alter_column

alter_column(column_name: str, nullable: Optional[bool] = None, comment: bool = False, server_default: Union[Function, bool] = False, new_column_name: Optional[str] = None, type_: Optional[Union[TypeEngine, Type[TypeEngine]]] = None, existing_type: Optional[Union[TypeEngine, Type[TypeEngine]]] = None, existing_server_default: bool = False, existing_nullable: None = None, existing_comment: None = None, insert_before: None = None, insert_after: None = None, **kw) → Optional[Table]

Issue an “alter column” instruction using the current batch migration context.

Parameters are the same as that of Operations.alter_column(), as well as the following option(s):

Parameters:

• insert_before – String name of an existing column which this column should be placed before, when creating the new table.

  New in version 1.4.0.

• insert_after – String name of an existing column which this column should be placed after, when creating the new table. If both BatchOperations.alter_column.insert_before and BatchOperations.alter_column.insert_after are omitted, the column is inserted after the last existing column in the table.

  New in version 1.4.0.

See also:

• Operations.alter_column()