[SQL] Alternative to Select in table check constraint

[Richard Broersma Jr]

I am practicing with SQL examples comming from the book:

JOE CELKO'S
SQL
PUZZLES
& ANSWERS

The following codes doesn't work on PostgreSQL 8.1.4 but according to the book 
does conform to
SQL-92.  Is there any other solutions that would result in the same effect?  Or 
is this an example
of a contraint that should be avoided at all costs?

CREATE TABLE BADGES
(
        BADGENO         SERIAL NOT NULL PRIMARY KEY,
        EMPNO           INTEGER NOT NULL REFERENCES SECEMPLOYEES (EMPNO),
        ISSUEDATE       DATE NOT NULL,
        STATUS          CHAR(1) NOT NULL CHECK ( STATUS IN ('A', 'I')),

        CHECK   ( 1 = ALL (     SELECT COUNT(STATUS)
                                FROM BADGES
                                WHERE STATUS = 'A'
                                GROUP BY EMPNO))
);


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