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org.apache.derby.iapi.types
Class DataTypeDescriptor  

java.lang.Object
  org.apache.derby.iapi.types.DataTypeDescriptor

All Implemented Interfaces:

java.io.Externalizable, org.apache.derby.iapi.services.io.Formatable, java.io.Serializable, org.apache.derby.catalog.TypeDescriptor, org.apache.derby.iapi.services.io.TypedFormat

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public final class DataTypeDescriptor

extends java.lang.Object

implements org.apache.derby.catalog.TypeDescriptor, org.apache.derby.iapi.services.io.Formatable

This is an implementation of DataTypeDescriptor from the generic language datatype module interface.

Version:

1.0

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Field Summary
private  org.apache.derby.catalog.types.TypeDescriptorImpl	typeDescriptor
private  TypeId	typeId

 

Fields inherited from interface org.apache.derby.catalog.TypeDescriptor

MAXIMUM_WIDTH_UNKNOWN

 

Constructor Summary

DataTypeDescriptor()           Public niladic constructor.

DataTypeDescriptor(DataTypeDescriptor source, boolean isNullable)

DataTypeDescriptor(DataTypeDescriptor source, boolean isNullable, int maximumWidth)           Constructor for internal uses only

DataTypeDescriptor(DataTypeDescriptor source, int precision, int scale, boolean isNullable, int maximumWidth)           Constructor for internal uses only.

DataTypeDescriptor(org.apache.derby.catalog.types.TypeDescriptorImpl source, TypeId typeId)           Constructor for use in reconstructing a DataTypeDescriptor from a TypeDescriptorImpl and a TypeId

DataTypeDescriptor(TypeId typeId, boolean isNullable)

DataTypeDescriptor(TypeId typeId, boolean isNullable, int maximumWidth)           Constructor for use with non-numeric types

DataTypeDescriptor(TypeId typeId, int precision, int scale, boolean isNullable, int maximumWidth)           Constructor for use with numeric types

 

Method Summary
boolean	equals(java.lang.Object aTypeDescriptor)           Compare if two TypeDescriptors are exactly the same
double	estimatedMemoryUsage()           Get the estimated memory usage for this type descriptor.
static DataTypeDescriptor	getBuiltInDataTypeDescriptor(int jdbcType)           Get a descriptor that corresponds to a builtin JDBC type.
static DataTypeDescriptor	getBuiltInDataTypeDescriptor(int jdbcType, boolean isNullable)           Get a descriptor that corresponds to a builtin JDBC type.
static DataTypeDescriptor	getBuiltInDataTypeDescriptor(int jdbcType, boolean isNullable, int maxLength)           Get a descriptor that corresponds to a builtin JDBC type.
static DataTypeDescriptor	getBuiltInDataTypeDescriptor(int jdbcType, int length)
static DataTypeDescriptor	getBuiltInDataTypeDescriptor(java.lang.String sqlTypeName)           Get a DataTypeServices that corresponds to a builtin SQL type
static DataTypeDescriptor	getBuiltInDataTypeDescriptor(java.lang.String sqlTypeName, int length)           Get a DataTypeServices that corresponds to a builtin SQL type
org.apache.derby.catalog.types.TypeDescriptorImpl	getCatalogType()           Get the simplified type descriptor that is intended to be stored in the system tables.
DataTypeDescriptor	getDominantType(DataTypeDescriptor otherDTS, org.apache.derby.iapi.services.loader.ClassFactory cf)           Get the dominant type (DataTypeDescriptor) of the 2.
int	getJDBCTypeId()           Get the jdbc type id for this type.
int	getMaximumWidth()           Returns the maximum width of the type.
int	getMaximumWidthInBytes()           Returns the maximum width of the type IN BYTES.
DataValueDescriptor	getNull()           Get a Null for this type.
int	getPrecision()           Returns the number of decimal digits for the datatype, if applicable.
int	getScale()           Returns the number of digits to the right of the decimal for the datatype, if applicable.
static DataTypeDescriptor	getSQLDataTypeDescriptor(java.lang.String javaTypeName)           Get a DataTypeServices that corresponds to a Java type
static DataTypeDescriptor	getSQLDataTypeDescriptor(java.lang.String javaTypeName, boolean isNullable)           Get a DataTypeServices that corresponds to a Java type
static DataTypeDescriptor	getSQLDataTypeDescriptor(java.lang.String javaTypeName, int precision, int scale, boolean isNullable, int maximumWidth)           Get a DataTypeDescriptor that corresponds to a Java type
java.lang.String	getSQLstring()           Converts this data type descriptor (including length/precision) to a string.
int	getTypeFormatId()           Get the formatID which corresponds to this class.
TypeId	getTypeId()           Gets the TypeId for the datatype.
java.lang.String	getTypeName()           Gets the name of this datatype.
private static boolean	isBinaryType(int jdbcType)
private static boolean	isCharacterType(int jdbcType)
boolean	isExactTypeAndLengthMatch(DataTypeDescriptor otherDTS)           Check whether or not the 2 types (DataTypeDescriptor) have the same type and length.
static boolean	isJDBCTypeEquivalent(int existingType, int jdbcTypeId)           Compare JdbcTypeIds to determine if they represent equivalent SQL types.
boolean	isNullable()           Returns TRUE if the datatype can contain NULL, FALSE if not.
static boolean	isNumericType(int jdbcType)
DataValueDescriptor	normalize(DataValueDescriptor source, DataValueDescriptor cachedDest)
void	readExternal(java.io.ObjectInput in)           Read this object from a stream of stored objects.
void	setNullability(boolean nullable)           Set the nullability of the datatype described by this descriptor
java.lang.String	toString()           Convert this Object to a human-readable String.
void	writeExternal(java.io.ObjectOutput out)           Write this object to a stream of stored objects.

 

Methods inherited from class java.lang.Object

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

 

Field Detail

typeDescriptor

private org.apache.derby.catalog.types.TypeDescriptorImpl typeDescriptor

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typeId

private TypeId typeId

Constructor Detail

DataTypeDescriptor

public DataTypeDescriptor()

Public niladic constructor. Needed for Formatable interface to work.

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DataTypeDescriptor

public DataTypeDescriptor(TypeId typeId,
                          int precision,
                          int scale,
                          boolean isNullable,
                          int maximumWidth)

Constructor for use with numeric types

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DataTypeDescriptor

public DataTypeDescriptor(TypeId typeId,
                          boolean isNullable,
                          int maximumWidth)

Constructor for use with non-numeric types

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DataTypeDescriptor

public DataTypeDescriptor(TypeId typeId,
                          boolean isNullable)

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DataTypeDescriptor

public DataTypeDescriptor(DataTypeDescriptor source,
                          boolean isNullable)

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DataTypeDescriptor

public DataTypeDescriptor(DataTypeDescriptor source,
                          int precision,
                          int scale,
                          boolean isNullable,
                          int maximumWidth)

Constructor for internal uses only. (This is useful when the precision and scale are potentially wider than those in the source, like when determining the dominant data type.)

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DataTypeDescriptor

public DataTypeDescriptor(DataTypeDescriptor source,
                          boolean isNullable,
                          int maximumWidth)

Constructor for internal uses only

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DataTypeDescriptor

public DataTypeDescriptor(org.apache.derby.catalog.types.TypeDescriptorImpl source,
                          TypeId typeId)

Constructor for use in reconstructing a DataTypeDescriptor from a TypeDescriptorImpl and a TypeId

Method Detail

getBuiltInDataTypeDescriptor

public static DataTypeDescriptor getBuiltInDataTypeDescriptor(int jdbcType)

Get a descriptor that corresponds to a builtin JDBC type.

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getBuiltInDataTypeDescriptor

public static DataTypeDescriptor getBuiltInDataTypeDescriptor(int jdbcType,
                                                              int length)

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getBuiltInDataTypeDescriptor

public static DataTypeDescriptor getBuiltInDataTypeDescriptor(int jdbcType,
                                                              boolean isNullable)

Get a descriptor that corresponds to a builtin JDBC type.

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getBuiltInDataTypeDescriptor

public static DataTypeDescriptor getBuiltInDataTypeDescriptor(int jdbcType,
                                                              boolean isNullable,
                                                              int maxLength)

Get a descriptor that corresponds to a builtin JDBC type.

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getBuiltInDataTypeDescriptor

public static DataTypeDescriptor getBuiltInDataTypeDescriptor(java.lang.String sqlTypeName)

Get a DataTypeServices that corresponds to a builtin SQL type

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getBuiltInDataTypeDescriptor

public static DataTypeDescriptor getBuiltInDataTypeDescriptor(java.lang.String sqlTypeName,
                                                              int length)

Get a DataTypeServices that corresponds to a builtin SQL type

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getSQLDataTypeDescriptor

public static DataTypeDescriptor getSQLDataTypeDescriptor(java.lang.String javaTypeName)

Get a DataTypeServices that corresponds to a Java type

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getSQLDataTypeDescriptor

public static DataTypeDescriptor getSQLDataTypeDescriptor(java.lang.String javaTypeName,
                                                          boolean isNullable)

Get a DataTypeServices that corresponds to a Java type

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getSQLDataTypeDescriptor

public static DataTypeDescriptor getSQLDataTypeDescriptor(java.lang.String javaTypeName,
                                                          int precision,
                                                          int scale,
                                                          boolean isNullable,
                                                          int maximumWidth)

Get a DataTypeDescriptor that corresponds to a Java type

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normalize

public DataValueDescriptor normalize(DataValueDescriptor source,
                                     DataValueDescriptor cachedDest)
                              throws org.apache.derby.iapi.error.StandardException

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getDominantType

public DataTypeDescriptor getDominantType(DataTypeDescriptor otherDTS,
                                          org.apache.derby.iapi.services.loader.ClassFactory cf)
                                   throws org.apache.derby.iapi.error.StandardException

Get the dominant type (DataTypeDescriptor) of the 2. For variable length types, the resulting type will have the biggest max length of the 2. If either side is nullable, then the result will also be nullable.

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isExactTypeAndLengthMatch

public boolean isExactTypeAndLengthMatch(DataTypeDescriptor otherDTS)

Check whether or not the 2 types (DataTypeDescriptor) have the same type and length. This is useful for UNION when trying to decide whether a NormalizeResultSet is required.

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getMaximumWidth

public int getMaximumWidth()

Description copied from interface: org.apache.derby.catalog.TypeDescriptor

Returns the maximum width of the type. This may have different meanings for different types. For example, with char, it means the maximum number of characters, while with int, it is the number of bytes (i.e. 4).

Specified by:

getMaximumWidth in interface org.apache.derby.catalog.TypeDescriptor

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getMaximumWidthInBytes

public int getMaximumWidthInBytes()

Description copied from interface: org.apache.derby.catalog.TypeDescriptor

Returns the maximum width of the type IN BYTES. This is the maximum number of bytes that could be returned for this type if the corresponding getXXX() method is used. For example, if we have a CHAR type, then we want the number of bytes that would be returned by a ResultSet.getString() call.

Specified by:

getMaximumWidthInBytes in interface org.apache.derby.catalog.TypeDescriptor

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getTypeId

public TypeId getTypeId()

Gets the TypeId for the datatype.

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getNull

public DataValueDescriptor getNull()

Get a Null for this type.

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getTypeName

public java.lang.String getTypeName()

Gets the name of this datatype.

Specified by:

getTypeName in interface org.apache.derby.catalog.TypeDescriptor

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getJDBCTypeId

public int getJDBCTypeId()

Get the jdbc type id for this type. JDBC type can be found in java.sql.Types.

Specified by:

getJDBCTypeId in interface org.apache.derby.catalog.TypeDescriptor

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getPrecision

public int getPrecision()

Returns the number of decimal digits for the datatype, if applicable.

Specified by:

getPrecision in interface org.apache.derby.catalog.TypeDescriptor

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getScale

public int getScale()

Returns the number of digits to the right of the decimal for the datatype, if applicable.

Specified by:

getScale in interface org.apache.derby.catalog.TypeDescriptor

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isNullable

public boolean isNullable()

Returns TRUE if the datatype can contain NULL, FALSE if not. JDBC supports a return value meaning "nullability unknown" - I assume we will never have columns where the nullability is unknown.

Specified by:

isNullable in interface org.apache.derby.catalog.TypeDescriptor

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setNullability

public void setNullability(boolean nullable)

Set the nullability of the datatype described by this descriptor

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equals

public boolean equals(java.lang.Object aTypeDescriptor)

Compare if two TypeDescriptors are exactly the same

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getSQLstring

public java.lang.String getSQLstring()

Converts this data type descriptor (including length/precision) to a string. E.g. VARCHAR(30) or java.util.Hashtable

Specified by:

getSQLstring in interface org.apache.derby.catalog.TypeDescriptor

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getCatalogType

public org.apache.derby.catalog.types.TypeDescriptorImpl getCatalogType()

Get the simplified type descriptor that is intended to be stored in the system tables.

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estimatedMemoryUsage

public double estimatedMemoryUsage()

Get the estimated memory usage for this type descriptor.

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isJDBCTypeEquivalent

public static boolean isJDBCTypeEquivalent(int existingType,
                                           int jdbcTypeId)

Compare JdbcTypeIds to determine if they represent equivalent SQL types. For example Types.NUMERIC and Types.DECIMAL are equivalent

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isNumericType

public static boolean isNumericType(int jdbcType)

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isCharacterType

private static boolean isCharacterType(int jdbcType)

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isBinaryType

private static boolean isBinaryType(int jdbcType)

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toString

public java.lang.String toString()

Description copied from class: java.lang.Object

Convert this Object to a human-readable String. There are no limits placed on how long this String should be or what it should contain. We suggest you make it as intuitive as possible to be able to place it into System.out.println() 55 and such.

It is typical, but not required, to ensure that this method never completes abruptly with a java.lang.RuntimeException.

This method will be called when performing string concatenation with this object. If the result is null, string concatenation will instead use "null".

The default implementation returns getClass().getName() + "@" + Integer.toHexString(hashCode()).

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readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Read this object from a stream of stored objects.

Specified by:

readExternal in interface java.io.Externalizable

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writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Write this object to a stream of stored objects.

Specified by:

writeExternal in interface java.io.Externalizable

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getTypeFormatId

public int getTypeFormatId()

Get the formatID which corresponds to this class.

Specified by:

getTypeFormatId in interface org.apache.derby.iapi.services.io.TypedFormat

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Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> iapi >> [ types overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

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