ALTER TABLE

This statement alters the definition of a table.

To support ALTER TABLE processing, the IP GETSUPPORT operation must return TRUE for IP_SUPPORT_ALTER_TABLE.

Syntax

ALTER TABLE table_name alter-table-action

alter-table-action = ADD [COLUMN] column-definition

| ADD (column-definition [,column-definition]…)

| DROP [COLUMN] column-identifier

| ALTER [COLUMN] column-identifier

SET DEFAULT default-value

| ALTER [COLUMN] column-identifier DROP DEFAULT

| ADD CONSTRAINT constraint-name UNQIUE

(column-identifier)

| DROP CONSTRAINT

column-definition = column-identifier data-type

[DEFAULT default-value]

[column-constraint [column-constraint]...]

column-constraint = NOT NULL | UNIQUE [KEY]

ALTER TABLE Qual.Own.emp ADD COLUMN ID INTEGER;

ALTER TABLE Qual.Own.emp ALTER COLUMN ID SET DEFAULT 10;

ALTER TABLE Qual.Own.emp ALTER COLUMN ID DROP DEFAULT;

ALTER TABLE Qual.Own.emp ADD CONSTRAINT unique_constraint UNIQUE (ID);