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

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

All Implemented Interfaces:

TypeCompiler

public class RefTypeCompiler
extends BaseTypeCompiler

This class implements TypeCompiler for the SQL REF datatype.

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

RefTypeCompiler()

Method Summary

boolean	compatible(TypeId otherType) Tell whether this type is compatible with the given type.
boolean	convertible(TypeId otherType, boolean forDataTypeFunction) Determine if this type can be CONVERTed to some other 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	interfaceName() Get the name of the interface for this type.
(package private) java.lang.String	nullMethodName() Return the method name to get a Derby DataValueDescriptor object of the correct type set to SQL NULL.
boolean	storable(TypeId otherType, ClassFactory cf) Determine if this type can have a value of another type stored into it.

Methods inherited from class org.apache.derby.impl.sql.compile.BaseTypeCompiler

dataValueMethodName, generateDataValue, generateNull, getPrimitiveMethodName, getStoredFormatIdFromTypeId, getTypeCompiler, getTypeId, numberConvertible, numberStorable, pushCollationForDataValue, resolveArithmeticOperation, setTypeId, userTypeStorable

Methods inherited from class java.lang.Object

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

Constructor Detail

RefTypeCompiler

public RefTypeCompiler()

Method Detail

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:

TypeCompiler.getCastToCharWidth(org.apache.derby.iapi.types.DataTypeDescriptor)

convertible

public boolean convertible(TypeId otherType,
                           boolean forDataTypeFunction)

Description copied from interface: TypeCompiler

Determine if this type can be CONVERTed to some other type

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(org.apache.derby.iapi.types.TypeId, boolean)

compatible

public boolean compatible(TypeId otherType)

Tell whether this type is compatible with the given type.

Parameters:

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

Returns:

true if the types are compatible, false if not compatible

See Also:

TypeCompiler.compatible(org.apache.derby.iapi.types.TypeId)

storable

public boolean storable(TypeId otherType,
                        ClassFactory cf)

Description copied from interface: TypeCompiler

Determine if this type can have a value of another type stored into it. Note that direction is relevant here: the test is that the otherType is storable into this type.

Parameters:

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

cf - A ClassFactory

Returns:

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

See Also:

TypeCompiler.storable(org.apache.derby.iapi.types.TypeId, org.apache.derby.iapi.services.loader.ClassFactory)

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()

nullMethodName

java.lang.String nullMethodName()

Description copied from class: BaseTypeCompiler

Return the method name to get a Derby DataValueDescriptor object of the correct type set to SQL NULL. The method named will be called with one argument: a holder object if pushCollationForDataValue() returns false, otherwise two arguments, the second being the collationType.

Specified by:

nullMethodName in class BaseTypeCompiler