E. Alter a table to add several columns with constraints This example adds several columns with constraints defined with the new column. The first new column has an IDENTITY property; each row in the table has new incremental values in the identity column. CREATE TABLE doc_exe ( column_a INT CONSTRAINT column_a_un UNIQUE) GO ALTER TABLE doc_exe ADD /* Add a PRIMARY KEY identity column. */ column_b INT IDENTITY CONSTRAINT column_b_pk PRIMARY KEY, /* Add a column referencing another column in the same table. */ column_c INT NULL CONSTRAINT column_c_fk REFERENCES doc_exe(column_a), /* Add a column with a constraint to enforce that */ /* nonnull data is in a valid phone number format. */ column_d VARCHAR(16) NULL CONSTRAINT column_d_chk CHECK (column_d IS NULL OR column_d LIKE "[0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]" OR column_d LIKE "([0-9][0-9][0-9]) [0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]"), /* Add a nonnull column with a default. */ column_e DECIMAL(3,3) CONSTRAINT column_e_default DEFAULT .081 GO EXEC sp_help doc_exe GO DROP TABLE doc_exe GOKurt