Firebird 2.1 Language Reference Update

ALTER COLUMN: SET DEFAULT
Available in: DSQL
Added in: 2.0
DDL statements
Description: Firebird 2 adds the possibility to set/alter defaults on existing columns. If the column already had
a default, the new default will replace it. Column-level defaults always override domain-level defaults.
Syntax:
Example:
ALTER TABLE tablename ALTER [COLUMN] colname SET DEFAULT
::= literal-value | context-variable | NULL
alter table Customers alter EnteredBy set default current_user
Tip
If you want to switch off a domain-based default on a column, set the column default to NULL.
ALTER COLUMN: POSITION now 1-based
Changed in: 1.0
Description: When changing a column's position, the engine now interprets the new position as 1-based. This
is in accordance with the SQL standard and the InterBase documentation, but in practice InterBase interpreted
the position as 0-based.
Syntax:
Example:
ALTER TABLE tablename ALTER [COLUMN] colname POSITION
::= an integer between 1 and the number of columns
alter table Stock alter Quantity position 3
Note
Don't confuse this with the POSITION in CREATE/ALTER TRIGGER. Trigger positions are and will remain 0based.
CHECK accepts NULL outcome
Changed in: 2.0
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