Class JDBCRowId

java.lang.Object
org.hsqldb.jdbc.JDBCRowId
All Implemented Interfaces:
RowId
public final class JDBCRowId extends Object implements RowId
The representation (mapping) in the Java programming language of an SQL ROWID value. An SQL ROWID is a built-in type, a value of which can be thought of as an address for its identified row in a database table. Whether that address is logical or, in any respects, physical is determined by its originating data source.

Methods in the interfaces ResultSet, CallableStatement, and PreparedStatement, such as getRowId and setRowId allow a programmer to access a SQL ROWID value. The RowId interface provides a method for representing the value of the ROWID as a byte array or as a String.

The method getRowIdLifetime in the interface DatabaseMetaData, can be used to determine if a RowId object remains valid for the duration of the transaction in which the RowId was created, the duration of the session in which the RowId was created, or, effectively, for as long as its identified row is not deleted. In addition to specifying the duration of its valid lifetime outside its originating data source, getRowIdLifetime specifies the duration of a ROWID value's valid lifetime within its originating data source. In this, it differs from a large object, because there is no limit on the valid lifetime of a large object within its originating data source.

All methods on the RowId interface must be fully implemented if the JDBC driver supports the data type.

Since:
JDK 1.6, HSQLDB 2.0
Author:
Campbell Burnet (campbell-burnet@users dot sourceforge.net)
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    JDBCRowId(byte[] id)
    Constructs a new JDBCRowId instance wrapping the given octet sequence.
    JDBCRowId(String hex)
    Constructs a new JDBCRowId instance whose internal octet sequence is that represented by the given hexadecimal character sequence.
    JDBCRowId(RowId id)
    Constructs a new JDBCRowId instance whose internal octet sequence is a copy of the octet sequence of the given RowId object.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    equals(Object obj)
    Compares this RowId to the specified object.
    byte[]
    getBytes()
    Returns an array of bytes representing the value of the SQL ROWID designated by this java.sql.RowId object.
    int
    hashCode()
    Returns a hash code value of this RowId object.
    String
    toString()
    Returns a String representing the value of the SQL ROWID designated by this java.sql.RowId object.

    Methods inherited from class Object

    getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • JDBCRowId

      public JDBCRowId(byte[] id) throws SQLException
      Constructs a new JDBCRowId instance wrapping the given octet sequence.

      This constructor may be used internally to retrieve result set values as RowId objects, yet it also may need to be public to allow access from other packages. As such (in the interest of efficiency) this object maintains a reference to the given octet sequence rather than making a copy; special care should be taken by external clients never to use this constructor with a byte array object that may later be modified externally.

      Parameters:
      id - the octet sequence representing the Rowid value
      Throws:
      SQLException - if the argument is null

    • JDBCRowId

      public JDBCRowId(RowId id) throws SQLException
      Constructs a new JDBCRowId instance whose internal octet sequence is a copy of the octet sequence of the given RowId object.
      Parameters:
      id - the octet sequence representing the Rowid value
      Throws:
      SQLException - if the argument is null

    • JDBCRowId

      public JDBCRowId(String hex) throws SQLException
      Constructs a new JDBCRowId instance whose internal octet sequence is that represented by the given hexadecimal character sequence.
      Parameters:
      hex - the hexadecimal character sequence from which to derive the internal octet sequence
      Throws:
      SQLException - if the argument is null or is not a valid hexadecimal character sequence

  • Method Details

    • equals

      public boolean equals(Object obj)
      Compares this RowId to the specified object. The result is true if and only if the argument is not null and is a RowId object that represents the same ROWID as this object.

      It is important to consider both the origin and the valid lifetime of a RowId when comparing it to another RowId. If both are valid, and both are from the same table on the same data source, then if they are equal they identify the same row; if one or more is no longer guaranteed to be valid, or if they originate from different data sources, or different tables on the same data source, they may be equal but still not identify the same row.

      Specified by:
      equals in interface RowId
      Overrides:
      equals in class Object
      Parameters:
      obj - the Object to compare this RowId object against.
      Returns:
      true if the RowIds are equal; false otherwise
      Since:
      JDK 1.6, HSQLDB 2.0

    • getBytes

      public byte[] getBytes()
      Returns an array of bytes representing the value of the SQL ROWID designated by this java.sql.RowId object.
      Specified by:
      getBytes in interface RowId
      Returns:
      an array of bytes, whose length is determined by the driver supplying the connection, representing the value of the ROWID designated by this java.sql.RowId object.

    • toString

      public String toString()
      Returns a String representing the value of the SQL ROWID designated by this java.sql.RowId object.

      Like java.sql.Date.toString() returns the contents of its DATE as the String "2004-03-17" rather than as DATE literal in SQL (which would have been the String DATE "2004-03-17"), toString() returns the contents of its ROWID in a form specific to the driver supplying the connection, and possibly not as a ROWID literal.

      Specified by:
      toString in interface RowId
      Overrides:
      toString in class Object
      Returns:
      a String whose format is determined by the driver supplying the connection, representing the value of the ROWID designated by this java.sql.RowId object.

    • hashCode

      public int hashCode()
      Returns a hash code value of this RowId object.
      Specified by:
      hashCode in interface RowId
      Overrides:
      hashCode in class Object
      Returns:
      a hash code for the RowId