H2, Spring Data with Hibernate 6. I like to control the “primary key” definition when I am using a @JoinTablein my java model. The issue Hibernate seems to create automatically two separate primary key definitions instead of a single one where both foreign key columns get considered.

e.g. I have a “Layout” and “Module” class, where layouts can have multiple times and instance of the same “module” (Many-to-Many relationship).

@Entity
@Table(name="`layouts`")
@Data
public class Layout {

    @Id
    @GeneratedValue
    private Integer id;

    @ManyToMany(fetch = FetchType.LAZY)
    @JoinTable(name = "layout_modules", joinColumns = { @JoinColumn(name = "layout_id") }, inverseJoinColumns = { @JoinColumn(name = "module_id") })
    @OrderColumn(name = "sort", columnDefinition = "integer default 0", nullable = true)
    private List<Module> modules = new ArrayList<>();
}

Based on the @JoinTable Hibernate generates the “layout_modules” table with two “PRIMARY KEY” Definitions.

Current Generated DDL

CREATE TABLE "shop"."layout_modules" (
    "layout_id" INTEGER NOT NULL,
    "module_id" INTEGER NOT NULL,
    "sort" INTEGER DEFAULT 0 NOT NULL,
    CONSTRAINT "FKg1usbavp8i4rarv3unyx83fnq" PRIMARY KEY ("layout_id"),
    CONSTRAINT "FKo1sjor3ruyi04m7dfurkgn4ru" PRIMARY KEY ("module_id"),
    CONSTRAINT "FKg1usbavp8i4rarv3unyx83fnq" FOREIGN KEY ("layout_id") REFERENCES "shop"."layouts"("id") ON DELETE RESTRICT ON UPDATE RESTRICT,
    CONSTRAINT "FKo1sjor3ruyi04m7dfurkgn4ru" FOREIGN KEY ("module_id") REFERENCES "shop"."modules"("id") ON DELETE RESTRICT ON UPDATE RESTRICT
);
CREATE INDEX "FKg1usbavp8i4rarv3unyx83fnq_INDEX_8" ON "shop"."layout_modules" ("layout_id");
CREATE INDEX "FKo1sjor3ruyi04m7dfurkgn4ru_INDEX_8" ON "shop"."layout_modules" ("module_id");

BUT I like that only one single “PRIMARY KEY” definition should be created instead. Any idea how I can influence or enforce that?

If not easily possible can I somehow enforce that for @JoinTable no primary key definitions get automatically created?

Expected DDL which I like to have generated

CREATE TABLE "shop"."layout_modules" (
    "layout_id" INTEGER NOT NULL,
    "module_id" INTEGER NOT NULL,
    "sort" INTEGER DEFAULT 0 NOT NULL,
    CONSTRAINT LAYOUT_MODULES_PK PRIMARY KEY ("layout_id","module_id"),
    CONSTRAINT "FKg1usbavp8i4rarv3unyx83fnq" FOREIGN KEY ("layout_id") REFERENCES "shop"."layouts"("id") ON DELETE RESTRICT ON UPDATE RESTRICT,
    CONSTRAINT "FKo1sjor3ruyi04m7dfurkgn4ru" FOREIGN KEY ("module_id") REFERENCES "shop"."modules"("id") ON DELETE RESTRICT ON UPDATE RESTRICT
);
CREATE UNIQUE INDEX PRIMARY_KEY_8 ON "shop"."layout_modules" ("layout_id","module_id");
CREATE INDEX "FKg1usbavp8i4rarv3unyx83fnq_INDEX_8" ON "shop"."layout_modules" ("layout_id");
CREATE INDEX "FKo1sjor3ruyi04m7dfurkgn4ru_INDEX_8" ON "shop"."layout_modules" ("module_id");