SELLDATE를 DATE자료형으로 잡았는데..
자꾸 컨버전이 안된다면서...
테이블 생성한 SQL은
/* Domain definitions */
CREATE DOMAIN "NEW_DOMAIN" AS CHAR(15) CHARACTER SET KSC_5601 NOT NULL;

/* Table: SELL_LIST, Owner: SYSDBA */

CREATE TABLE "SELL_LIST"
(
  "SELLDATE"    DATE NOT NULL,
  "CUST_NO"    SMALLINT NOT NULL,
  "ISBN"    INTEGER NOT NULL,
  "EA"    SMALLINT,
  "TOTAL_PRICE"    SMALLINT,
  "CANCELED"    CHAR(6) CHARACTER SET KSC_5601,
  "CUSTOMER"    "NEW_DOMAIN" NOT NULL,
PRIMARY KEY ("SELLDATE", "CUST_NO", "ISBN")
);
입니다.