Class ColumnDescriptor


  • public final class ColumnDescriptor
    extends TupleDescriptor
    This class represents a column descriptor. public methods in this class are:
    1. long getAutoincStart()
    2. java.lang.String getColumnName()
    3. DefaultDescriptor getDefaultDescriptor(DataDictionary dd)
    4. DefaultInfo getDefaultInfo
    5. UUID getDefaultUUID
    6. DataValueDescriptor getDefaultValue
    7. int getPosition()
    8. UUID getReferencingUUID()
    9. TableDescriptor getTableDescriptor
    10. DTD getType()
    11. hasNonNullDefault
    12. isAutoincrement
    13. setColumnName
    14. setPosition
    • Field Detail

      • columnDefaultInfo

        private DefaultInfo columnDefaultInfo
      • columnName

        private java.lang.String columnName
      • columnPosition

        private int columnPosition
      • uuid

        private UUID uuid
      • defaultUUID

        private UUID defaultUUID
      • autoincStart

        private long autoincStart
      • autoincInc

        private long autoincInc
      • autoincValue

        private long autoincValue
      • autoincCycle

        private boolean autoincCycle
      • autoinc_create_or_modify_Start_Increment

        long autoinc_create_or_modify_Start_Increment
    • Constructor Detail

      • ColumnDescriptor

        public ColumnDescriptor​(java.lang.String columnName,
                                int columnPosition,
                                DataTypeDescriptor columnType,
                                DataValueDescriptor columnDefault,
                                DefaultInfo columnDefaultInfo,
                                TableDescriptor table,
                                UUID defaultUUID,
                                long autoincStart,
                                long autoincInc,
                                long userChangedWhat,
                                boolean autoincCycle)
        Constructor for a ColumnDescriptor when the column involved is an autoincrement column. The last parameter to this method indicates if an autoincrement column is getting added or if the autoincrement column is being modified to change the increment value or to change the start value
        Parameters:
        columnName - The name of the column
        columnPosition - The ordinal position of the column
        columnType - A DataTypeDescriptor for the type of the column
        columnDefault - A DataValueDescriptor representing the default value of the column, if any (null if no default)
        columnDefaultInfo - The default info for the column.
        table - A TableDescriptor for the table the column is in
        defaultUUID - The UUID for the default, if any.
        autoincStart - Start value for an autoincrement column.
        autoincInc - Increment for autoincrement column
        userChangedWhat - Adding an autoincrement column OR changing increment value or start value of the autoincrement column.
      • ColumnDescriptor

        public ColumnDescriptor​(java.lang.String columnName,
                                int columnPosition,
                                DataTypeDescriptor columnType,
                                DataValueDescriptor columnDefault,
                                DefaultInfo columnDefaultInfo,
                                TableDescriptor table,
                                UUID defaultUUID,
                                long autoincStart,
                                long autoincInc,
                                boolean autoincCycle)
        Constructor for a ColumnDescriptor
        Parameters:
        columnName - The name of the column
        columnPosition - The ordinal position of the column
        columnType - A DataTypeDescriptor for the type of the column
        columnDefault - A DataValueDescriptor representing the default value of the column, if any (null if no default)
        columnDefaultInfo - The default info for the column.
        table - A TableDescriptor for the table the column is in
        defaultUUID - The UUID for the default, if any.
        autoincStart - Start value for an autoincrement column.
        autoincInc - Increment for autoincrement column
      • ColumnDescriptor

        public ColumnDescriptor​(java.lang.String columnName,
                                int columnPosition,
                                DataTypeDescriptor columnType,
                                DataValueDescriptor columnDefault,
                                DefaultInfo columnDefaultInfo,
                                UUID uuid,
                                UUID defaultUUID,
                                long autoincStart,
                                long autoincInc,
                                long autoincValue,
                                boolean autoincCycle)
        Constructor for a ColumnDescriptor. Used when columnDescriptor doesn't know/care about a table descriptor.
        Parameters:
        columnName - The name of the column
        columnPosition - The ordinal position of the column
        columnType - A DataTypeDescriptor for the type of the column
        columnDefault - A DataValueDescriptor representing the default value of the column, if any (null if no default)
        columnDefaultInfo - The default info for the column.
        uuid - A uuid for the object that this column is in.
        defaultUUID - The UUID for the default, if any.
        autoincStart - Start value for an autoincrement column.
        autoincInc - Increment for autoincrement column
        autoincValue - Current value of the autoincrement column
    • Method Detail

      • getReferencingUUID

        public UUID getReferencingUUID()
        Get the UUID of the object the column is a part of.
        Returns:
        The UUID of the table the column is a part of.
      • getTableDescriptor

        public TableDescriptor getTableDescriptor()
        Get the TableDescriptor of the column's table.
        Returns:
        The TableDescriptor of the column's table.
      • getColumnName

        public java.lang.String getColumnName()
        Get the name of the column.
        Returns:
        A String containing the name of the column.
      • setColumnName

        public void setColumnName​(java.lang.String newColumnName)
        Sets the column name in case of rename column.
        Parameters:
        newColumnName - The new column name.
      • setTableDescriptor

        public void setTableDescriptor​(TableDescriptor tableDescriptor)
        Sets the table descriptor for the column.
        Parameters:
        tableDescriptor - The table descriptor for this column
      • getPosition

        public int getPosition()
        Get the ordinal position of the column (1 based)
        Returns:
        The ordinal position of the column.
      • getType

        public DataTypeDescriptor getType()
        Get the TypeDescriptor of the column's datatype.
        Returns:
        The TypeDescriptor of the column's datatype.
      • hasNonNullDefault

        public boolean hasNonNullDefault()
        Return whether or not there is a non-null default on this column.
        Returns:
        Whether or not there is a non-null default on this column.
      • getDefaultValue

        public DataValueDescriptor getDefaultValue()
        Get the default value for the column. For columns with primitive types, the object returned will be of the corresponding object type. For example, for a float column, getDefaultValue() will return a Float.
        Returns:
        An object with the value and type of the default value for the column. Returns NULL if there is no default.
      • getDefaultInfo

        public DefaultInfo getDefaultInfo()
        Get the DefaultInfo for this ColumnDescriptor.
        Returns:
        The DefaultInfo for this ColumnDescriptor.
      • getDefaultUUID

        public UUID getDefaultUUID()
        Get the UUID for the column default, if any.
        Returns:
        The UUID for the column default, if any.
      • getDefaultDescriptor

        public DefaultDescriptor getDefaultDescriptor​(DataDictionary dd)
        Get a DefaultDescriptor for the default, if any, associated with this column.
        Parameters:
        dd - The DataDictionary.
        Returns:
        A DefaultDescriptor if this column has a column default.
      • isAutoincrement

        public boolean isAutoincrement()
        Is this column an autoincrement column?
        Returns:
        Whether or not this is an autoincrement column
      • updatableByCursor

        public boolean updatableByCursor()
      • hasGenerationClause

        public boolean hasGenerationClause()
        Is this column a generated column
      • isAutoincAlways

        public boolean isAutoincAlways()
        Is this column to have autoincremented value always ?
      • getAutoincStart

        public long getAutoincStart()
        Get the start value of an autoincrement column
        Returns:
        Get the start value of an autoincrement column
      • getAutoincCycle

        public boolean getAutoincCycle()
      • getAutoincInc

        public long getAutoincInc()
        Get the Increment value given by the user for an autoincrement column
        Returns:
        the Increment value for an autoincrement column
      • getAutoincValue

        public long getAutoincValue()
        Get the current value for an autoincrement column. One case in which this is used involves dropping a column from a table. When ALTER TABLE DROP COLUMN runs, it drops the column from SYSCOLUMNS, and then must adjust the column positions of the other subsequent columns in the table to account for the removal of the dropped columns. This involves deleting and re-adding the column descriptors to SYSCOLUMNS, but during that process we must be careful to preserve the current value of any autoincrement column.
        Returns:
        the current value for an autoincrement column
      • getAutoinc_create_or_modify_Start_Increment

        public long getAutoinc_create_or_modify_Start_Increment()
      • setAutoinc_create_or_modify_Start_Increment

        public void setAutoinc_create_or_modify_Start_Increment​(int c_or_m)
      • setPosition

        public void setPosition​(int columnPosition)
        Set the ordinal position of the column.
      • toString

        public java.lang.String toString()
        Convert the ColumnDescriptor to a String.
        Overrides:
        toString in class java.lang.Object
        Returns:
        A String representation of this ColumnDescriptor
      • assertAutoinc

        private static void assertAutoinc​(boolean autoinc,
                                          long autoincInc,
                                          DefaultInfo defaultInfo)