This command provides the following functions:
Adds new columns
Adds, changes, or drops constraints
Partitions or unpartitions an existing table
Transact-SQL Syntax
alter table [database.[owner].]table_name
{add column_name datatype
[default {constant_expression | user | null}]
{[{identity | null}]
| [[constraint constraint_name]
{{unique | primary key}
[clustered | nonclustered]
[with {fillfactor | max_rows_per_page} = x]
[on segment_name]
[references [[database.]owner.]ref_table
[(ref_column)]
| check (search_condition)}]}...
{[, next_column]}...
| add {[constraint constraint_name]
{unique | primary key}
[clustered | nonclustered]
(column_name [{, column_name}...])
[with {fillfactor | max_rows_per_page} = x]
[on segment_name]
| foreign key (column_name [{, column_name}...])
references [[database.]owner.]ref_table
[(ref_column [{, ref_column}...])]
| check (search_condition)}
| drop constraint constraint_name
| replace column_name
default {constant_expression | user | null}
| partition number_of_partitions
| unpartition}
ODBC Syntax
ALTER TABLE base_table_name
{ADD column_identifier datatype
|ADD(column_identifier datatype[,column_identifier datatype]...)
|DROP[COLUMN]column_identifier[CASCADE|RESTRICT]}
specifies that you should assign a NULL value when a value is not provided during an insertion.
is the name of the table to be changed.
is the name of a column to be added.
is any of the system datatypes except Bit. If the transformation mode is passthrough, the datatype is expressed as an ODBC datatype.
indicates that you can include additional column definitions separated by commas, using the same syntax described for a column definition.
alter table publishers
add manager_name varchar(40) null
This adds the manager_name column to the publishers table. For each existing table row, a NULL value is assigned to the new column.
ASE/CIS sends the alter table command to DirectConnect as a language event.
The following are not supported:
add constraint
drop constraint
replace column name
partition | unpartition
Transformation adds parentheses when the add column option includes more than one column.
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