/*
Derby - Class org.apache.derby.iapi.types.DataTypeDescriptor
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.iapi.types;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.sql.Types;
import java.text.RuleBasedCollator;
import org.apache.derby.catalog.TypeDescriptor;
import org.apache.derby.catalog.types.TypeDescriptorImpl;
import org.apache.derby.iapi.error.StandardException;
import org.apache.derby.iapi.reference.SQLState;
import org.apache.derby.iapi.services.io.Formatable;
import org.apache.derby.iapi.services.io.StoredFormatIds;
import org.apache.derby.iapi.services.loader.ClassFactory;
import org.apache.derby.iapi.services.loader.ClassInspector;
import org.apache.derby.iapi.services.sanity.SanityManager;
import org.apache.derby.iapi.sql.conn.ConnectionUtil;
/**
* This is an implementation of DataTypeDescriptor from the generic language
* datatype module interface.
*
* @version 1.0
*/
public final class DataTypeDescriptor implements TypeDescriptor, Formatable
{
/********************************************************
**
** This class implements Formatable. That means that it
** can write itself to and from a formatted stream. If
** you add more fields to this class, make sure that you
** also write/read them with the writeExternal()/readExternal()
** methods.
**
** If, inbetween releases, you add more fields to this class,
** then you should bump the version number emitted by the getTypeFormatId()
** method.
**
********************************************************/
/*
** Static creators
*/
/**
* Get a descriptor that corresponds to a builtin JDBC type.
*
* @param jdbcType The int type of the JDBC type for which to get
* a corresponding SQL DataTypeDescriptor
*
* @return A new DataTypeDescriptor that corresponds to the Java type.
* A null return value means there is no corresponding SQL type
*/
public static DataTypeDescriptor getBuiltInDataTypeDescriptor
(
int jdbcType
)
{
return DataTypeDescriptor.getBuiltInDataTypeDescriptor(jdbcType, true);
}
public static DataTypeDescriptor getBuiltInDataTypeDescriptor
(
int jdbcType,
int length
)
{
return DataTypeDescriptor.getBuiltInDataTypeDescriptor(jdbcType, true, length);
}
/**
* Get a descriptor that corresponds to a builtin JDBC type.
*
* @param jdbcType The int type of the JDBC type for which to get
* a corresponding SQL DataTypeDescriptor
* @param isNullable TRUE means it could contain NULL, FALSE means
* it definitely cannot contain NULL.
*
* @return A new DataTypeDescriptor that corresponds to the Java type.
* A null return value means there is no corresponding SQL type
*/
public static DataTypeDescriptor getBuiltInDataTypeDescriptor
(
int jdbcType,
boolean isNullable
)
{
TypeId typeId = TypeId.getBuiltInTypeId(jdbcType);
if (typeId == null)
{
return null;
}
return new DataTypeDescriptor(typeId, isNullable);
}
/**
* Get a descriptor that corresponds to a builtin JDBC type.
*
* @param jdbcType The int type of the JDBC type for which to get
* a corresponding SQL DataTypeDescriptor
* @param isNullable TRUE means it could contain NULL, FALSE means
* it definitely cannot contain NULL.
*
* @return A new DataTypeDescriptor that corresponds to the Java type.
* A null return value means there is no corresponding SQL type
*/
public static DataTypeDescriptor getBuiltInDataTypeDescriptor
(
int jdbcType,
boolean isNullable,
int maxLength
)
{
TypeId typeId = TypeId.getBuiltInTypeId(jdbcType);
if (typeId == null)
{
return null;
}
return new DataTypeDescriptor(typeId, isNullable, maxLength);
}
/**
* Get a DataTypeServices that corresponds to a builtin SQL type
*
* @param sqlTypeName The name of the type for which to get
* a corresponding SQL DataTypeDescriptor
*
* @return A new DataTypeDescriptor that corresponds to the Java type.
* A null return value means there is no corresponding SQL type (only for 'char')
*/
public static DataTypeDescriptor getBuiltInDataTypeDescriptor
(
String sqlTypeName
)
{
return new DataTypeDescriptor(TypeId.getBuiltInTypeId(sqlTypeName), true);
}
/**
* Get a DataTypeServices that corresponds to a builtin SQL type
*
* @param sqlTypeName The name of the type for which to get
* a corresponding SQL DataTypeDescriptor
*
* @return A new DataTypeDescriptor that corresponds to the Java type.
* A null return value means there is no corresponding SQL type (only for 'char')
*/
public static DataTypeDescriptor getBuiltInDataTypeDescriptor
(
String sqlTypeName,
int length
)
{
return new DataTypeDescriptor(TypeId.getBuiltInTypeId(sqlTypeName), true, length);
}
/**
* Get a DataTypeServices that corresponds to a Java type
*
* @param javaTypeName The name of the Java type for which to get
* a corresponding SQL DataTypeDescriptor
*
* @return A new DataTypeDescriptor that corresponds to the Java type.
* A null return value means there is no corresponding SQL type (only for 'char')
*/
public static DataTypeDescriptor getSQLDataTypeDescriptor
(
String javaTypeName
)
{
return DataTypeDescriptor.getSQLDataTypeDescriptor(javaTypeName, true);
}
/**
* Get a DataTypeServices that corresponds to a Java type
*
* @param javaTypeName The name of the Java type for which to get
* a corresponding SQL DataTypeDescriptor
* @param isNullable TRUE means it could contain NULL, FALSE means
* it definitely cannot contain NULL.
*
* @return A new DataTypeDescriptor that corresponds to the Java type.
* A null return value means there is no corresponding SQL type (only for 'char')
*/
public static DataTypeDescriptor getSQLDataTypeDescriptor
(
String javaTypeName,
boolean isNullable
)
{
TypeId typeId = TypeId.getSQLTypeForJavaType(javaTypeName);
if (typeId == null)
{
return null;
}
return new DataTypeDescriptor(typeId, isNullable);
}
/**
* Get a DataTypeDescriptor that corresponds to a Java type
*
* @param javaTypeName The name of the Java type for which to get
* a corresponding SQL DataTypeDescriptor
* @param precision The number of decimal digits
* @param scale The number of digits after the decimal point
* @param isNullable TRUE means it could contain NULL, FALSE means
* it definitely cannot contain NULL.
* @param maximumWidth The maximum width of a data value
* represented by this type.
*
* @return A new DataTypeDescriptor that corresponds to the Java type.
* A null return value means there is no corresponding SQL type.
*/
public static DataTypeDescriptor getSQLDataTypeDescriptor
(
String javaTypeName,
int precision,
int scale,
boolean isNullable,
int maximumWidth
)
{
TypeId typeId = TypeId.getSQLTypeForJavaType(javaTypeName);
if (typeId == null)
{
return null;
}
return new DataTypeDescriptor(typeId,
precision,
scale,
isNullable,
maximumWidth);
}
/*
** Instance fields & methods
*/
private TypeDescriptorImpl typeDescriptor;
private TypeId typeId;
/**
* Public niladic constructor. Needed for Formatable interface to work.
*
*/
public DataTypeDescriptor() {}
/**
* Constructor for use with numeric types
*
* @param typeId The typeId of the type being described
* @param precision The number of decimal digits.
* @param scale The number of digits after the decimal point.
* @param isNullable TRUE means it could contain NULL, FALSE means
* it definitely cannot contain NULL.
* @param maximumWidth The maximum number of bytes for this datatype
*/
public DataTypeDescriptor(TypeId typeId, int precision, int scale,
boolean isNullable, int maximumWidth)
{
this.typeId = typeId;
typeDescriptor = new TypeDescriptorImpl(typeId.getBaseTypeId(),
precision,
scale,
isNullable,
maximumWidth);
}
/**
* Constructor to use when the caller doesn't know if it is requesting
* numeric or no-numeric DTD. For instance, when dealing with MAX/MIN
* aggregrate operators, AggregateNode.bindExpression could be dealing
* with a character string operand or a numeric operand. The result of
* MAX/MIN will depend on the type of it's operand. And hence when this
* constructor gets called by AggregateNode.bindExpression, we don't know
* what type we are constructing and hence this constructor supports
* arguments for both numeric and non-numeric types.
*
* @param typeId The typeId of the type being described
* @param precision The number of decimal digits.
* @param scale The number of digits after the decimal point.
* @param isNullable TRUE means it could contain NULL, FALSE means
* it definitely cannot contain NULL.
* @param maximumWidth The maximum number of bytes for this datatype
* @param collationType The collation type of a string data type
* @param collationDerivation Collation Derivation of a string data type
*/
public DataTypeDescriptor(TypeId typeId, int precision, int scale,
boolean isNullable, int maximumWidth, int collationType,
int collationDerivation)
{
this.typeId = typeId;
typeDescriptor = new TypeDescriptorImpl(typeId.getBaseTypeId(),
precision,
scale,
isNullable,
maximumWidth,
collationType,
collationDerivation);
}
/**
* Constructor for use with non-numeric types
*
* @param typeId The typeId of the type being described
* @param isNullable TRUE means it could contain NULL, FALSE means
* it definitely cannot contain NULL.
* @param maximumWidth The maximum number of bytes for this datatype
*/
public DataTypeDescriptor(TypeId typeId, boolean isNullable,
int maximumWidth)
{
this.typeId = typeId;
typeDescriptor = new TypeDescriptorImpl(typeId.getBaseTypeId(),
isNullable,
maximumWidth);
}
public DataTypeDescriptor(TypeId typeId, boolean isNullable) {
this.typeId = typeId;
typeDescriptor = new TypeDescriptorImpl(typeId.getBaseTypeId(),
typeId.getMaximumPrecision(),
typeId.getMaximumScale(),
isNullable,
typeId.getMaximumMaximumWidth());
}
public DataTypeDescriptor(DataTypeDescriptor source, boolean isNullable)
{
//There might be other places, but one place this method gets called
//from is ResultColumn.init. When the ResultColumn(RC) is for a
//ColumnDescriptor(CD), the RC's TypeDescriptorImpl(TDI) should get
//all the attributes of CD's TDI. So, if the CD is for a user table's
//character type column, then this call by RC.init should have CD's
//collation attributes copied into RC along with other attributes.
this.typeId = source.typeId;
typeDescriptor = new TypeDescriptorImpl(source.typeDescriptor,
source.getPrecision(),
source.getScale(),
isNullable,
source.getMaximumWidth(),
source.getCollationType(),
source.getCollationDerivation());
}
/**
* Constructor for internal uses only.
* (This is useful when the precision and scale are potentially wider than
* those in the source, like when determining the dominant data type.)
*
* @param source The DTSI to copy
* @param precision The number of decimal digits.
* @param scale The number of digits after the decimal point.
* @param isNullable TRUE means it could contain NULL, FALSE means
* it definitely cannot contain NULL.
* @param maximumWidth The maximum number of bytes for this datatype
*/
public DataTypeDescriptor(DataTypeDescriptor source,
int precision,
int scale,
boolean isNullable,
int maximumWidth)
{
this.typeId = source.typeId;
typeDescriptor = new TypeDescriptorImpl(source.typeDescriptor,
precision,
scale,
isNullable,
maximumWidth,
source.getCollationType(),
source.getCollationDerivation());
}
/**
* Constructor for internal uses only
*
* @param source The DTSI to copy
* @param isNullable TRUE means it could contain NULL, FALSE means
* it definitely cannot contain NULL.
* @param maximumWidth The maximum number of bytes for this datatype
*/
public DataTypeDescriptor(DataTypeDescriptor source, boolean isNullable,
int maximumWidth)
{
this.typeId = source.typeId;
typeDescriptor = new TypeDescriptorImpl(source.typeDescriptor,
source.getPrecision(),
source.getScale(),
isNullable,
maximumWidth,
source.getCollationType(),
source.getCollationDerivation());
}
/**
* Constructor for use in reconstructing a DataTypeDescriptor from a
* TypeDescriptorImpl and a TypeId
*
* @param source The TypeDescriptorImpl to construct this DTSI from
*/
public DataTypeDescriptor(TypeDescriptorImpl source, TypeId typeId)
{
typeDescriptor = source;
this.typeId = typeId;;
}
/* DataTypeDescriptor Interface */
public DataValueDescriptor normalize(DataValueDescriptor source,
DataValueDescriptor cachedDest)
throws StandardException
{
if (SanityManager.DEBUG) {
if (cachedDest != null) {
if (!getTypeId().isUserDefinedTypeId()) {
String t1 = getTypeName();
String t2 = cachedDest.getTypeName();
if (!t1.equals(t2)) {
if (!(((t1.equals("DECIMAL") || t1.equals("NUMERIC"))
&& (t2.equals("DECIMAL") || t2.equals("NUMERIC"))) ||
(t1.startsWith("INT") && t2.startsWith("INT")))) //INT/INTEGER
SanityManager.THROWASSERT(
"Normalization of " + t2 + " being asked to convert to " + t1);
}
}
}
}
if (source.isNull())
{
if (!isNullable())
throw StandardException.newException(SQLState.LANG_NULL_INTO_NON_NULL,"");
if (cachedDest == null)
cachedDest = getNull();
else
cachedDest.setToNull();
} else {
if (cachedDest == null)
cachedDest = getNull();
int jdbcId = getJDBCTypeId();
cachedDest.normalize(this, source);
//doing the following check after normalize so that normalize method would get called on long varchs and long varbinary
//Need normalize to be called on long varchar for bug 5592 where we need to enforce a lenght limit in db2 mode
if ((jdbcId == Types.LONGVARCHAR) || (jdbcId == Types.LONGVARBINARY)) {
// special case for possible streams
if (source.getClass() == cachedDest.getClass())
return source;
}
}
return cachedDest;
}
/**
* Get the dominant type (DataTypeDescriptor) of the 2.
* For variable length types, the resulting type will have the
* biggest max length of the 2.
* If either side is nullable, then the result will also be nullable.
*
* If dealing with character string types, then make sure to set the
* collation info on the dominant type. Following algorithm will be used
* for dominant DTD's collation determination. Each of the steps of the
* algorithm have been numbered in the comments below and those same
* numbers are used in the actual algorithm below so it is easier to
* understand and maintain.
*
* Step 1
* If the DTD for "this" node has the same collation derivation as the
* otherDTS, then check if their collation types match too. If the
* collation types match too, then DTD for dominant type will get the same
* collation derivation and type.
*
* Step 2
* If the collation derivation for DTD for "this" node and otherDTS do not
* match, then check if one of them has the collation derivation of NONE.
* If that is the case, then dominant DTD will get the collation type and
* derivation of DTD whose collation derivation is not NONE.
*
* Step 3
* If the collation derivation for DTD for "this" node and otherDTS do not
* match, and none of them have the derivation of NONE then it means that
* we are dealing with collation derivation of IMPLICIT and EXPLICIT and
* hence the dominant DTD should get collation derivation of NONE. This is
* not a possibility in Derby 10.3 because the only 2 possible collation
* derivation supported are IMPLICIT and NONE.
*
* Step 4
* If the collation derivation for DTD for "this" node and otherDTS match,
* then check if the collation types match too. If not, then the dominant
* DTD should get collation derivation of NONE.
*
* @param otherDTS DataTypeDescriptor to compare with.
* @param cf A ClassFactory
*
* @return DataTypeDescriptor DTS for dominant type
*
* @exception StandardException Thrown on error
*/
public DataTypeDescriptor getDominantType(DataTypeDescriptor otherDTS, ClassFactory cf)
throws StandardException
{
boolean nullable;
TypeId thisType;
TypeId otherType;
DataTypeDescriptor higherType = null;
DataTypeDescriptor lowerType = null;
int maximumWidth;
int precision = getPrecision();
int scale = getScale();
thisType = getTypeId();
otherType = otherDTS.getTypeId();
/* The result is nullable if either side is nullable */
nullable = isNullable() || otherDTS.isNullable();
/*
** The result will have the maximum width of both sides
*/
maximumWidth = (getMaximumWidth() > otherDTS.getMaximumWidth())
? getMaximumWidth() : otherDTS.getMaximumWidth();
/* We need 2 separate methods of determining type dominance - 1 if both
* types are system built-in types and the other if at least 1 is
* a user type. (typePrecedence is meaningless for user types.)
*/
if (!thisType.userType() && !otherType.userType())
{
TypeId higherTypeId;
TypeId lowerTypeId;
if (thisType.typePrecedence() > otherType.typePrecedence())
{
higherType = this;
lowerType = otherDTS;
higherTypeId = thisType;
lowerTypeId = otherType;
}
else
{
higherType = otherDTS;
lowerType = this;
higherTypeId = otherType;
lowerTypeId = thisType;
}
//Following is checking if higher type argument is real and other argument is decimal/bigint/integer/smallint,
//then result type should be double
if (higherTypeId.isRealTypeId() && (!lowerTypeId.isRealTypeId()) && lowerTypeId.isNumericTypeId())
{
higherType = DataTypeDescriptor.getBuiltInDataTypeDescriptor(Types.DOUBLE);
higherTypeId = TypeId.getBuiltInTypeId(Types.DOUBLE);
}
/*
** If we have a DECIMAL/NUMERIC we have to do some
** extra work to make sure the resultant type can
** handle the maximum values for the two input
** types. We cannot just take the maximum for
** precision. E.g. we want something like:
**
** DEC(10,10) and DEC(3,0) => DEC(13,10)
**
** (var)char type needs some conversion handled later.
*/
if (higherTypeId.isDecimalTypeId() && (!lowerTypeId.isStringTypeId()))
{
precision = higherTypeId.getPrecision(this, otherDTS);
if (precision > 31) precision = 31; //db2 silently does this and so do we
scale = higherTypeId.getScale(this, otherDTS);
/* maximumWidth needs to count possible leading '-' and
* decimal point and leading '0' if scale > 0. See also
* sqlgrammar.jj(exactNumericType). Beetle 3875
*/
maximumWidth = (scale > 0) ? precision + 3 : precision + 1;
}
else if (thisType.typePrecedence() != otherType.typePrecedence())
{
precision = higherType.getPrecision();
scale = higherType.getScale();
/* GROSS HACKS:
* If we are doing an implicit (var)char->(var)bit conversion
* then the maximum width for the (var)char as a (var)bit
* is really 16 * its width as a (var)char. Adjust
* maximumWidth accordingly.
* If we are doing an implicit (var)char->decimal conversion
* then we need to increment the decimal's precision by
* 2 * the maximum width for the (var)char and the scale
* by the maximum width for the (var)char. The maximumWidth
* becomes the new precision + 3. This is because
* the (var)char could contain any decimal value from XXXXXX
* to 0.XXXXX. (In other words, we don't know which side of the
* decimal point the characters will be on.)
*/
if (lowerTypeId.isStringTypeId())
{
if (higherTypeId.isBitTypeId() &&
! (higherTypeId.isLongConcatableTypeId()))
{
if (lowerTypeId.isLongConcatableTypeId())
{
if (maximumWidth > (Integer.MAX_VALUE / 16))
maximumWidth = Integer.MAX_VALUE;
else
maximumWidth *= 16;
}
else
{
int charMaxWidth;
int fromWidth = lowerType.getMaximumWidth();
if (fromWidth > (Integer.MAX_VALUE / 16))
charMaxWidth = Integer.MAX_VALUE;
else
charMaxWidth = 16 * fromWidth;
maximumWidth = (maximumWidth >= charMaxWidth) ?
maximumWidth : charMaxWidth;
}
}
}
/*
* If we are doing an implicit (var)char->decimal conversion
* then the resulting decimal's precision could be as high as
* 2 * the maximum width (precisely 2mw-1) for the (var)char
* and the scale could be as high as the maximum width
* (precisely mw-1) for the (var)char.
* The maximumWidth becomes the new precision + 3. This is
* because the (var)char could contain any decimal value from
* XXXXXX to 0.XXXXX. (In other words, we don't know which
* side of the decimal point the characters will be on.)
*
* We don't follow this algorithm for long varchar because the
* maximum length of a long varchar is maxint, and we don't
* want to allocate a huge decimal value. So in this case,
* the precision, scale, and maximum width all come from
* the decimal type.
*/
if (lowerTypeId.isStringTypeId() &&
! (lowerTypeId.isLongConcatableTypeId()) &&
higherTypeId.isDecimalTypeId() )
{
int charMaxWidth = lowerType.getMaximumWidth();
int charPrecision;
/*
** Be careful not to overflow when calculating the
** precision. Remember that we will be adding
** three to the precision to get the maximum width.
*/
if (charMaxWidth > (Integer.MAX_VALUE - 3) / 2)
charPrecision = Integer.MAX_VALUE - 3;
else
charPrecision = charMaxWidth * 2;
if (precision < charPrecision)
precision = charPrecision;
if (scale < charMaxWidth)
scale = charMaxWidth;
maximumWidth = precision + 3;
}
}
}
else
{
/* At least 1 type is not a system built-in type */
ClassInspector cu = cf.getClassInspector();
TypeId thisCompType = (TypeId) thisType;
TypeId otherCompType = (TypeId) otherType;
if (cu.assignableTo(thisCompType.getCorrespondingJavaTypeName(),
otherCompType.getCorrespondingJavaTypeName()))
{
higherType = otherDTS;
}
else
{
if (SanityManager.DEBUG)
SanityManager.ASSERT(
cu.assignableTo(otherCompType.getCorrespondingJavaTypeName(),
thisCompType.getCorrespondingJavaTypeName()),
otherCompType.getCorrespondingJavaTypeName() +
" expected to be assignable to " +
thisCompType.getCorrespondingJavaTypeName());
higherType = this;
}
precision = higherType.getPrecision();
scale = higherType.getScale();
}
higherType = new DataTypeDescriptor(higherType,
precision, scale, nullable, maximumWidth);
//Set collation info on the DTD for dominant type if it is string type
//The algorithm used is explained in this method's javadoc
if (higherType.getTypeId().isStringTypeId()) {
if (getCollationDerivation() != otherDTS.getCollationDerivation()) {
if (getCollationDerivation() == StringDataValue.COLLATION_DERIVATION_NONE) {
//Step 2
higherType.setCollationDerivation(otherDTS.getCollationDerivation());
higherType.setCollationType(otherDTS.getCollationType());
} else if (otherDTS.getCollationDerivation() == StringDataValue.COLLATION_DERIVATION_NONE) {
//Step 2
higherType.setCollationDerivation(getCollationDerivation());
higherType.setCollationType(getCollationType());
} else {
//Step 3
higherType.setCollationDerivation(StringDataValue.COLLATION_DERIVATION_NONE);
}
} else if (getCollationType() != otherDTS.getCollationType())
//Step 4
higherType.setCollationDerivation(StringDataValue.COLLATION_DERIVATION_NONE);
else {
//Step 1
higherType.setCollationDerivation(getCollationDerivation());
higherType.setCollationType(getCollationType());
}
}
return higherType;
}
/**
* Check whether or not the 2 types (DataTypeDescriptor) have the same type
* and length.
* This is useful for UNION when trying to decide whether a NormalizeResultSet
* is required.
*
* @param otherDTS DataTypeDescriptor to compare with.
*
* @return boolean Whether or not the 2 DTSs have the same type and length.
*/
public boolean isExactTypeAndLengthMatch(DataTypeDescriptor otherDTS)
{
/* Do both sides have the same length? */
if (getMaximumWidth() != otherDTS.getMaximumWidth())
{
return false;
}
if (getScale() != otherDTS.getScale())
{
return false;
}
if (getPrecision() != otherDTS.getPrecision())
{
return false;
}
TypeId thisType = getTypeId();
TypeId otherType = otherDTS.getTypeId();
/* Do both sides have the same type? */
if ( ! thisType.equals(otherType))
{
return false;
}
return true;
}
/**
* @see TypeDescriptor#getMaximumWidth
*/
public int getMaximumWidth()
{
return typeDescriptor.getMaximumWidth();
}
/**
* @see TypeDescriptor#getMaximumWidthInBytes
*/
public int getMaximumWidthInBytes()
{
return typeDescriptor.getMaximumWidthInBytes();
}
/**
* Gets the TypeId for the datatype.
*
* @return The TypeId for the datatype.
*/
public TypeId getTypeId()
{
return typeId;
}
/**
Get a Null for this type.
*/
public DataValueDescriptor getNull() throws StandardException {
DataValueDescriptor returnDVD = typeId.getNull();
//If we are dealing with default collation, then we have got the
//right DVD already. Just return it.
if (typeDescriptor.getCollationType() == StringDataValue.COLLATION_TYPE_UCS_BASIC)
return returnDVD;
//If we are dealing with territory based collation and returnDVD is
//of type StringDataValue, then we need to return a StringDataValue
//with territory based collation.
if (returnDVD instanceof StringDataValue) {
try {
RuleBasedCollator rbs = ConnectionUtil.getCurrentLCC().getDataValueFactory().
getCharacterCollator(typeDescriptor.getCollationType());
return ((StringDataValue)returnDVD).getValue(rbs);
}
catch( java.sql.SQLException sqle)
{
throw StandardException.plainWrapException( sqle);
}
}
else
return returnDVD;
}
/**
* Gets the name of this datatype.
*
*
* @return the name of this datatype
*/
public String getTypeName()
{
return typeId.getSQLTypeName();
}
/**
* Get the jdbc type id for this type. JDBC type can be
* found in java.sql.Types.
*
* @return a jdbc type, e.g. java.sql.Types.DECIMAL
*
* @see Types
*/
public int getJDBCTypeId()
{
return typeId.getJDBCTypeId();
}
/**
* Returns the number of decimal digits for the datatype, if applicable.
*
* @return The number of decimal digits for the datatype. Returns
* zero for non-numeric datatypes.
*/
public int getPrecision()
{
return typeDescriptor.getPrecision();
}
/**
* Returns the number of digits to the right of the decimal for
* the datatype, if applicable.
*
* @return The number of digits to the right of the decimal for
* the datatype. Returns zero for non-numeric datatypes.
*/
public int getScale()
{
return typeDescriptor.getScale();
}
/** @see TypeDescriptor#getCollationType() */
public int getCollationType()
{
return typeDescriptor.getCollationType();
}
/**
* Gets the name of this datatype.
* <p>
* Used to generate strings decribing collation type for error messages.
*
*
* @return the name of the collation being used in this type.
*/
public String getCollationName()
{
return(typeDescriptor.getCollationName());
}
/**
* Set the collation type of this TypeDescriptor
* @param collationTypeValue This will be COLLATION_TYPE_UCS_BASIC
* or COLLATION_TYPE_TERRITORY_BASED
*
* @see StringDataValue#COLLATION_TYPE_UCS_BASIC
* @see StringDataValue#COLLATION_TYPE_TERRITORY_BASED
*/
public void setCollationType(int collationTypeValue)
{
typeDescriptor.setCollationType(collationTypeValue);
}
/** @see TypeDescriptor#getCollationDerivation() */
public int getCollationDerivation()
{
return typeDescriptor.getCollationDerivation();
}
/**
* Set the collation derivation of this DTD
* @param collationDerivationValue This will be
* COLLATION_DERIVATION_NONE/COLLATION_DERIVATION_IMPLICIT/COLLATION_DERIVATION_EXPLICIT
* In Derby 10.3, we do not expect to get value COLLATION_DERIVATION_EXPLICIT.
*
* @see StringDataValue#COLLATION_DERIVATION_NONE
* @see StringDataValue#COLLATION_DERIVATION_IMPLICIT
* @see StringDataValue#COLLATION_DERIVATION_EXPLICIT
*/
public void setCollationDerivation(int collationDerivationValue)
{
typeDescriptor.setCollationDerivation(collationDerivationValue);
}
/**
* Returns TRUE if the datatype can contain NULL, FALSE if not.
* JDBC supports a return value meaning "nullability unknown" -
* I assume we will never have columns where the nullability is unknown.
*
* @return TRUE if the datatype can contain NULL, FALSE if not.
*/
public boolean isNullable()
{
return typeDescriptor.isNullable();
}
/**
* Set the nullability of the datatype described by this descriptor
*
* @param nullable TRUE means set nullability to TRUE, FALSE
* means set it to FALSE
*/
public void setNullability(boolean nullable)
{
typeDescriptor.setNullability(nullable);
}
/**
* Return a type descriptor identical to the this type
* with the exception of its nullability. If the nullablity
* required matches the nullability of this then this is returned.
*
* @param isNullable True to return a nullable type, false otherwise.
*/
public DataTypeDescriptor getNullabilityType(boolean isNullable)
{
if (isNullable() == isNullable)
return this;
return new DataTypeDescriptor(this, isNullable);
}
/**
Compare if two TypeDescriptors are exactly the same
@param aTypeDescriptor the typeDescriptor to compare to.
*/
public boolean equals(Object aTypeDescriptor)
{
return typeDescriptor.equals(aTypeDescriptor);
}
/**
* Check if this type is comparable with the passed type.
*
* @param compareWithDTD the type of the instance to compare with this type.
* @param forEquals True if this is an = or <> comparison, false
* otherwise.
* @param cf A ClassFactory
* @return true if compareWithDTD is comparable to this type, else false.
*/
public boolean comparable(DataTypeDescriptor compareWithDTD,
boolean forEquals,
ClassFactory cf){
TypeId compareWithTypeID = compareWithDTD.getTypeId();
int compareWithJDBCTypeId = compareWithTypeID.getJDBCTypeId();
// Long types cannot be compared.
// XML types also fall in this window
// Says SQL/XML[2003] spec:
// 4.2.2 XML comparison and assignment
// "XML values are not comparable."
// An XML value cannot be compared to any type--
// not even to other XML values.
if (compareWithTypeID.isLongConcatableTypeId() || typeId.isLongConcatableTypeId())
return false;
// Ref types cannot be compared
if (typeId.isRefTypeId() || compareWithTypeID.isRefTypeId())
return false;
//If this DTD is not user defined type but the DTD to be compared with
//is user defined type, then let the other DTD decide what should be the
//outcome of the comparable method.
if (!(typeId.isUserDefinedTypeId()) &&
(compareWithTypeID.isUserDefinedTypeId()))
return compareWithDTD.comparable(this, forEquals, cf);
//Numeric types are comparable to numeric types, boolean types and to
//comparable user types
if (typeId.isNumericTypeId())
return (compareWithTypeID.isNumericTypeId() ||
compareWithTypeID.isBooleanTypeId());
//CHAR, VARCHAR and LONGVARCHAR are comparable to strings, boolean,
//DATE/TIME/TIMESTAMP and to comparable user types
if (typeId.isStringTypeId()) {
if((compareWithTypeID.isDateTimeTimeStampTypeID() ||
compareWithTypeID.isBooleanTypeId()))
return true;
//If both the types are string types, then we need to make sure
//they have the same collation set on them
if (compareWithTypeID.isStringTypeId() && typeId.isStringTypeId()) {
return compareCollationInfo(compareWithDTD);
} else
return false;//can't be compared
}
//Are comparable to other bit types and comparable user types
if (typeId.isBitTypeId())
return (compareWithTypeID.isBitTypeId());
//Booleans are comparable to Boolean, string, numeric and to
//comparable user types
if (typeId.isBooleanTypeId())
return (compareWithTypeID.getSQLTypeName().equals(typeId.getSQLTypeName()) ||
compareWithTypeID.isStringTypeId() ||
compareWithTypeID.isNumericTypeId());
//Dates are comparable to dates, strings and to comparable
//user types.
if (typeId.getJDBCTypeId() == Types.DATE)
if (compareWithJDBCTypeId == Types.DATE ||
compareWithTypeID.isStringTypeId())
return true;
else
return false;
//Times are comparable to times, strings and to comparable
//user types.
if (typeId.getJDBCTypeId() == Types.TIME)
if (compareWithJDBCTypeId == Types.TIME ||
compareWithTypeID.isStringTypeId())
return true;
else
return false;
//Timestamps are comparable to timestamps, strings and to
//comparable user types.
if (typeId.getJDBCTypeId() == Types.TIMESTAMP)
if (compareWithJDBCTypeId == Types.TIMESTAMP ||
compareWithTypeID.isStringTypeId())
return true;
else
return false;
//User types are comparable to other user types only if
//(for now) they are the same type and are being used to
//implement some JDBC type. This is sufficient for
//date/time types; it may be generalized later for e.g.
//comparison of any user type with one of its subtypes.
if (typeId.isUserDefinedTypeId() || typeId.getJDBCTypeId() == Types.OTHER) {
if (forEquals)
return true;
try {
Class thisClass = cf.getClassInspector().getClass(
typeId.getCorrespondingJavaTypeName());
return java.lang.Comparable.class.isAssignableFrom(thisClass);
} catch (ClassNotFoundException cnfe) {
return false;
}
}
return false;
}
/**
* Compare the collation info on this DTD with the passed DTD. The rules
* for comparison are as follows (these are as per SQL standard 2003
* Section 9.13)
*
* 1)If both the DTDs have collation derivation of NONE, then they can't be
* compared and we return false.
* 2)If both the DTDs have same collation derivation (which in Derby's case
* at this point will mean collation derivation of IMPLICIT), then check
* the collation types. If they match, then return true. If they do not
* match, then they can't be compared and hence return false.
* 3)If one DTD has collation derivation of IMPLICIT and other DTD has
* collation derivation of NONE, then 2 DTDs are comparable using the
* collation type of DTD with collation derivation of IMPLICIT. Derby does
* not implement this rule currently and it is being traked as DERBY-2678.
* Derby's current behavior is to throw an exception if both the DTDs
* involved in collation operation do not have collation derivation of
* IMPLICIT. This behavior is a subset of SQL standard.
* 4)Derby currently does not support collation derivation of EXPLICIT and
* hence we do not have the code to enforce rules as mentioned in Section
* 9.13 of SQL spec for collation derivation of EXPLICIT. When we implement
* collation derivation of EXPLICIT, we should make sure that we follow the
* rules as specified in the SQL spec for comparability.
*
* @param compareWithDTD compare this DTD's collation info
*
* @return value depends on the algorithm above.
*/
public boolean compareCollationInfo(DataTypeDescriptor compareWithDTD){
//both the operands can not have the collation derivation of
//NONE. This is because in that case, we do not know what kind
//of collation to use for comparison.
if (getCollationDerivation() == compareWithDTD.getCollationDerivation() &&
getCollationDerivation() == StringDataValue.COLLATION_DERIVATION_NONE)
return false;
if (getCollationDerivation() == compareWithDTD.getCollationDerivation() &&
getCollationType() == compareWithDTD.getCollationType())
return true;//collation matches
else
return false;//collation does not match
}
/**
* Converts this data type descriptor (including length/precision)
* to a string. E.g.
*
* VARCHAR(30)
*
* or
*
* java.util.Hashtable
*
* @return String version of datatype, suitable for running through
* the Parser.
*/
public String getSQLstring()
{
return typeId.toParsableString( this );
}
/**
* Get the simplified type descriptor that is intended to be stored
* in the system tables.
*/
public TypeDescriptorImpl getCatalogType()
{
return typeDescriptor;
}
/**
* Get the estimated memory usage for this type descriptor.
*/
public double estimatedMemoryUsage() {
switch (typeId.getTypeFormatId())
{
case StoredFormatIds.LONGVARBIT_TYPE_ID:
/* Who knows? Let's just use some big number */
return 10000.0;
case StoredFormatIds.BIT_TYPE_ID:
return (double) ( ( ((float) getMaximumWidth()) / 8.0) + 0.5);
case StoredFormatIds.BOOLEAN_TYPE_ID:
return 4.0;
case StoredFormatIds.CHAR_TYPE_ID:
case StoredFormatIds.VARCHAR_TYPE_ID:
case StoredFormatIds.NATIONAL_CHAR_TYPE_ID:
case StoredFormatIds.NATIONAL_VARCHAR_TYPE_ID:
return (double) (2.0 * getMaximumWidth());
case StoredFormatIds.LONGVARCHAR_TYPE_ID:
case StoredFormatIds.NATIONAL_LONGVARCHAR_TYPE_ID:
/* Who knows? Let's just use some big number */
return 10000.0;
case StoredFormatIds.DECIMAL_TYPE_ID:
/*
** 0.415 converts from number decimal digits to number of 8-bit digits.
** Add 1.0 for the sign byte, and 0.5 to force it to round up.
*/
return (double) ( (getPrecision() * 0.415) + 1.5 );
case StoredFormatIds.DOUBLE_TYPE_ID:
return 8.0;
case StoredFormatIds.INT_TYPE_ID:
return 4.0;
case StoredFormatIds.LONGINT_TYPE_ID:
return 8.0;
case StoredFormatIds.REAL_TYPE_ID:
return 4.0;
case StoredFormatIds.SMALLINT_TYPE_ID:
return 2.0;
case StoredFormatIds.TINYINT_TYPE_ID:
return 1.0;
case StoredFormatIds.REF_TYPE_ID:
/* I think 12 is the right number */
return 12.0;
case StoredFormatIds.USERDEFINED_TYPE_ID_V3:
if (typeId.userType()) {
/* Who knows? Let's just use some medium-sized number */
return 256.0;
}
case StoredFormatIds.DATE_TYPE_ID:
case StoredFormatIds.TIME_TYPE_ID:
case StoredFormatIds.TIMESTAMP_TYPE_ID:
return 12.0;
default:
return 0.0;
}
}
/**
* Compare JdbcTypeIds to determine if they represent equivalent
* SQL types. For example Types.NUMERIC and Types.DECIMAL are
* equivalent
*
* @param existingType JDBC type id of Derby data type
* @param jdbcTypeId JDBC type id passed in from application.
*
* @return boolean true if types are equivalent, false if not
*/
public static boolean isJDBCTypeEquivalent(int existingType, int jdbcTypeId)
{
// Any type matches itself.
if (existingType == jdbcTypeId)
return true;
// To a numeric type
if (DataTypeDescriptor.isNumericType(existingType)) {
if (DataTypeDescriptor.isNumericType(jdbcTypeId))
return true;
if (DataTypeDescriptor.isCharacterType(jdbcTypeId))
return true;
return false;
}
// To character type.
if (DataTypeDescriptor.isCharacterType(existingType)) {
if (DataTypeDescriptor.isCharacterType(jdbcTypeId))
return true;
if (DataTypeDescriptor.isNumericType(jdbcTypeId))
return true;
switch (jdbcTypeId) {
case Types.DATE:
case Types.TIME:
case Types.TIMESTAMP:
return true;
default:
break;
}
return false;
}
// To binary type
if (DataTypeDescriptor.isBinaryType(existingType)) {
if (DataTypeDescriptor.isBinaryType(jdbcTypeId))
return true;
return false;
}
// To DATE, TIME
if (existingType == Types.DATE || existingType == Types.TIME) {
if (DataTypeDescriptor.isCharacterType(jdbcTypeId))
return true;
if (jdbcTypeId == Types.TIMESTAMP)
return true;
return false;
}
// To TIMESTAMP
if (existingType == Types.TIMESTAMP) {
if (DataTypeDescriptor.isCharacterType(jdbcTypeId))
return true;
if (jdbcTypeId == Types.DATE)
return true;
return false;
}
// To CLOB
if (existingType == Types.CLOB && DataTypeDescriptor.isCharacterType(jdbcTypeId))
return true;
return false;
}
public static boolean isNumericType(int jdbcType) {
switch (jdbcType) {
case Types.BIT:
case org.apache.derby.iapi.reference.JDBC30Translation.SQL_TYPES_BOOLEAN:
case Types.TINYINT:
case Types.SMALLINT:
case Types.INTEGER:
case Types.BIGINT:
case Types.REAL:
case Types.FLOAT:
case Types.DOUBLE:
case Types.DECIMAL:
case Types.NUMERIC:
return true;
default:
return false;
}
}
/**
* Check whether a JDBC type is one of the character types that are
* compatible with the Java type <code>String</code>.
*
* <p><strong>Note:</strong> <code>CLOB</code> is not compatible with
* <code>String</code>. See tables B-4, B-5 and B-6 in the JDBC 3.0
* Specification.
*
* <p> There are some non-character types that are compatible with
* <code>String</code> (examples: numeric types, binary types and
* time-related types), but they are not covered by this method.
*
* @param jdbcType a JDBC type
* @return <code>true</code> iff <code>jdbcType</code> is a character type
* and compatible with <code>String</code>
* @see java.sql.Types
*/
private static boolean isCharacterType(int jdbcType) {
switch (jdbcType) {
case Types.CHAR:
case Types.VARCHAR:
case Types.LONGVARCHAR:
return true;
default:
return false;
}
}
/**
* Check whether a JDBC type is compatible with the Java type
* <code>byte[]</code>.
*
* <p><strong>Note:</strong> <code>BLOB</code> is not compatible with
* <code>byte[]</code>. See tables B-4, B-5 and B-6 in the JDBC 3.0
* Specification.
*
* @param jdbcType a JDBC type
* @return <code>true</code> iff <code>jdbcType</code> is compatible with
* <code>byte[]</code>
* @see java.sql.Types
*/
private static boolean isBinaryType(int jdbcType) {
switch (jdbcType) {
case Types.BINARY:
case Types.VARBINARY:
case Types.LONGVARBINARY:
return true;
default:
return false;
}
}
/**
* Determine if an ASCII stream can be inserted into a column or parameter
* of type <code>jdbcType</code>.
*
* @param jdbcType JDBC type of column or parameter
* @return <code>true</code> if an ASCII stream can be inserted;
* <code>false</code> otherwise
*/
public static boolean isAsciiStreamAssignable(int jdbcType) {
return jdbcType == Types.CLOB || isCharacterType(jdbcType);
}
/**
* Determine if a binary stream can be inserted into a column or parameter
* of type <code>jdbcType</code>.
*
* @param jdbcType JDBC type of column or parameter
* @return <code>true</code> if a binary stream can be inserted;
* <code>false</code> otherwise
*/
public static boolean isBinaryStreamAssignable(int jdbcType) {
return jdbcType == Types.BLOB || isBinaryType(jdbcType);
}
/**
* Determine if a character stream can be inserted into a column or
* parameter of type <code>jdbcType</code>.
*
* @param jdbcType JDBC type of column or parameter
* @return <code>true</code> if a character stream can be inserted;
* <code>false</code> otherwise
*/
public static boolean isCharacterStreamAssignable(int jdbcType) {
// currently, we support the same types for ASCII streams and
// character streams
return isAsciiStreamAssignable(jdbcType);
}
public String toString()
{
return typeDescriptor.toString();
}
// Formatable methods
/**
* Read this object from a stream of stored objects.
*
* @param in read this.
*
* @exception IOException thrown on error
* @exception ClassNotFoundException thrown on error
*/
public void readExternal( ObjectInput in )
throws IOException, ClassNotFoundException
{
/* NOTE: We only write out the generic type id.
* typeId will be reset to be the generic type id
* when we get read back in since the generic
* one is all that is needed at execution time.
*/
typeId = (TypeId) in.readObject();
typeDescriptor = (TypeDescriptorImpl) in.readObject();
}
/**
* Write this object to a stream of stored objects.
*
* @param out write bytes here.
*
* @exception IOException thrown on error
*/
public void writeExternal( ObjectOutput out )
throws IOException
{
out.writeObject( typeId );
out.writeObject( typeDescriptor );
}
/**
* Get the formatID which corresponds to this class.
*
* @return the formatID of this class
*/
public int getTypeFormatId() { return StoredFormatIds.DATA_TYPE_SERVICES_IMPL_V01_ID; }
/**
* Check to make sure that this type id is something a user can create
* him/herself directly through an SQL CREATE TABLE statement.
*
* This method is used for CREATE TABLE AS ... WITH [NO] DATA binding
* because it's possible for the query to return types which are not
* actually creatable for a user. DERBY-2605.
*
* Three examples are:
*
* BOOLEAN: A user can select boolean columns from system tables, but
* s/he is not allowed to create such a column him/herself.
*
* JAVA_OBJECT: A user can select columns of various java object types
* from system tables, but s/he is not allowed to create such a column
* him/herself.
*
* DECIMAL: A user can specify a VALUES clause with a constant that
* has a precision of greater than 31. Derby can apparently handle
* such a value internally, but the user is not supposed to be able
* create such a column him/herself.
*
* @return True if the type associated with this DTD can be created via
* the CREATE TABLE syntax; false otherwise.
*/
public boolean isUserCreatableType() throws StandardException
{
switch (typeId.getJDBCTypeId())
{
case Types.BOOLEAN:
case Types.JAVA_OBJECT:
return false;
case Types.DECIMAL:
return
(getPrecision() <= typeId.getMaximumPrecision()) &&
(getScale() <= typeId.getMaximumScale()) &&
(getMaximumWidth() <= typeId.getMaximumMaximumWidth());
default: break;
}
return true;
}
/**
* Return the SQL type name and, if applicable, scale/precision/length
* for this DataTypeDescriptor. Note that we want the values from *this*
* object specifically, not the max values defined on this.typeId.
*/
public String getFullSQLTypeName()
{
StringBuffer sbuf = new StringBuffer(typeId.getSQLTypeName());
if (typeId.isDecimalTypeId() || typeId.isNumericTypeId())
{
sbuf.append("(");
sbuf.append(getPrecision());
sbuf.append(", ");
sbuf.append(getScale());
sbuf.append(")");
}
else if (typeId.variableLength())
{
sbuf.append("(");
sbuf.append(getMaximumWidth());
sbuf.append(")");
}
return sbuf.toString();
}
}