Alter Table

Modify table schemas in Airport-attached databases using ALTER TABLE statements for adding, removing, and renaming columns.

The Airport extension supports table schema modifications through the standard SQL ALTER TABLE statement. The Arrow Flight server determines whether to permit and apply the requested alteration.

Example

For a DuckDB session to alter a table, a standard SQL ALTER TABLE statement is executed in a schema that is managed by the Airport extension.

-- Attach an Airport database
ATTACH 'example' (TYPE AIRPORT, location 'grpc://localhost:50312/');

-- Assume that there is a `main` schema
-- already in the `example` database
CREATE TABLE example.main.employees (
  name varchar,
  id integer
);

ALTER TABLE example.main.employees DROP COLUMN id;

Arrow Flight Server Implementation Notes

The Airport extension invokes a DoAction Arrow Flight RPC with an action name corresponding to the specific alteration type.

Supported Alteration Operations

Action Name	Description
add_column	Add a column to a table.
add_constraint	Add a constraint to a field.
add_field	Add a field to a structure.
change_column_type	Change the type of a column.
drop_not_null	Drop NOT NULL constraint from a field.
remove_column	Remove a column from a table.
remove_field	Remove a field from a structure.
rename_column	Rename a column.
rename_field	Rename a field in a structure.
rename_table	Rename a table.
set_default	Set a default value for a field.
set_not_null	Set a field to NOT NULL.

Each alteration type accepts a specific parameter structure as defined in its respective documentation page.

Return Value: Most alteration actions return an updated FlightInfo structure reflecting the modified table schema. Actions like set_default and set_not_null do not return values but must raise an Arrow Flight exception on error.