Package org.firebirdsql.gds.ng.fields

Class FieldDescriptor

java.lang.Object
org.firebirdsql.gds.ng.fields.FieldDescriptor
public final class FieldDescriptor extends Object
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.

Version:
3.0
Author:
Mark Rotteveel

  • Constructor Details

    • 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 (eg 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 by getDatatypeCoder())
      type - Column SQL type
      subType - Column subtype
      scale - Column scale
      length - Column defined length
      fieldName - Column alias name
      tableAlias - Column table alias
      originalName - Column original name
      originalTableName - Column original table
      ownerName - Owner of the column/table

  • Method Details

    • getPosition

      public int getPosition()
      Returns:
      The 0-based position of this field (or -1)

    • getDatatypeCoder

      public DatatypeCoder getDatatypeCoder()
      Returns:
      The DatatypeCoder to use when decoding field data.

    • getEncodingFactory

      public IEncodingFactory getEncodingFactory()
      Returns:
      The IEncodingFactory for the associated connection.

    • getType

      public int getType()
      Returns:
      The Firebird type of this field

    • getSubType

      public int getSubType()
      Returns:
      The Firebird subtype of this field

    • getScale

      public int getScale()
      Returns:
      The scale of this field

    • getLength

      public int getLength()
      Returns:
      The declared (maximum) length of this field

    • getFieldName

      public String getFieldName()
      Returns:
      The (aliased) field name

    • getTableAlias

      public String getTableAlias()
      Returns:
      The (aliased) table name

    • getOriginalName

      public String getOriginalName()
      Returns:
      The original name of the field (eg the column name in the table)

    • getOriginalTableName

      public String getOriginalTableName()
      Returns:
      The original table name

    • getOwnerName

      public String getOwnerName()
      Returns:
      The owner

    • isVarying

      public boolean isVarying()
      Returns:
      true if the type is variable length (ie ISCConstants.SQL_VARYING).

    • 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 to 0.

      Parameters:
      fbType - One of the SQL_ data type identifier values
      Returns:
      true if the type is the same as the type of this field

    • isNullable

      public boolean isNullable()
      Returns:
      true if this field is nullable.

    • 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 called DB_KEY.

      Returns:
      true if the field is a RDB$DB_KEY
      Since:
      4.0

    • 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)

    • typeEquals

      public boolean typeEquals(FieldDescriptor other)
      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 when other is not null and has the same type definition as this instance, false otherwise.

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object