Class ColumnDescriptor

java.lang.Object
org.apache.derby.iapi.sql.dictionary.TupleDescriptor
org.apache.derby.iapi.sql.dictionary.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 Details

    • columnDefaultInfo

      private DefaultInfo columnDefaultInfo

    • table

      private TableDescriptor table

    • columnName

      private String columnName

    • columnPosition

      private int columnPosition

    • columnType

      private DataTypeDescriptor columnType

    • columnDefault

      private DataValueDescriptor columnDefault

    • 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 Details

    • ColumnDescriptor

      public ColumnDescriptor(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(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(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 Details

    • 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 String getColumnName()
      Get the name of the column.
      Returns:
      A String containing the name of the column.

    • setColumnName

      public void setColumnName(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 String toString()
      Convert the ColumnDescriptor to a String.
      Overrides:
      toString in class Object
      Returns:
      A String representation of this ColumnDescriptor

    • getDescriptorName

      public String getDescriptorName()
      Overrides:
      getDescriptorName in class TupleDescriptor
      See Also:

    • getDescriptorType

      public String getDescriptorType()
      Description copied from class: TupleDescriptor
      Each descriptor must identify itself with its type; i.e index, check constraint whatever.
      Overrides:
      getDescriptorType in class TupleDescriptor
      See Also:

    • assertAutoinc

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