Hi MonetDB, I think I'm really confused or I found a bug. Please have a look below. I'm expecting a 'aggregation_book_contact_id_fkey' violation, since that row is clearly missing. But I'm getting a 'aggregation_book.aggregation_book_publisher_id_fkey' violation. Is it me or is this error message wrong? sql>\d sys.aggregation_book CREATE TABLE "sys"."aggregation_book" ( "id" INTEGER NOT NULL DEFAULT next value for "sys"."seq_6205", "isbn" VARCHAR(9) NOT NULL, "name" VARCHAR(255) NOT NULL, "pages" INTEGER NOT NULL, "rating" DOUBLE NOT NULL, "price" DECIMAL(6,2) NOT NULL, "contact_id" INTEGER NOT NULL, "publisher_id" INTEGER NOT NULL, "pubdate" DATE NOT NULL, CONSTRAINT "aggregation_book_id_pkey" PRIMARY KEY ("id"), CONSTRAINT "aggregation_book_contact_id_fkey" FOREIGN KEY ("contact_id") REFERENCES "sys"."aggregation_author" ("id"), CONSTRAINT "aggregation_book_publisher_id_fkey" FOREIGN KEY ("publisher_id") REFERENCES "sys"."aggregation_publisher" ("id") ); sql>select * from aggregation_publisher; +------+--------+------------+ | id | name | num_awards | +======+========+============+ | 1 | Apress | 3 | +------+--------+------------+ 1 tuple (0.588ms) sql>select * from aggregation_author; +----+------+-----+ | id | name | age | +====+======+=====+ +----+------+-----+ 0 tuples (0.570ms) sql>INSERT INTO "aggregation_book" ("id", "isbn", "name", "pages", more>"rating", "price", "contact_id", "publisher_id", "pubdate") VALUES (1, more>'159059725', 'The Definitive Guide to Django: Web Development Done more>Right', 447, 4.5, '30.00', 1, 1, '2007-12-06'); INSERT INTO: FOREIGN KEY constraint 'aggregation_book.aggregation_book_publisher_id_fkey' violated -- Gijs Molenaar http://www.astro.uva.nl/people/gijs-molenaar/