Db2 Developer-C 11.1

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CREATE TABLE a (
    id INT NOT NULL,
    PRIMARY KEY (id)
);




CREATE TABLE b (
    id INT NOT NULL,
    a INT NOT NULL,
    PRIMARY KEY (id),
    constraint b_2_a FOREIGN KEY (a) REFERENCES a (id) ON DELETE CASCADE
);

CREATE TABLE c (
    id INT NOT NULL,
    a INT NOT NULL,
    PRIMARY KEY (id),
    constraint c_2_a FOREIGN KEY (a) REFERENCES a (id) ON DELETE CASCADE
);

CREATE TABLE d (
    id INT NOT NULL,
    b INT NOT NULL,
    c INT NOT NULL,
    PRIMARY KEY (id)
   , constraint d_2_b FOREIGN KEY (id) REFERENCES b (id) ON DELETE RESTRICT
   , constraint d_2_c FOREIGN KEY (id) REFERENCES c (id) ON DELETE  cascade
);
[IBM][CLI Driver][DB2/LINUXX8664] SQL20255N  FOREIGN KEY "D_2_C" is not valid because it would cause a descendent table "FIDDLE_AHM" to be delete-connected to its ancestor table "FIDDLE_AHM" through multiple relationships with conflicting delete rules. The conflict is between the delete rules of constraints "FIDDLE_AHM" and "FIDDLE_AHMYBRMRQWXVUEZOGSLL.D" on the descendent table. Reason code = "3".  SQLSTATE=42915 SQLCODE=-20255