Add clause: columns

Purpose

Use the Add clause to add a column to an existing table. It is optional.

This clause adds a column to the table. It defines a column with the same syntax as the Create Table command (see "Column definition for remote tables").

Syntax

ADD [COLUMN] column_nameDatatype ... [DEFAULT default_value] [[NOT]NULL] [EXT_ID] [PRIMARY KEY] [START WITH starting_value]

default_value

is the default value to be assigned to the column. See "Column definition for remote tables" for details.

starting_value

is the starting value for the Identity column. The default start value is 0.

Notes

• If NOT NULL is specified and the table is not empty, a default value must be specified. In all other respects, this command is the equivalent of a column definition in a Create Table statement.
• You cannot specify ANYTYPE, BINARY, COMBOBOX, or TIME data types in the column definition of Alter Table statements.
• If a SQL view includes SELECT * FROM for the table to which the column was added in the view’s Select statement, the new column is added to the view.

Example A

Assuming the current schema is SFORCE, this example adds the status column with a default value of ACTIVE to the test table.

Example B

Assuming the current schema is SFORCE, this example adds a deptId column that can be used as a foreign key column.

ALTER TABLE test ADD COLUMN deptId TEXT(18)