大数据就业实战培训 Oracle就业实战培训
Oracle OCP 19c 认证1Z0-082考试题库(第24题)-CUUG内部学员版082题库解析
24、Evaluate these commands which execute successfully:
CREATE SEQUENCE ord_seq
INCREMENT BY 1
START WITH 1
MAXVALUE 100000
CYCLE
CACHE 5000;
CREATE TABLE ord_items(
ord_no NUMBER(4) DEFAULT ord_seq.NEXTVALUE NOT NULL,
item_no NUMBER(3),
qty NUMBER(3),
expiry_date DATE,
CONSTRAINT it_pk PRIMARY KEY(ord_no,item_no),
CONSTRAINIT ord_fk FOREIGN KEY(ord_no) REFERENCES orders (ord_no));
Which two statements are true about the ORD_ITEMS table and the ORD_SEQ sequence? (Choose two.)
A. If sequence ORD_SEQ is dropped then the default value for column ORD_NO will be NULL for rows inserted into ORD_ITEMS
B. Any user inserting rows into table ORD_ITEMS must have been granted access to sequence ORD_SEQ
C. Column ORD_NO gets the next number from sequence ORD_SEQ whenever a row is inserted into ORD_ITEMS and no explicit value is given for ORD_NO
D. Sequence ORD_SEQ cycles back to 1 after every 5000 numbers and can cycle 20 times
E. Sequence ORD_SEQ is guaranteed not to generate duplicate numbers
