Class StorableFormatId
java.lang.Object
org.apache.derby.iapi.types.DataType
org.apache.derby.impl.store.access.StorableFormatId
- All Implemented Interfaces:
Externalizable
,Serializable
,Comparable
,Formatable
,Storable
,TypedFormat
,DataValueDescriptor
,Orderable
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final int
private int
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
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptioncloneValue
(boolean forceMaterialization) Clone this DataValueDescriptor.int
compare
(DataValueDescriptor other) Compare this Orderable with a given Orderable for the purpose of index positioning.int
Estimate the memory usage in bytes of the data value and the overhead of the class.int
Gets the length of the data value.Get a new null value of the same type as this data value.Gets the value in the data value descriptor as a Java Object.Gets the value in the data value descriptor as a String.int
Return my format identifier.Get the SQL name of the datatypeint
getValue()
boolean
isNull()
Return whether the value is null or not.void
void
Restore this object to its (SQL)null value.protected void
setFrom
(DataValueDescriptor theValue) Set the value of this DataValueDescriptor from another.void
setValue
(int input_value) Set the value of this DataValueDescriptor to the given int value At DataType level just throws an error lower classes will overridevoid
setValueFromResultSet
(ResultSet resultSet, int colNumber, boolean isNullable) Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.void
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, getShort, getStream, getTime, getTimestamp, getTraceString, greaterOrEquals, greaterThan, hasStream, in, invalidFormat, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, notEquals, outOfRange, 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, setValue, throwLangSetMismatch, typePrecedence, typeToBigDecimal
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Field Details
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format_id
private int format_id -
BASE_MEMORY_USAGE
private static final int BASE_MEMORY_USAGE
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Constructor Details
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StorableFormatId
public StorableFormatId() -
StorableFormatId
public StorableFormatId(int value)
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Method Details
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estimateMemoryUsage
public int estimateMemoryUsage()Description copied from interface:DataValueDescriptor
Estimate the memory usage in bytes of the data value and the overhead of the class.- Returns:
- the estimated memory usage
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getValue
public int getValue() -
setValue
public void setValue(int input_value) Description copied from class:DataType
Set the value of this DataValueDescriptor to the given int value At DataType level just throws an error lower classes will override- Specified by:
setValue
in interfaceDataValueDescriptor
- Overrides:
setValue
in classDataType
- Parameters:
input_value
- The value to set this DataValueDescriptor to
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getTypeFormatId
public int getTypeFormatId()Return my format identifier.- Returns:
- The identifier. (A UUID stuffed in an array of 16 bytes).
- See Also:
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isNull
public boolean isNull()Description copied from interface:Storable
Return whether the value is null or not.- Returns:
- true if the value is null and false otherwise.
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writeExternal
- Throws:
IOException
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readExternal
- Throws:
IOException
- See Also:
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restoreToNull
public void restoreToNull()Description copied from interface:Storable
Restore this object to its (SQL)null value. -
getLength
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.- Returns:
- The length of the data value
- Throws:
StandardException
- On error- See Also:
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getString
Gets the value in the data value descriptor as a String. Throws an exception if the data value is not a string.- Returns:
- The data value as a String.
- Throws:
StandardException
- Thrown on error- See Also:
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getObject
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 interfaceDataValueDescriptor
- Overrides:
getObject
in classDataType
- Returns:
- The data value as an Object.
- Throws:
StandardException
- Thrown on error- See Also:
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cloneValue
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 ifforceMaterialization
is set tofalse
. An example is if you need to access the value you just read usingcloneValue
after the current transaction has ended, or after the source result set has been closed.- Parameters:
forceMaterialization
- any streams representing the data value will be materialized iftrue
, the data value will be kept as a stream if possible iffalse
- Returns:
- A clone of the
DataValueDescriptor
with the same initial value as this. - See Also:
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getNewNull
Get a new null value of the same type as this data value.- See Also:
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setValueFromResultSet
public void setValueFromResultSet(ResultSet resultSet, int colNumber, boolean isNullable) throws StandardException, SQLException Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.- 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 errorSQLException
- Error accessing the result set- See Also:
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setFrom
Set the value of this DataValueDescriptor from another.- Overrides:
setFrom
in classDataType
- Parameters:
theValue
- The Date value to set this DataValueDescriptor to- Throws:
StandardException
- See Also:
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getTypeName
Get the SQL name of the datatype- Returns:
- The SQL name of the datatype
- See Also:
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compare
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.- 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:
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