A), VARCHAR FOR BIT DATA(B) then result is
// BLOB(MIN(A+B,2G))
//operands BLOB(A), LONG VARCHAR FOR BIT DATA then result is
// BLOB(MIN(A+32K,2G))
//operands BLOB(A), BLOB(B) then result is BLOB(MIN(A+B,2G))
resultLength = clobBlobHandling(leftType, rightType);
} else if (rightTypeId.getJDBCTypeId() == Types.CLOB
|| rightTypeId.getJDBCTypeId() == Types.BLOB) {
//operands LONG VARCHAR, CLOB(A) then result is CLOB(MIN(A+32K,2G))
//operands LONG VARCHAR FOR BIT DATA, BLOB(A) then result is
// BLOB(MIN(A+32K,2G))
resultLength = clobBlobHandling(rightType, leftType);
}
//bug - 5837. long varchar and long binary can't hold more data than
// their specific limits. If this length is violated by resulting
//concatenated string, an exception will be thrown at execute time.
if (higherType.equals(TypeId.LONGVARCHAR_NAME))
resultLength = TypeId.LONGVARCHAR_MAXWIDTH;
else if (higherType.equals(TypeId.LONGVARBIT_NAME))
resultLength = TypeId.LONGVARBIT_MAXWIDTH;
/*
* * Result Length can't be negative
*/
if (SanityManager.DEBUG) {
if (resultLength < 0) {
SanityManager
.THROWASSERT("There should not be an overflow of maximum length for any result type at this point. Overflow for BLOB/CLOB has already been handled earlier");
}
}
/* The result is nullable if either side is nullable */
nullable = leftType.isNullable() || rightType.isNullable();
/*
* * Create a new DataTypeDescriptor that has the correct * type and
* nullability. * * It's OK to call the implementation of the
* DataTypeDescriptorFactory * here, because we're in the same package.
*/
DataTypeDescriptor returnDTD = new DataTypeDescriptor(TypeId
.getBuiltInTypeId(higherType), nullable, resultLength);
//Check if collation derivations and collation types of 2 operands
//match?
//If they do, then the result of the concatenation will get the smae
//collation information. But if not, then the collation derivation of
//the result will be NONE.
if (leftType.getCollationDerivation() != rightType
.getCollationDerivation()
|| leftType.getCollationType() != rightType.getCollationType())
returnDTD = returnDTD.getCollatedType(
returnDTD.getCollationDerivation(),
StringDataValue.COLLATION_DERIVATION_NONE);
else {
returnDTD = returnDTD.getCollatedType(
leftType.getCollationType(),
leftType.getCollationDerivation());
}
return returnDTD;
}
/*
* for conatenation operator, we generate code as follows field = method(p1,
* p2, field); what we are ensuring here is if field is null then initialize
* it to NULL SQLxxx type. Because of the following, at execution time,
* SQLxxx concatenate method do not have to worry about field coming in as
* null
*/
protected void initializeResultField(ExpressionClassBuilder acb,
MethodBuilder mb, LocalField resultField) throws StandardException {
mb.conditionalIfNull();//get the field on the stack and if it is null
acb.generateNull(mb, getTypeCompiler(), getTypeServices()
.getCollationType());// yes, it is, hence create a NULL SQLxxx
// type object and put that on stack
mb.startElseCode(); //no, it is not null
mb.getField(resultField); //so put it back on the stack
mb.completeConditional(); //complete if else block
}
private static int clobBlobHandling(DataTypeDescriptor clobBlobType,
DataTypeDescriptor otherType) throws StandardException {
int resultLength;
if (otherType.getTypeId().getJDBCTypeId() == Types.LONGVARCHAR
|| otherType.getTypeId().getJDBCTypeId() == Types.LONGVARBINARY) {
//operands CLOB(A), LONG VARCHAR then result is CLOB(MIN(A+32K,2G))
//operands BLOB(A), LONG VARCHAR FOR BIT DATA then result is
// BLOB(MIN(A+32K,2G))
resultLength = clobBlobType.getMaximumWidth() + 32768;
} else {
//operands CLOB(A), CHAR(B) then result is CLOB(MIN(A+B,2G))
//operands CLOB(A), VARCHAR(B) then result is CLOB(MIN(A+B,2G))
//operands CLOB(A), CLOB(B) then result is CLOB(MIN(A+B,2G))
//operands BLOB(A), CHAR FOR BIT DATA(B) then result is
// BLOB(MIN(A+B,2G))
//operands BLOB(A), VARCHAR FOR BIT DATA(B) then result is
// BLOB(MIN(A+B,2G))
//operands BLOB(A), BLOB(B) then result is BLOB(MIN(A+B,2G))
resultLength = clobBlobType.getMaximumWidth()
+ otherType.getMaximumWidth();
}
if (resultLength < 1) //this mean A+B or A+32K is bigger than 2G
return (Integer.MAX_VALUE);
else
return (resultLength);
}
}