org.apache.derby.impl.store.access.conglomerate
Class GenericConglomerate

java.lang.Object
  org.apache.derby.iapi.types.DataType
      org.apache.derby.impl.store.access.conglomerate.GenericConglomerate

All Implemented Interfaces:

CloneableObject, Conglomerate, DataValueDescriptor, java.io.Externalizable, Formatable, Orderable, java.io.Serializable, Storable, TypedFormat

Direct Known Subclasses:

BTree, Heap

public abstract class GenericConglomerate

extends DataType

implements Conglomerate

A class that implements the methods shared across all implementations of the Conglomerate interface.

See Also:

Serialized Form

Field Summary

Fields inherited from interface org.apache.derby.iapi.types.Orderable

ORDER_OP_EQUALS, ORDER_OP_GREATEROREQUALS, ORDER_OP_GREATERTHAN, ORDER_OP_LESSOREQUALS, ORDER_OP_LESSTHAN

Constructor Summary

GenericConglomerate()

Method Summary

int	compare(DataValueDescriptor other) Compare this Orderable with a given Orderable for the purpose of index positioning.
DataValueDescriptor	getClone() Shallow copy.
int	getLength() Gets the length of the data value.
DataValueDescriptor	getNewNull() Get a new null value of the same type as this data value.
java.lang.Object	getObject() Gets the value in the data value descriptor as a Java Object.
java.lang.String	getString() Gets the value in the data value descriptor as a String.
java.lang.String	getTypeName() Get the SQL name of the datatype
protected void	setFrom(DataValueDescriptor theValue) Set the value of this DataValueDescriptor from another.
void	setValue(java.lang.Object theValue) Set the value of this DataValueDescriptor to the given value
void	setValueFromResultSet(java.sql.ResultSet resultSet, int colNumber, boolean isNullable) Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.

Methods inherited from class org.apache.derby.iapi.types.DataType

checkHostVariable, cloneObject, coalesce, compare, dataTypeConversion, equals, equals, flip, genericSetObject, getBoolean, getByte, getBytes, getDate, getDouble, getFloat, getInt, getLong, getNationalString, getShort, getStream, getTime, getTimestamp, greaterOrEquals, greaterThan, in, invalidFormat, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, notEquals, outOfRange, setBigDecimal, setInto, setInto, setObjectForCast, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, throwLangSetMismatch, typePrecedence, typeToBigDecimal

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.derby.iapi.store.access.conglomerate.Conglomerate

addColumn, compressConglomerate, defragmentConglomerate, drop, fetchMaxOnBTree, getContainerid, getDynamicCompiledConglomInfo, getId, getStaticCompiledConglomInfo, isTemporary, load, open, openScan, openStoreCost, purgeConglomerate

Methods inherited from interface org.apache.derby.iapi.services.io.Storable

isNull, restoreToNull

Methods inherited from interface java.io.Externalizable

readExternal, writeExternal

Methods inherited from interface org.apache.derby.iapi.services.io.TypedFormat

getTypeFormatId

Methods inherited from interface org.apache.derby.iapi.types.DataValueDescriptor

checkHostVariable, coalesce, compare, equals, estimateMemoryUsage, getBoolean, getByte, getBytes, getDate, getDouble, getFloat, getInt, getLong, getShort, getStream, getTime, getTimestamp, greaterOrEquals, greaterThan, in, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, notEquals, readExternalFromArray, setBigDecimal, setInto, setInto, setObjectForCast, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, typePrecedence, typeToBigDecimal

Constructor Detail

GenericConglomerate

public GenericConglomerate()

Method Detail

getLength

public int getLength()
              throws StandardException

Gets the length of the data value. The meaning of this is implementation-dependent. For string types, it is the number of characters in the string. For numeric types, it is the number of bytes used to store the number. This is the actual length of this value, not the length of the type it was defined as. For example, a VARCHAR value may be shorter than the declared VARCHAR (maximum) length.

Specified by:

getLength in interface DataValueDescriptor

Returns:

The length of the data value

Throws:

StandardException - On error

See Also:

DataValueDescriptor.getLength()

getString

public java.lang.String getString()
                           throws StandardException

Gets the value in the data value descriptor as a String. Throws an exception if the data value is not a string.

Specified by:

getString in interface DataValueDescriptor

Returns:

The data value as a String.

Throws:

StandardException - Thrown on error

See Also:

DataValueDescriptor.getString()

getObject

public java.lang.Object getObject()
                           throws StandardException

Gets the value in the data value descriptor as a Java Object. The type of the Object will be the Java object type corresponding to the data value's SQL type. JDBC defines a mapping between Java object types and SQL types - we will allow that to be extended through user type definitions. Throws an exception if the data value is not an object (yeah, right).

Specified by:

getObject in interface DataValueDescriptor

Overrides:

getObject in class DataType

Returns:

The data value as an Object.

Throws:

StandardException - Thrown on error

See Also:

DataValueDescriptor.getObject()

getClone

public DataValueDescriptor getClone()

Shallow copy.

Clone the DataValueDescriptor and copy its contents. We clone the data value wrapper (e.g. SQLDecimal) and reuse its contents (the underlying BigDecimal). The resultant DataValueDescriptor will point to the same value as the original DataValueDescriptor (unless the value is a primitive type, e.g. SQLInteger/integer).

Specified by:

getClone in interface DataValueDescriptor

Returns:

A clone of the DataValueDescriptor reusing its contents.

See Also:

DataValueDescriptor.getClone()

getNewNull

public DataValueDescriptor getNewNull()

Get a new null value of the same type as this data value.

Specified by:

getNewNull in interface DataValueDescriptor

See Also:

DataValueDescriptor.getNewNull()

setValueFromResultSet

public void setValueFromResultSet(java.sql.ResultSet resultSet,
                                  int colNumber,
                                  boolean isNullable)
                           throws StandardException,
                                  java.sql.SQLException

Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.

Specified by:

setValueFromResultSet in interface DataValueDescriptor

Parameters:

resultSet - The specified ResultSet.

colNumber - The 1-based column # into the resultSet.

isNullable - Whether or not the column is nullable (No need to call wasNull() if not)

Returns:

Nothing.

Throws:

StandardException - Thrown on error

java.sql.SQLException - Error accessing the result set

See Also:

DataValueDescriptor.setValueFromResultSet(java.sql.ResultSet, int, boolean)

setValue

public void setValue(java.lang.Object theValue)
              throws StandardException

Set the value of this DataValueDescriptor to the given value

Specified by:

setValue in interface DataValueDescriptor

Overrides:

setValue in class DataType

Parameters:

theValue - An Object containing the value to set this DataValueDescriptor to. Null means set the value to SQL null.

Returns:

This DataValueDescriptor

Throws:

StandardException - Thrown on error

See Also:

DataValueDescriptor.setValue(java.lang.Object)

setFrom

protected void setFrom(DataValueDescriptor theValue)
                throws StandardException

Set the value of this DataValueDescriptor from another.

Overrides:

setFrom in class DataType

Parameters:

theValue - The Date value to set this DataValueDescriptor to

Returns:

This DataValueDescriptor

Throws:

StandardException

See Also:

DataValueDescriptor.setValue(java.lang.Object)

getTypeName

public java.lang.String getTypeName()

Get the SQL name of the datatype

Specified by:

getTypeName in interface DataValueDescriptor

Returns:

The SQL name of the datatype

See Also:

DataValueDescriptor.getTypeName()

compare

public int compare(DataValueDescriptor other)
            throws StandardException

Compare this Orderable with a given Orderable for the purpose of index positioning. This method treats nulls as ordered values - that is, it treats SQL null as equal to null and less than all other values.

Specified by:

compare in interface DataValueDescriptor

Parameters:

other - The Orderable to compare this one to.

Returns:

<0 - this Orderable is less than other. 0 - this Orderable equals other. >0 - this Orderable is greater than other. The code should not explicitly look for -1, or 1.

Throws:

StandardException - Thrown on error

See Also:

DataValueDescriptor.compare(org.apache.derby.iapi.types.DataValueDescriptor)