SQLRef (Apache Derby V10.10 Internals)

java.lang.Object
- org.apache.derby.iapi.types.DataType
- - org.apache.derby.iapi.types.SQLRef

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, java.lang.Comparable, Formatable, Storable, TypedFormat, DataValueDescriptor, Orderable, RefDataValue
```
public class SQLRef
extends DataType
implements RefDataValue
```
See Also:

Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

private static int BASE_MEMORY_USAGE

protected RowLocation value
- 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

Fields
Modifier and Type	Field and Description
`private static int`	`BASE_MEMORY_USAGE`
`protected RowLocation`	`value`

Constructor Summary

Constructors
Constructor and Description

SQLRef()

SQLRef(RowLocation rowLocation)

Constructors
Constructor and Description
`SQLRef()`
`SQLRef(RowLocation rowLocation)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`DataValueDescriptor`	`cloneValue(boolean forceMaterialization)` Clone this DataValueDescriptor.
`int`	`compare(DataValueDescriptor other)` Compare this Orderable with a given Orderable for the purpose of index positioning.
`boolean`	`compare(int op, DataValueDescriptor other, boolean orderedNulls, boolean unknownRV)` Compare this Orderable with a given Orderable for the purpose of qualification and sorting.
`int`	`estimateMemoryUsage()` Estimate the memory usage in bytes of the data value and the overhead of the class.
`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 int.
`java.lang.String`	`getString()` Gets the value in the data value descriptor as a String.
`int`	`getTypeFormatId()` Return my format identifier.
`java.lang.String`	`getTypeName()` Get the SQL name of the datatype
`boolean`	`isNull()` Return whether the value is null or not.
`void`	`readExternal(java.io.ObjectInput in)`
`void`	`restoreToNull()` Restore this object to its (SQL)null value.
`protected void`	`setFrom(DataValueDescriptor theValue)` Set the value of this DataValueDescriptor based on the value of the specified DataValueDescriptor.
`void`	`setInto(java.sql.PreparedStatement ps, int position)` Set this value into a PreparedStatement.
`void`	`setValue(RowLocation rowLocation)` Set the value of this RefDataValue.
`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.
`java.lang.String`	`toString()`
`void`	`writeExternal(java.io.ObjectOutput out)`

Methods inherited from class org.apache.derby.iapi.types.DataType
checkHostVariable, cloneHolder, coalesce, compare, compare, compareTo, dataTypeConversion, equals, equals, flip, genericSetObject, getBoolean, getByte, getBytes, getDate, getDouble, getFloat, getInt, getLong, getShort, getStream, getTime, getTimestamp, getTraceString, getTypeName, greaterOrEquals, greaterThan, hasStream, in, invalidFormat, isNotNull, isNullOp, lessOrEquals, lessThan, normalize, notEquals, outOfRange, readExternalFromArray, recycle, setBigDecimal, setInto, setObject, setObjectForCast, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, throwLangSetMismatch, throwLangSetMismatch, typePrecedence, typeToBigDecimal

Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.derby.iapi.types.DataValueDescriptor
checkHostVariable, cloneHolder, coalesce, compare, compare, equals, 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, setObjectForCast, setToNull, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, typePrecedence, typeToBigDecimal

- Field Detail
  - value
```
protected RowLocation value
```
  - BASE_MEMORY_USAGE
```
private static final int BASE_MEMORY_USAGE
```
- Constructor Detail
  - SQLRef
```
public SQLRef()
```
  - SQLRef
```
public SQLRef(RowLocation rowLocation)
```
- Method Detail
  - 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.
    
    Specified by:
    
    estimateMemoryUsage in interface DataValueDescriptor
    
    Returns:
    
    the estimated memory usage
  - getString
```
public java.lang.String getString()
```
    Description copied from interface: DataValueDescriptor
    
    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.
  - getObject
```
public java.lang.Object getObject()
```
    Description copied from class: DataType
    
    Gets the value in the data value descriptor as a int. Throws an exception if the data value is not receivable as a int.
    
    Specified by:
    
    getObject in interface DataValueDescriptor
    
    Overrides:
    
    getObject in class DataType
    
    Returns:
    
    The data value as a int.
  - setFrom
```
protected void setFrom(DataValueDescriptor theValue)
                throws StandardException
```
    Description copied from class: DataType
    
    Set the value of this DataValueDescriptor based on the value of the specified DataValueDescriptor.
    
    Overrides:
    
    setFrom in class DataType
    
    Parameters:
    
    theValue - The DataValueDescriptor that holds the value to which we want to set this DataValueDescriptor's value.
    
    Throws:
    
    StandardException
  - getLength
```
public int getLength()
```
    Description copied from interface: DataValueDescriptor
    
    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
  - getTypeName
```
public java.lang.String getTypeName()
```
    Description copied from interface: DataValueDescriptor
    
    Get the SQL name of the datatype
    
    Specified by:
    
    getTypeName in interface DataValueDescriptor
    
    Returns:
    
    The SQL name of the datatype
  - getTypeFormatId
```
public int getTypeFormatId()
```
    Return my format identifier.
    
    Specified by:
    
    getTypeFormatId in interface TypedFormat
    
    Returns:
    
    The identifier. (A UUID stuffed in an array of 16 bytes).
    
    See Also:
    
    TypedFormat.getTypeFormatId()
  - isNull
```
public boolean isNull()
```
    Description copied from interface: Storable
    
    Return whether the value is null or not.
    
    Specified by:
    
    isNull in interface Storable
    
    Returns:
    
    true if the value is null and false otherwise.
  - writeExternal
```
public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException
```
    Specified by:
    
    writeExternal in interface java.io.Externalizable
    
    Throws:
    
    java.io.IOException
  - readExternal
```
public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException
```
    Specified by:
    
    readExternal in interface java.io.Externalizable
    
    Throws:
    
    java.io.IOException - Thrown on error reading the object
    
    java.lang.ClassNotFoundException - Thrown if the class of the object read from the stream can't be found (not likely, since it's supposed to be SQLRef).
    
    See Also:
    
    Externalizable.readExternal(java.io.ObjectInput)
  - restoreToNull
```
public void restoreToNull()
```
    Description copied from interface: Storable
    
    Restore this object to its (SQL)null value.
    
    Specified by:
    
    restoreToNull in interface Storable
    
    See Also:
    
    Storable.restoreToNull()
  - compare
```
public boolean compare(int op,
                       DataValueDescriptor other,
                       boolean orderedNulls,
                       boolean unknownRV)
                throws StandardException
```
    Description copied from interface: DataValueDescriptor
    
    Compare this Orderable with a given Orderable for the purpose of qualification and sorting. The caller gets to determine how nulls should be treated - they can either be ordered values or unknown values.
    
    Specified by:
    
    compare in interface DataValueDescriptor
    
    Overrides:
    
    compare in class DataType
    
    Parameters:
    
    op - Orderable.ORDER_OP_EQUALS means do an = comparison. Orderable.ORDER_OP_LESSTHAN means compare this < other. Orderable.ORDER_OP_LESSOREQUALS means compare this <= other.
    
    other - The DataValueDescriptor to compare this one to.
    
    orderedNulls - True means to treat nulls as ordered values, that is, treat SQL null as equal to null, and less than all other values. False means to treat nulls as unknown values, that is, the result of any comparison with a null is the UNKNOWN truth value.
    
    unknownRV - The return value to use if the result of the comparison is the UNKNOWN truth value. In other words, if orderedNulls is false, and a null is involved in the comparison, return unknownRV. This parameter is not used orderedNulls is true.
    
    Returns:
    
    true if the comparison is true (duh!)
    
    Throws:
    
    StandardException - Thrown on error
  - compare
```
public int compare(DataValueDescriptor other)
            throws StandardException
```
    Description copied from interface: DataValueDescriptor
    
    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 greater 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
  - 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()
```
    Description copied from interface: DataValueDescriptor
    
    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)
```
    Description copied from interface: DataValueDescriptor
    
    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)
    
    See Also:
    
    DataValueDescriptor.setValueFromResultSet(java.sql.ResultSet, int, boolean)
  - setInto
```
public void setInto(java.sql.PreparedStatement ps,
                    int position)
```
    Description copied from interface: DataValueDescriptor
    
    Set this value into a PreparedStatement. This method must handle setting NULL into the PreparedStatement.
    
    Specified by:
    
    setInto in interface DataValueDescriptor
    
    Overrides:
    
    setInto in class DataType
  - setValue
```
public void setValue(RowLocation rowLocation)
```
    Description copied from interface: RefDataValue
    
    Set the value of this RefDataValue.
    
    Specified by:
    
    setValue in interface RefDataValue
    
    Parameters:
    
    rowLocation - Contains the boolean value to set this RefDataValue to. Null means set this RefDataValue to null.
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class SQLRef

Field Summary

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

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

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

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

Field Detail

value

BASE_MEMORY_USAGE

Constructor Detail

SQLRef

SQLRef

Method Detail

estimateMemoryUsage

getString

getObject

setFrom

getLength

getTypeName

getTypeFormatId

isNull

writeExternal

readExternal

restoreToNull

compare

compare

cloneValue

getNewNull

setValueFromResultSet

setInto

setValue

toString