org.apache.derby.impl.sql.compile
Class XMLTypeCompiler

java.lang.Object
  org.apache.derby.impl.sql.compile.BaseTypeCompiler
      org.apache.derby.impl.sql.compile.XMLTypeCompiler

All Implemented Interfaces:

TypeCompiler

public class XMLTypeCompiler

extends BaseTypeCompiler

This class implements TypeCompiler for the XML type.

Field Summary

Fields inherited from interface org.apache.derby.iapi.sql.compile.TypeCompiler

AVG_OP, BOOLEAN_MAXWIDTH_AS_CHAR, DEFAULT_DECIMAL_PRECISION, DEFAULT_DECIMAL_SCALE, DIVIDE_OP, DOUBLE_MAXWIDTH_AS_CHAR, INT_MAXWIDTH_AS_CHAR, LONGINT_MAXWIDTH_AS_CHAR, MAX_DECIMAL_PRECISION_SCALE, MINUS_OP, MOD_OP, PLUS_OP, REAL_MAXWIDTH_AS_CHAR, SMALLINT_MAXWIDTH_AS_CHAR, SUM_OP, TIMES_OP, TINYINT_MAXWIDTH_AS_CHAR

Constructor Summary

XMLTypeCompiler()

Method Summary

boolean	comparable(TypeId otherType, boolean forEquals, ClassFactory cs) Tell whether this type (XML) can be compared to the given type.
boolean	compatible(TypeId otherType) Tell whether this type (XML) is compatible with the given type.
boolean	convertible(TypeId otherType, boolean forDataTypeFunction) Tell whether this type (XML) can be converted to the given type.
protected java.lang.String	dataValueMethodName() Return the method name to get a Derby DataValueDescriptor object of the correct type.
void	generateDataValue(MethodBuilder mb, LocalField field) Generate the code necessary to produce a SQL value based on a value.
void	generateNull(MethodBuilder mb) Generate the code necessary to produce a SQL null of the appropriate type.
int	getCastToCharWidth(DataTypeDescriptor dts) Return the maximum width for this data type when cast to a char type.
java.lang.String	getCorrespondingPrimitiveTypeName() Get the name of the corresponding Java type.
java.lang.String	getMatchingNationalCharTypeName() Get the name of the matching national char type.
java.lang.String	getPrimitiveMethodName() Get the method name for getting out the corresponding primitive Java type.
protected int	getStoredFormatIdFromTypeId() Get the StoredFormatId from the corresponding TypeId.
protected TypeCompiler	getTypeCompiler(TypeId typeId) Get the TypeCompiler that corresponds to the given TypeId.
protected TypeId	getTypeId() Get the TypeId that corresponds to this TypeCompiler.
java.lang.String	interfaceName() Get the name of the interface for this type.
protected java.lang.String	nullMethodName()
boolean	numberComparable(TypeId otherType, boolean forEquals, ClassFactory cf) Tell whether this numeric type can be compared to the given type.
boolean	numberConvertible(TypeId otherType, boolean forDataTypeFunction) Tell whether this numeric type can be converted to the given type.
boolean	numberStorable(TypeId thisType, TypeId otherType, ClassFactory cf) Tell whether this numeric type can be stored into from the given type.
DataTypeDescriptor	resolveArithmeticOperation(DataTypeDescriptor leftType, DataTypeDescriptor rightType, java.lang.String operator) Type resolution methods on binary operators
(package private) void	setTypeId(TypeId typeId) Set the TypeCompiler that corresponds to the given TypeId.
boolean	storable(TypeId otherType, ClassFactory cf) Tell whether this type (XML) can be stored into from the given type.
protected boolean	userTypeStorable(TypeId thisType, TypeId otherType, ClassFactory cf) Determine whether thisType is storable in otherType due to otherType being a user type.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

XMLTypeCompiler

public XMLTypeCompiler()

Method Detail

comparable

public boolean comparable(TypeId otherType,
                          boolean forEquals,
                          ClassFactory cs)

Tell whether this type (XML) can be compared to the given type. Says SQL/XML[2003] spec: 4.2.2 XML comparison and assignment "XML values are not comparable."

Parameters:

otherType - The TypeId of the other type.

forEquals - True if this is an = or <> comparison, false otherwise.

cs - A ClassFactory

Returns:

true if the types can be compared, false if comparisons between the types are not allowed

convertible

public boolean convertible(TypeId otherType,
                           boolean forDataTypeFunction)

Tell whether this type (XML) can be converted to the given type. An XML value can't be converted to any other type, per SQL/XML[2003] 6.3

Parameters:

otherType - The CompilationType of the other type to compare this type to

forDataTypeFunction - true if this is a type function that requires more liberal behavior (e.g DOUBLE can convert a char but you cannot cast a CHAR to double.

Returns:

true if the types can be converted, false if conversion is not allowed

See Also:

TypeCompiler#convertible

compatible

public boolean compatible(TypeId otherType)

Tell whether this type (XML) is compatible with the given type.

Parameters:

otherType - The TypeId of the other type.

Returns:

true if the types are compatible, false if not compatible

storable

public boolean storable(TypeId otherType,
                        ClassFactory cf)

Tell whether this type (XML) can be stored into from the given type. Only XML values can be stored into an XML type, per SQL/XML spec: 4.2.2 XML comparison and assignment Values of XML type are assignable to sites of XML type.

Parameters:

otherType - The TypeId of the other type.

cf - A ClassFactory

Returns:

true if the other type can be stored in a column of this type.

interfaceName

public java.lang.String interfaceName()

Description copied from interface: TypeCompiler

Get the name of the interface for this type. For example, the interface for a SQLInteger is NumberDataValue. The full path name of the type is returned.

Returns:

The name of the interface for this type.

See Also:

TypeCompiler#interfaceName

getCorrespondingPrimitiveTypeName

public java.lang.String getCorrespondingPrimitiveTypeName()

Description copied from interface: TypeCompiler

Get the name of the corresponding Java type. For numerics and booleans we will get the corresponding Java primitive type. e Each SQL type has a corresponding Java type. When a SQL value is passed to a Java method, it is translated to its corresponding Java type. For example, a SQL Integer will be mapped to a Java int, but a SQL date will be mapped to a java.sql.Date.

Returns:

The name of the corresponding Java primitive type.

See Also:

TypeCompiler#getCorrespondingPrimitiveTypeName

getCastToCharWidth

public int getCastToCharWidth(DataTypeDescriptor dts)

Description copied from interface: TypeCompiler

Return the maximum width for this data type when cast to a char type.

Parameters:

dts - The associated DataTypeDescriptor for this TypeId.

Returns:

int The maximum width for this data type when cast to a char type.

See Also:

While it is true XML values can't be cast to char, this method can get called before we finish type checking--so we return a dummy value here and let the type check throw the appropriate error.

nullMethodName

protected java.lang.String nullMethodName()

Specified by:

nullMethodName in class BaseTypeCompiler

See Also:

TypeCompiler#nullMethodName

dataValueMethodName

protected java.lang.String dataValueMethodName()

Description copied from class: BaseTypeCompiler

Return the method name to get a Derby DataValueDescriptor object of the correct type. This implementation returns "getDataValue".

Overrides:

dataValueMethodName in class BaseTypeCompiler

See Also:

TypeCompiler#dataValueMethodName

getPrimitiveMethodName

public java.lang.String getPrimitiveMethodName()

Get the method name for getting out the corresponding primitive Java type.

Specified by:

getPrimitiveMethodName in interface TypeCompiler

Returns:

String The method call name for getting the corresponding primitive Java type.

getMatchingNationalCharTypeName

public java.lang.String getMatchingNationalCharTypeName()

Description copied from interface: TypeCompiler

Get the name of the matching national char type.

Specified by:

getMatchingNationalCharTypeName in interface TypeCompiler

Returns:

The name of the matching national char type.

See Also:

TypeCompiler.getMatchingNationalCharTypeName()

resolveArithmeticOperation

public DataTypeDescriptor resolveArithmeticOperation(DataTypeDescriptor leftType,
                                                     DataTypeDescriptor rightType,
                                                     java.lang.String operator)
                                              throws StandardException

Description copied from interface: TypeCompiler

Type resolution methods on binary operators

Specified by:

resolveArithmeticOperation in interface TypeCompiler

Parameters:

leftType - The type of the left parameter

rightType - The type of the right parameter

operator - The name of the operator (e.g. "+").

Returns:

The type of the result

Throws:

StandardException - Thrown on error

See Also:

TypeCompiler.resolveArithmeticOperation(org.apache.derby.iapi.types.DataTypeDescriptor, org.apache.derby.iapi.types.DataTypeDescriptor, java.lang.String)

generateNull

public void generateNull(MethodBuilder mb)

Description copied from interface: TypeCompiler

Generate the code necessary to produce a SQL null of the appropriate type. The stack must contain a DataValueFactory and a null or a value of the correct type (interfaceName()).

Specified by:

generateNull in interface TypeCompiler

Parameters:

mb - The method to put the expression in

See Also:

TypeCompiler.generateNull(org.apache.derby.iapi.services.compiler.MethodBuilder)

generateDataValue

public void generateDataValue(MethodBuilder mb,
                              LocalField field)

Description copied from interface: TypeCompiler

Generate the code necessary to produce a SQL value based on a value. The value's type is assumed to match the type of this TypeId. For example, a TypeId for the SQL int type should be given an value that evaluates to a Java int or Integer. If the type of the value is incorrect, the generated code will not work. The stack must contain data value factory value

Specified by:

generateDataValue in interface TypeCompiler

See Also:

TypeCompiler.generateDataValue(org.apache.derby.iapi.services.compiler.MethodBuilder, org.apache.derby.iapi.services.compiler.LocalField)

userTypeStorable

protected boolean userTypeStorable(TypeId thisType,
                                   TypeId otherType,
                                   ClassFactory cf)

Determine whether thisType is storable in otherType due to otherType being a user type.

Parameters:

thisType - The TypeId of the value to be stored

otherType - The TypeId of the value to be stored in

Returns:

true if thisType is storable in otherType

numberComparable

public boolean numberComparable(TypeId otherType,
                                boolean forEquals,
                                ClassFactory cf)

Tell whether this numeric type can be compared to the given type.

Parameters:

otherType - The TypeId of the other type.

numberConvertible

public boolean numberConvertible(TypeId otherType,
                                 boolean forDataTypeFunction)

Tell whether this numeric type can be converted to the given type.

Parameters:

otherType - The TypeId of the other type.

forDataTypeFunction - was this called from a scalarFunction like CHAR() or DOUBLE()

numberStorable

public boolean numberStorable(TypeId thisType,
                              TypeId otherType,
                              ClassFactory cf)

Tell whether this numeric type can be stored into from the given type.

Parameters:

thisType - The TypeId of this type

otherType - The TypeId of the other type.

cf - A ClassFactory

getTypeId

protected TypeId getTypeId()

Get the TypeId that corresponds to this TypeCompiler.

getTypeCompiler

protected TypeCompiler getTypeCompiler(TypeId typeId)

Get the TypeCompiler that corresponds to the given TypeId.

setTypeId

void setTypeId(TypeId typeId)

Set the TypeCompiler that corresponds to the given TypeId.

getStoredFormatIdFromTypeId

protected int getStoredFormatIdFromTypeId()

Get the StoredFormatId from the corresponding TypeId.

Returns:

The StoredFormatId from the corresponding TypeId.