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

java.lang.Object
  extended byorg.apache.derby.iapi.types.DataType
      extended byorg.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, getBigDecimal, getBoolean, getByte, getBytes, getDate, getDouble, getFloat, getInt, getLong, getNationalString, getShort, getStream, getTime, getTimestamp, greaterOrEquals, greaterThan, in, invalidFormat, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, notEquals, outOfRange, setInto, setInto, setObjectForCast, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, throwLangSetMismatch, typePrecedence
 
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, drop, fetchMaxOnBTree, getContainerid, getDynamicCompiledConglomInfo, getId, getStaticCompiledConglomInfo, isTemporary, load, open, openScan, openStoreCost
 
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, getBigDecimal, getBoolean, getByte, getBytes, getDate, getDouble, getFloat, getInt, getLong, getShort, getStream, getTime, getTimestamp, greaterOrEquals, greaterThan, in, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, notEquals, readExternalFromArray, setInto, setInto, setObjectForCast, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, typePrecedence
 

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)


Apache Derby V10.0 Engine Documentation - Copyright © 1997,2004 The Apache Software Foundation or its licensors, as applicable.