Package org.h2.table

Class DualTable

  • All Implemented Interfaces:
    HasSQL

    public class DualTable
    extends VirtualTable
    The DUAL table for selects without a FROM clause.
    • Field Detail

      • NAME

        public static final java.lang.String NAME
        The name of the range table.
        See Also:
        Constant Field Values
    • Constructor Detail

      • DualTable

        public DualTable​(Database database)
        Create a new range with the given start and end expressions.
        Parameters:
        database - the database
    • Method Detail

      • getSQL

        public java.lang.StringBuilder getSQL​(java.lang.StringBuilder builder,
                                              int sqlFlags)
        Description copied from interface: HasSQL
        Appends the SQL statement of this object to the specified builder.
        Specified by:
        getSQL in interface HasSQL
        Overrides:
        getSQL in class SchemaObject
        Parameters:
        builder - string builder
        sqlFlags - formatting flags
        Returns:
        the specified string builder
      • canGetRowCount

        public boolean canGetRowCount​(SessionLocal session)
        Description copied from class: Table
        Check if the row count can be retrieved quickly.
        Specified by:
        canGetRowCount in class Table
        Parameters:
        session - the session
        Returns:
        true if it can
      • getRowCount

        public long getRowCount​(SessionLocal session)
        Description copied from class: Table
        Get the row count for this table.
        Specified by:
        getRowCount in class Table
        Parameters:
        session - the session
        Returns:
        the row count
      • getScanIndex

        public Index getScanIndex​(SessionLocal session)
        Description copied from class: Table
        Get the scan index to iterate through all rows.
        Specified by:
        getScanIndex in class Table
        Parameters:
        session - the session
        Returns:
        the index
      • getMaxDataModificationId

        public long getMaxDataModificationId()
        Description copied from class: Table
        Get the last data modification id.
        Specified by:
        getMaxDataModificationId in class Table
        Returns:
        the modification id
      • getRowCountApproximation

        public long getRowCountApproximation​(SessionLocal session)
        Description copied from class: Table
        Get the approximated row count for this table.
        Specified by:
        getRowCountApproximation in class Table
        Parameters:
        session - the session
        Returns:
        the approximated row count
      • isDeterministic

        public boolean isDeterministic()
        Description copied from class: Table
        Check if the table is deterministic.
        Specified by:
        isDeterministic in class Table
        Returns:
        true if it is