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

java.lang.Object
  extended by org.apache.derby.iapi.types.DataType
      extended by org.apache.derby.impl.store.access.conglomerate.GenericConglomerate
All Implemented Interfaces:
java.io.Externalizable, java.io.Serializable, java.lang.Comparable, Formatable, Storable, TypedFormat, Conglomerate, DataValueDescriptor, Orderable
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.DataValueDescriptor
UNKNOWN_LOGICAL_LENGTH
 
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
 DataValueDescriptor cloneValue(boolean forceMaterialization)
          Clone this DataValueDescriptor.
 int compare(DataValueDescriptor other)
          Compare this Orderable with a given Orderable for the purpose of index positioning.
 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 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, cloneHolder, coalesce, compare, compare, compare, compareTo, dataTypeConversion, equals, equals, flip, getBoolean, getByte, getBytes, getDate, getDouble, getFloat, getInt, getLong, getNationalString, getShort, getStream, getTime, getTimestamp, getTraceString, greaterOrEquals, greaterThan, hasStream, in, invalidFormat, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, notEquals, outOfRange, recycle, setBigDecimal, setInto, setInto, setObjectForCast, setToNull, setValue, 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.types.DataValueDescriptor
checkHostVariable, cloneHolder, coalesce, compare, compare, compare, equals, estimateMemoryUsage, getBoolean, getByte, getBytes, getDate, getDouble, getFloat, getInt, getLong, getShort, getStream, getTime, getTimestamp, getTraceString, greaterOrEquals, greaterThan, hasStream, in, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, notEquals, readExternalFromArray, recycle, setBigDecimal, setInto, setInto, setObjectForCast, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, typePrecedence, typeToBigDecimal
 
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
 

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()

cloneValue

public DataValueDescriptor cloneValue(boolean forceMaterialization)
Description copied from interface: DataValueDescriptor
Clone this DataValueDescriptor. Results in a new object that has the same value as this but can be modified independently.

Even though the objects can be modified independently regardless of the value of forceMaterialization, both the clone and the original may be dependent on the store state if forceMaterialization is set to false. An example is if you need to access the value you just read using cloneValue after the current transaction has ended, or after the source result set has been closed.

Specified by:
cloneValue in interface DataValueDescriptor
Parameters:
forceMaterialization - any streams representing the data value will be materialized if true, the data value will be kept as a stream if possible if false
Returns:
A clone of the DataValueDescriptor with the same initial value as this.
See Also:
DataValueDescriptor.cloneValue(boolean)

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)
Throws:
StandardException - Thrown on error
java.sql.SQLException - Error accessing the result set
See Also:
DataValueDescriptor.setValueFromResultSet(java.sql.ResultSet, int, boolean)

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
Throws:
StandardException
See Also:
DataValueDescriptor.setValue(int)

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)

Built on Thu 2012-03-29 21:53:33+0000, from revision ???

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