hello,
I tried to create a foreign key but I always get this error:

violation of FOREIGN KEY constraint "".
violation of FOREIGN KEY constraint "FK_RES_TREEVIEW_1" on table "RES_TREEVIEW".
Foreign key reference target does not exist.

here is my two tables DDL:

CREATE TABLE STYLES (
STYLE_ID INTEGER DEFAULT -1 NOT NULL,
STYLE_NAME VARCHAR(80) NOT NULL,
BACK_COLOR VARCHAR(35),
BACK_COLOR_ENABLED SMALLINT DEFAULT 0,
FONT_STYLE_IS_UNDER SMALLINT DEFAULT 0,
FONT_STYLE_IS_STRIKE SMALLINT DEFAULT 0,
BITMAP_IMAGE BLOB SUB_TYPE 0 SEGMENT SIZE 80
);

ALTER TABLE STYLES ADD CONSTRAINT PK_STYLES1 PRIMARY KEY (STYLE_ID);

===============================================================

CREATE TABLE RES_TREEVIEW (
FOLDER_ID BIGINT NOT NULL,
FOLDER_PARENT_ID BIGINT NOT NULL,
FOLDER_NAME VARCHAR(100) NOT NULL,
FOLDER_POSITION BIGINT NOT NULL,
FOLDER_IMAGE_INDEX SMALLINT,
FOLDER_FLAG BLOB SUB_TYPE 0 SEGMENT SIZE 80,
FOLDER_ICON BLOB SUB_TYPE 0 SEGMENT SIZE 80,
IS_FOLDER_CUSTOM_ICON SMALLINT DEFAULT 0,
STYLE_ID INTEGER DEFAULT -1
);

ALTER TABLE RES_TREEVIEW ADD CONSTRAINT PK_RES_TREEVIEW PRIMARY KEY (FOLDER_ID);

alter table RES_TREEVIEW
add constraint FK_RES_TREEVIEW_1
foreign key (STYLE_ID)
references STYLES(STYLE_ID)
on delete SET DEFAULT
on update CASCADE

========================================================
any advice ?

Thanks