CREATE TABLE AA (
  aa_id integer NOT NULL PRIMARY KEY
  ,bb_id integer NOT NULL  
  ,CONSTRAINT c_bb_id FOREIGN KEY(bb_id)
    REFERENCES bb(id) ON DELETE NO ACTION
  )  ;


CREATE TABLE BB (
  bb_id integer NOT NULL PRIMARY KEY
  ,aa_id integer NOT NULL  
  ,CONSTRAINT c_aa_id FOREIGN KEY(aa_id)
    REFERENCES aa(id) ON DELETE NO ACTION
  )  ;

CREATE TABLE AA (
    AA_ID  INTEGER NOT NULL,
    BB_ID  INTEGER NOT NULL
);

CREATE TABLE BB (
    BB_ID  INTEGER NOT NULL,
    AA_ID  INTEGER NOT NULL
);

ALTER TABLE AA ADD PRIMARY KEY (AA_ID);
ALTER TABLE BB ADD PRIMARY KEY (BB_ID);

ALTER TABLE AA ADD CONSTRAINT C_BB_ID FOREIGN KEY (BB_ID) REFERENCES BB (BB_ID);
ALTER TABLE BB ADD CONSTRAINT C_AA_ID FOREIGN KEY (AA_ID) REFERENCES AA (AA_ID);