ADD
should surround each column definition. You don't wrap a single ADD
around 3 new columns.
See: http://docs.oracle.com/cd/B28359_01/server.111/b28286/statements_3001.htm#i2183462
For Primary Key and Foreign Key constraints you need the CONSTRAINT
keyword. See: http://docs.oracle.com/javadb/10.3.3.0/ref/rrefsqlj81859.html Section on "adding constraints".
EDIT: This was the only thing that worked on the fiddle I tried:
ALTER TABLE table7
ADD (
CONSTRAINT pk1 PRIMARY KEY (column1),
CONSTRAINT fk1 Foreign Key (column2) REFERENCES Table1 (column2),
CONSTRAINT fk2 Foreign Key (column3) REFERENCES Service (column3)
)
Here's the fiddle: http://sqlfiddle.com/#!4/9d2a3