下面是我的数据表:
CREATE TABLE customer_wer (
id_customer NUMBER,
name VARCHAR2(10),
surname VARCHAR2(20),
date_from DATE,
date_to DATE);
--KAROLINA BIELAWSKA - GAP MAR APR 2000 and JUN JUL 2001
INSERT INTO customer_wer VALUES (2, 'Karolina', 'Bielawska', '01-JAN-00', '28-MAR-00');
INSERT INTO customer_wer VALUES (2, 'Karolina', 'Bielawska', '01-APR-00', '30-JUN-00');
INSERT INTO customer_wer VALUES (2, 'Karolina', 'Bielawska', '01-JUL-00', '30-SEP-00');
INSERT INTO customer_wer VALUES (2, 'Karolina', 'Bielawska', '01-OCT-00', '31-DEC-00');
INSERT INTO customer_wer VALUES (2, 'Karolina', 'Bielawska', '01-JAN-01', '31-MAR-01');
INSERT INTO customer_wer VALUES (2, 'Karolina', 'Bielawska', '01-APR-01', '15-JUN-01'); …Run Code Online (Sandbox Code Playgroud) 我有以下表格和数据:
CREATE TABLE customer_wer(
id_customer NUMBER,
name VARCHAR2(10),
surname VARCHAR2(20),
date_from DATE,
date_to DATE NOT NULL,
CONSTRAINT customer_wer_pk PRIMARY KEY (id_customer, data_from));
INSERT INTO customer_wer VALUES (4, 'Karolina', 'Komuda', '01-JAN-00', '31-MAR-00');
INSERT INTO customer_wer VALUES (4, 'Karolina', 'Komuda', '01-APR-00', '30-JUN-00');
INSERT INTO customer_wer VALUES (4, 'Karolina', 'Komuda', '15-JUN-00', '30-SEP-00');
INSERT INTO customer_wer VALUES (4, 'Karolina', 'Komuda', '01-OCT-00', '31-DEC-00');
INSERT INTO customer_wer VALUES (4, 'Karolina', 'Komuda', '01-JAN-01', '31-MAR-01');
INSERT INTO customer_wer VALUES (4, 'Karolina', 'Komuda', '01-APR-01', '30-JUN-01');
INSERT INTO customer_wer VALUES …Run Code Online (Sandbox Code Playgroud)