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).
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.
ALTER TABLE test ADD COLUMN status TEXT(30) DEFAULT 'ACTIVE'
Example B
Assuming the current schema is SFORCE, this example adds a deptId column that can be used as a foreign key column.
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.