java.lang.Object
org.firebirdsql.gds.ng.fields.FieldDescriptor
The class
FieldDescriptor
contains the column metadata of the XSQLVAR server
data structure used to describe one column for input or output.
FieldDescriptor is an immutable type, the value of a field is maintained separately in RowValue
.
- Author:
- Mark Rotteveel
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Constructor Summary
ConstructorsConstructorDescriptionFieldDescriptor
(int position, DatatypeCoder datatypeCoder, int type, int subType, int scale, int length, String fieldName, String tableAlias, String originalName, String originalTableName, String ownerName) Constructor for metadata FieldDescriptor. -
Method Summary
Modifier and TypeMethodDescriptionboolean
int
The length in characters of this field.int
Determines the character set id (without collation id).int
byte
Padding to use for fields of this type.int
The position of the field in the row or parameter set.int
getScale()
int
int
getType()
int
hashCode()
boolean
isDbKey()
Determines if this is a db-key (RDB$DB_KEY) of a table.boolean
isFbType
(int fbType) Check if the type of this field is the specified Firebird data type.boolean
boolean
toString()
boolean
typeEquals
(FieldDescriptor other) Limited equals that only checks if the data type in the provided field descriptor is the same as this descriptor.
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Constructor Details
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FieldDescriptor
public FieldDescriptor(int position, DatatypeCoder datatypeCoder, int type, int subType, int scale, int length, String fieldName, String tableAlias, String originalName, String originalTableName, String ownerName) Constructor for metadata FieldDescriptor.- Parameters:
position
- Position of this field (0-based), or-1
if position is not known (e.g. for test code)datatypeCoder
- Instance of DatatypeCoder to use when decoding column data (note that another instance may be derived internally, which then will be returned bygetDatatypeCoder()
)type
- Column SQL typesubType
- Column subtypescale
- Column scalelength
- Column defined lengthfieldName
- Column alias nametableAlias
- Column table aliasoriginalName
- Column original nameoriginalTableName
- Column original tableownerName
- Owner of the column/table
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Method Details
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getPosition
public int getPosition()The position of the field in the row or parameter set.In general this should be equal to the position of this descriptor in
RowDescriptor
, but in some cases (usually test code), it might be-1
instead.- Returns:
- The 0-based position of this field in the row or parameter set (or
-1
if unknown)
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getDatatypeCoder
- Returns:
- The
DatatypeCoder
to use when decoding field data.
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getEncodingFactory
- Returns:
- The
IEncodingFactory
for the associated connection.
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getType
public int getType()- Returns:
- The Firebird type of this field
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getSubType
public int getSubType()- Returns:
- The Firebird subtype of this field
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getScale
public int getScale()- Returns:
- The scale of this field
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getLength
public int getLength()- Returns:
- The declared (maximum) length of this field
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getFieldName
- Returns:
- The (aliased) field name
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getTableAlias
- Returns:
- The (aliased) table name
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getOriginalName
- Returns:
- The original name of the field (e.g. the column name in the table)
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getOriginalTableName
- Returns:
- The original table name
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getOwnerName
- Returns:
- The owner
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isVarying
public boolean isVarying()- Returns:
true
if the type is variable length (ieISCConstants.SQL_VARYING
).
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isFbType
public boolean isFbType(int fbType) Check if the type of this field is the specified Firebird data type.This method assumes the not-nullable data type is passed, on checking the nullable bit of
getType()
is set to0
.- Parameters:
fbType
- One of theSQL_
data type identifier values- Returns:
true
if the type is the same as the type of this field
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isNullable
public boolean isNullable()- Returns:
true
if this field is nullable.
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isDbKey
public boolean isDbKey()Determines if this is a db-key (RDB$DB_KEY) of a table.NOTE: Technically it could also be a normal
CHAR CHARACTER SET OCTETS
column calledDB_KEY
.- Returns:
true
if the field is a RDB$DB_KEY- Since:
- 4.0
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getCharacterLength
public int getCharacterLength()The length in characters of this field.This takes into account the max bytes per character of the character set.
- Returns:
- Character length, or
-1
for non-character types (including blobs)
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getCharacterSetId
public int getCharacterSetId()Determines the character set id (without collation id).- Returns:
- Character set id for the type, if the type has no character set, than
ISCConstants.CS_dynamic
is returned
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typeEquals
Limited equals that only checks if the data type in the provided field descriptor is the same as this descriptor.The fields checked are:
- type
- subType
- scale
- length
- Parameters:
other
- Field descriptor to check- Returns:
true
whenother
is not null and has the same type definition as this instance,false
otherwise.
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getPaddingByte
public byte getPaddingByte()Padding to use for fields of this type.- Returns:
- padding byte (generally 0x00, or 0x20 for non-binary character data).
- Since:
- 5
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toString
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equals
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hashCode
public int hashCode()
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