Restricting Access to Specific Columns

Unlike GRANT, the REVOKE statement has no syntax to specify privileges on a subset of columns in a table. To revoke the Select, Update, or References privilege on a column from a user, you must revoke the privilege for all the columns of the table. To provide access to some of the columns on which you previously had granted privileges, issue a new GRANT statement to restore the appropriate privilege on specific columns.

REVOKE SELECT ON customer FROM PUBLIC;
GRANT SELECT (fname, lname, company, city) ON customer TO PUBLIC;

GRANT REFERENCES (fname, lname, company, city) ON customer TO mary;
REVOKE REFERENCES ON customer FROM mary;
GRANT REFERENCES (company, city) ON customer TO mary;