Oracle 自连接
Oracle Self-Join
我正在处理一些自连接示例，但我在下面的示例中画了一个空白。下面是最后一个例子 link Self-Join Example
SELECT
e1.hire_date,
(e1.first_name || ' ' || e1.last_name) employee1,
(e2.first_name || ' ' || e2.last_name) employee2
FROM
employees e1
INNER JOIN employees e2 ON
e1.employee_id > e2.employee_id
AND e1.hire_date = e2.hire_date
ORDER BY
e1.hire_date DESC,
employee1,
employee2;
我不明白为什么我需要检查第一个员工实例的 Employee_id 是否大于第二个员工实例的 employee_id。
如果有人能对此提供一个很好的解释，将不胜感激。
需要 create/insert 个脚本。
CREATE TABLE employees
(
employee_id NUMBER
GENERATED BY DEFAULT AS IDENTITY START WITH 108
PRIMARY KEY,
first_name VARCHAR( 255 ) NOT NULL,
last_name VARCHAR( 255 ) NOT NULL,
email VARCHAR( 255 ) NOT NULL,
phone VARCHAR( 50 ) NOT NULL ,
hire_date DATE NOT NULL ,
manager_id NUMBER( 12, 0 ) , -- fk
job_title VARCHAR( 255 ) NOT NULL,
CONSTRAINT fk_employees_manager
FOREIGN KEY( manager_id )
REFERENCES employees( employee_id )
ON DELETE CASCADE
);
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (107,'Summer','Payne','summer.payne@example.com','515.123.8181',to_date('07-JUN-16','DD-MON-RR'),106,'Public Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (106,'Rose','Stephens','rose.stephens@example.com','515.123.8080',to_date('07-JUN-16','DD-MON-RR'),2,'Accounting Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (101,'Annabelle','Dunn','annabelle.dunn@example.com','515.123.4444',to_date('17-SEP-16','DD-MON-RR'),2,'Administration Assistant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (1,'Tommy','Bailey','tommy.bailey@example.com','515.123.4567',to_date('17-JUN-16','DD-MON-RR'),null,'President');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (3,'Blake','Cooper','blake.cooper@example.com','515.123.4569',to_date('13-JAN-16','DD-MON-RR'),1,'Administration Vice President');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (2,'Jude','Rivera','jude.rivera@example.com','515.123.4568',to_date('21-SEP-16','DD-MON-RR'),1,'Administration Vice President');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (11,'Tyler','Ramirez','tyler.ramirez@example.com','515.124.4269',to_date('28-SEP-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (10,'Ryan','Gray','ryan.gray@example.com','515.124.4169',to_date('16-AUG-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (14,'Elliot','Brooks','ellibrooks@example.com','515.124.4567',to_date('07-DEC-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (12,'Elliott','James','elliott.james@example.com','515.124.4369',to_date('30-SEP-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (13,'Albert','Watson','albert.watson@example.com','515.124.4469',to_date('07-MAR-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (9,'Mohammad','Peterson','mohammad.peterson@example.com','515.124.4569',to_date('17-AUG-16','DD-MON-RR'),2,'Finance Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (104,'Harper','Spencer','harper.spencer@example.com','515.123.7777',to_date('07-JUN-16','DD-MON-RR'),2,'Human Resources Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (4,'Louie','Richardson','louie.richardson@example.com','590.423.4567',to_date('03-JAN-16','DD-MON-RR'),3,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (5,'Nathan','Cox','nathan.cox@example.com','590.423.4568',to_date('21-MAY-16','DD-MON-RR'),4,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (8,'Bobby','Torres','bobby.torres@example.com','590.423.5567',to_date('07-FEB-16','DD-MON-RR'),4,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (7,'Charles','Ward','charles.ward@example.com','590.423.4560',to_date('05-FEB-16','DD-MON-RR'),4,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (6,'Gabriel','Howard','gabriel.howard@example.com','590.423.4569',to_date('25-JUN-16','DD-MON-RR'),4,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (102,'Emma','Perkins','emma.perkins@example.com','515.123.5555',to_date('17-FEB-16','DD-MON-RR'),1,'Marketing Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (103,'Amelie','Hudson','amelie.hudson@example.com','603.123.6666',to_date('17-AUG-16','DD-MON-RR'),102,'Marketing Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (105,'Gracie','Gardner','gracie.gardner@example.com','515.123.8888',to_date('07-JUN-16','DD-MON-RR'),2,'Public Relations Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (17,'Frederick','Price','frederick.price@example.com','515.127.4563',to_date('24-DEC-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (16,'Alex','Sanders','alex.sanders@example.com','515.127.4562',to_date('18-MAY-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (18,'Ollie','Bennett','ollie.bennett@example.com','515.127.4564',to_date('24-JUL-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (19,'Louis','Wood','louis.wood@example.com','515.127.4565',to_date('15-NOV-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (20,'Dexter','Barnes','dexter.barnes@example.com','515.127.4566',to_date('10-AUG-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (15,'Rory','Kelly','rory.kelly@example.com','515.127.4561',to_date('07-DEC-16','DD-MON-RR'),1,'Purchasing Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (49,'Isabella','Cole','isabella.cole@example.com','011.44.1344.619268',to_date('15-OCT-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (48,'Jessica','Woods','jessica.woods@example.com','011.44.1344.429278',to_date('10-MAR-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (47,'Ella','Wallace','ella.wallace@example.com','011.44.1344.467268',to_date('05-JAN-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (46,'Ava','Sullivan','ava.sullivan@example.com','011.44.1344.429268',to_date('01-OCT-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (50,'Mia','West','mia.west@example.com','011.44.1344.429018',to_date('29-JAN-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (56,'Evie','Harrison','evie.harrison@example.com','011.44.1344.486508',to_date('23-NOV-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (57,'Scarlett','Gibson','scarlett.gibson@example.com','011.44.1345.429268',to_date('30-JAN-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (58,'Ruby','Mcdonald','ruby.mcdonald@example.com','011.44.1345.929268',to_date('04-MAR-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (59,'Chloe','Cruz','chloe.cruz@example.com','011.44.1345.829268',to_date('01-AUG-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (60,'Isabelle','Marshall','isabelle.marshall@example.com','011.44.1345.729268',to_date('10-MAR-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (61,'Daisy','Ortiz','daisy.ortiz@example.com','011.44.1345.629268',to_date('15-DEC-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (62,'Freya','Gomez','freya.gomez@example.com','011.44.1345.529268',to_date('03-NOV-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (80,'Elizabeth','Dixon','elizabeth.dixon@example.com','011.44.1644.429262',to_date('04-JAN-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (64,'Florence','Freeman','florence.freeman@example.com','011.44.1346.229268',to_date('19-MAR-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (65,'Alice','Wells','alice.wells@example.com','011.44.1346.329268',to_date('24-JAN-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (66,'Charlotte','Webb','charlotte.webb@example.com','011.44.1346.529268',to_date('23-FEB-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (67,'Sienna','Simpson','sienna.simpson@example.com','011.44.1346.629268',to_date('24-MAR-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (68,'Matilda','Stevens','matilda.stevens@example.com','011.44.1346.729268',to_date('21-APR-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (69,'Evelyn','Tucker','evelyn.tucker@example.com','011.44.1343.929268',to_date('11-MAR-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (70,'Eva','Porter','eva.porter@example.com','011.44.1343.829268',to_date('23-MAR-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (71,'Millie','Hunter','millie.hunter@example.com','011.44.1343.729268',to_date('24-JAN-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (72,'Sofia','Hicks','sofia.hicks@example.com','011.44.1343.629268',to_date('23-FEB-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (73,'Lucy','Crawford','lucy.crawford@example.com','011.44.1343.529268',to_date('24-MAR-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (74,'Elsie','Henry','elsie.henry@example.com','011.44.1343.329268',to_date('21-APR-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (75,'Imogen','Boyd','imogen.boyd@example.com','011.44.1644.429267',to_date('11-MAY-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (76,'Layla','Mason','layla.mason@example.com','011.44.1644.429266',to_date('19-MAR-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (77,'Rosie','Morales','rosie.morales@example.com','011.44.1644.429265',to_date('24-MAR-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (78,'Maya','Kennedy','maya.kennedy@example.com','011.44.1644.429264',to_date('23-APR-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (79,'Esme','Warren','esme.warren@example.com','011.44.1644.429263',to_date('24-MAY-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (55,'Grace','Ellis','grace.ellis@example.com','011.44.1344.987668',to_date('09-DEC-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (54,'Lily','Fisher','lily.fisher@example.com','011.44.1344.498718',to_date('30-MAR-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (53,'Sophia','Reynolds','sophia.reynolds@example.com','011.44.1344.478968',to_date('20-AUG-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (52,'Sophie','Owens','sophie.owens@example.com','011.44.1344.345268',to_date('24-MAR-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (51,'Poppy','Jordan','poppy.jordan@example.com','011.44.1344.129268',to_date('30-JAN-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (63,'Phoebe','Murray','phoebe.murray@example.com','011.44.1346.129268',to_date('11-NOV-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (85,'Holly','Shaw','holly.shaw@example.com','650.509.1876',to_date('27-JAN-16','DD-MON-RR'),22,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (86,'Emilia','Holmes','emilia.holmes@example.com','650.509.2876',to_date('20-FEB-16','DD-MON-RR'),22,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (87,'Molly','Rice','molly.rice@example.com','650.509.3876',to_date('24-JUN-16','DD-MON-RR'),22,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (88,'Ellie','Robertson','ellie.robertson@example.com','650.509.4876',to_date('07-FEB-16','DD-MON-RR'),22,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (89,'Jasmine','Hunt','jasmine.hunt@example.com','650.505.1876',to_date('14-JUN-16','DD-MON-RR'),23,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (90,'Eliza','Black','eliza.black@example.com','650.505.2876',to_date('13-AUG-16','DD-MON-RR'),23,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (91,'Lilly','Daniels','lilly.daniels@example.com','650.505.3876',to_date('11-JUL-16','DD-MON-RR'),23,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (92,'Abigail','Palmer','abigail.palmer@example.com','650.505.4876',to_date('19-DEC-16','DD-MON-RR'),23,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (93,'Georgia','Mills','georgia.mills@example.com','650.501.1876',to_date('04-FEB-16','DD-MON-RR'),24,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (94,'Maisie','Nichols','maisie.nichols@example.com','650.501.2876',to_date('03-MAR-16','DD-MON-RR'),24,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (95,'Eleanor','Grant','eleanor.grant@example.com','650.501.3876',to_date('01-JUL-16','DD-MON-RR'),24,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (96,'Hannah','Knight','hannah.knight@example.com','650.501.4876',to_date('17-MAR-16','DD-MON-RR'),24,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (97,'Harriet','Ferguson','harriet.ferguson@example.com','650.507.9811',to_date('24-APR-16','DD-MON-RR'),25,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (98,'Amber','Rose','amber.rose@example.com','650.507.9822',to_date('23-MAY-16','DD-MON-RR'),25,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (99,'Bella','Stone','bella.stone@example.com','650.507.9833',to_date('21-JUN-16','DD-MON-RR'),25,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (100,'Thea','Hawkins','thea.hawkins@example.com','650.507.9844',to_date('13-JAN-16','DD-MON-RR'),25,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (81,'Lola','Ramos','lola.ramos@example.com','650.507.9876',to_date('24-JAN-16','DD-MON-RR'),21,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (82,'Willow','Reyes','willow.reyes@example.com','650.507.9877',to_date('23-FEB-16','DD-MON-RR'),21,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (83,'Ivy','Burns','ivy.burns@example.com','650.507.9878',to_date('21-JUN-16','DD-MON-RR'),21,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (84,'Erin','Gordon','erin.gordon@example.com','650.507.9879',to_date('03-FEB-16','DD-MON-RR'),21,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (33,'Reggie','Simmons','reggie.simmons@example.com','650.124.8234',to_date('10-APR-16','DD-MON-RR'),22,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (44,'Emily','Hamilton','emily.hamilton@example.com','650.121.2874',to_date('15-MAR-16','DD-MON-RR'),25,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (43,'Olivia','Ford','olivia.ford@example.com','650.121.2994',to_date('29-JAN-16','DD-MON-RR'),25,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (42,'Amelia','Myers','amelia.myers@example.com','650.121.8009',to_date('17-OCT-16','DD-MON-RR'),25,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (41,'Connor','Hayes','connor.hayes@example.com','650.121.1834',to_date('06-APR-16','DD-MON-RR'),24,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (26,'Leon','Powell','leon.powell@example.com','650.124.1214',to_date('16-JUL-16','DD-MON-RR'),21,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (27,'Kai','Long','kai.long@example.com','650.124.1224',to_date('28-SEP-16','DD-MON-RR'),21,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (28,'Aaron','Patterson','aaron.patterson@example.com','650.124.1334',to_date('14-JAN-16','DD-MON-RR'),21,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (29,'Roman','Hughes','roman.hughes@example.com','650.124.1434',to_date('08-MAR-16','DD-MON-RR'),21,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (30,'Austin','Flores','austin.flores@example.com','650.124.5234',to_date('20-AUG-16','DD-MON-RR'),22,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (31,'Ellis','Washington','ellis.washington@example.com','650.124.6234',to_date('30-OCT-16','DD-MON-RR'),22,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (32,'Jamie','Butler','jamie.butler@example.com','650.124.7234',to_date('16-FEB-16','DD-MON-RR'),22,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (45,'Isla','Graham','isla.graham@example.com','650.121.2004',to_date('09-JUL-16','DD-MON-RR'),25,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (34,'Seth','Foster','seth.foster@example.com','650.127.1934',to_date('14-JUN-16','DD-MON-RR'),23,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (35,'Carter','Gonzales','carter.gonzales@example.com','650.127.1834',to_date('26-AUG-16','DD-MON-RR'),23,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (36,'Felix','Bryant','felix.bryant@example.com','650.127.1734',to_date('12-DEC-16','DD-MON-RR'),23,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (37,'Ibrahim','Alexander','ibrahim.alexander@example.com','650.127.1634',to_date('06-FEB-16','DD-MON-RR'),23,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (38,'Sonny','Russell','sonny.russell@example.com','650.121.1234',to_date('14-JUL-16','DD-MON-RR'),24,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (39,'Kian','Griffin','kian.griffin@example.com','650.121.2034',to_date('26-OCT-16','DD-MON-RR'),24,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (40,'Caleb','Diaz','caleb.diaz@example.com','650.121.2019',to_date('12-FEB-16','DD-MON-RR'),24,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (25,'Ronnie','Perry','ronnie.perry@example.com','650.123.5234',to_date('16-NOV-16','DD-MON-RR'),1,'Stock Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (24,'Callum','Jenkins','callum.jenkins@example.com','650.123.4234',to_date('10-OCT-16','DD-MON-RR'),1,'Stock Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (23,'Jackson','Coleman','jackson.coleman@example.com','650.123.3234',to_date('01-MAY-16','DD-MON-RR'),1,'Stock Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (22,'Liam','Henderson','liam.henderson@example.com','650.123.2234',to_date('10-APR-16','DD-MON-RR'),1,'Stock Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (21,'Jaxon','Ross','jaxon.ross@example.com','650.123.1234',to_date('18-JUL-16','DD-MON-RR'),1,'Stock Manager');
如果您对员工 ID 没有任何条件，您最终会得到发生自我匹配的记录，例如结果将显示“Gracie Gardner 与 Gracie Gardner 在同一天被聘用”
然后我们可以输入 ON e1.employee_id <> e2.employee_id - 这会阻止 Gracie 与 Gracie 匹配，但是您会发现“Gracie Gardner 与 Summer Payne 在同一天被雇用”和“Summer Payne 被雇用于与 Gracie Gardner 同一天”——也就是说，你会在“人与人配对”方面得到“重复记录”，每个名字都被双向提及
使用大于可以防止这种情况发生，并且实际上意味着任何给定的一对名称只出现一次。因为 Gracie 的 ID 小于 Summer，所以你会得到 Gracie in e1 和 Summer in e2 的配对，但你不会得到 Summer in e1 和 Gracie in e2
的配对
另一种可视化方式是使用 square/matrix
no id id1<>id2 id1<id2
A B C A B C A B C
A * * * A * * A
B * * * B * * B *
C * * * C * * C * *
在第一个方块中，所有东西都匹配。在第二个中，你删除了 AA / BB / CC 匹配项，但你仍然有 AB 和 BA、AC 和 CA 等。在第三个方块中，你只有唯一配对的字母（AB 但不是 BA，AC 但不是 CA，...）
如果您比较 !=（而不是 >）：
SELECT e1.hire_date,
e1.first_name || ' ' || e1.last_name AS employee1,
e2.first_name || ' ' || e2.last_name AS employee2
FROM employees e1
INNER JOIN employees e2
ON e1.employee_id != e2.employee_id AND e1.hire_date = e2.hire_date
ORDER BY
e1.hire_date DESC,
employee1,
employee2;
然后你会发现你得到了重复的行，其中的值的名称被调换了：
HIRE_DATE
EMPLOYEE1
EMPLOYEE2
07-DEC-16
Elliot Brooks
Rory Kelly
07-DEC-16
Rory Kelly
Elliot Brooks
如果您只使用 > 那么您只会得到两行中的其中一行，因为另一行被过滤掉了：
HIRE_DATE
EMPLOYEE1
EMPLOYEE2
07-DEC-16
Rory Kelly
Elliot Brooks
db<>fiddle here
我正在处理一些自连接示例，但我在下面的示例中画了一个空白。下面是最后一个例子 link Self-Join Example
SELECT
e1.hire_date,
(e1.first_name || ' ' || e1.last_name) employee1,
(e2.first_name || ' ' || e2.last_name) employee2
FROM
employees e1
INNER JOIN employees e2 ON
e1.employee_id > e2.employee_id
AND e1.hire_date = e2.hire_date
ORDER BY
e1.hire_date DESC,
employee1,
employee2;
我不明白为什么我需要检查第一个员工实例的 Employee_id 是否大于第二个员工实例的 employee_id。
如果有人能对此提供一个很好的解释，将不胜感激。
需要 create/insert 个脚本。
CREATE TABLE employees
(
employee_id NUMBER
GENERATED BY DEFAULT AS IDENTITY START WITH 108
PRIMARY KEY,
first_name VARCHAR( 255 ) NOT NULL,
last_name VARCHAR( 255 ) NOT NULL,
email VARCHAR( 255 ) NOT NULL,
phone VARCHAR( 50 ) NOT NULL ,
hire_date DATE NOT NULL ,
manager_id NUMBER( 12, 0 ) , -- fk
job_title VARCHAR( 255 ) NOT NULL,
CONSTRAINT fk_employees_manager
FOREIGN KEY( manager_id )
REFERENCES employees( employee_id )
ON DELETE CASCADE
);
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (107,'Summer','Payne','summer.payne@example.com','515.123.8181',to_date('07-JUN-16','DD-MON-RR'),106,'Public Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (106,'Rose','Stephens','rose.stephens@example.com','515.123.8080',to_date('07-JUN-16','DD-MON-RR'),2,'Accounting Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (101,'Annabelle','Dunn','annabelle.dunn@example.com','515.123.4444',to_date('17-SEP-16','DD-MON-RR'),2,'Administration Assistant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (1,'Tommy','Bailey','tommy.bailey@example.com','515.123.4567',to_date('17-JUN-16','DD-MON-RR'),null,'President');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (3,'Blake','Cooper','blake.cooper@example.com','515.123.4569',to_date('13-JAN-16','DD-MON-RR'),1,'Administration Vice President');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (2,'Jude','Rivera','jude.rivera@example.com','515.123.4568',to_date('21-SEP-16','DD-MON-RR'),1,'Administration Vice President');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (11,'Tyler','Ramirez','tyler.ramirez@example.com','515.124.4269',to_date('28-SEP-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (10,'Ryan','Gray','ryan.gray@example.com','515.124.4169',to_date('16-AUG-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (14,'Elliot','Brooks','ellibrooks@example.com','515.124.4567',to_date('07-DEC-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (12,'Elliott','James','elliott.james@example.com','515.124.4369',to_date('30-SEP-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (13,'Albert','Watson','albert.watson@example.com','515.124.4469',to_date('07-MAR-16','DD-MON-RR'),9,'Accountant');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (9,'Mohammad','Peterson','mohammad.peterson@example.com','515.124.4569',to_date('17-AUG-16','DD-MON-RR'),2,'Finance Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (104,'Harper','Spencer','harper.spencer@example.com','515.123.7777',to_date('07-JUN-16','DD-MON-RR'),2,'Human Resources Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (4,'Louie','Richardson','louie.richardson@example.com','590.423.4567',to_date('03-JAN-16','DD-MON-RR'),3,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (5,'Nathan','Cox','nathan.cox@example.com','590.423.4568',to_date('21-MAY-16','DD-MON-RR'),4,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (8,'Bobby','Torres','bobby.torres@example.com','590.423.5567',to_date('07-FEB-16','DD-MON-RR'),4,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (7,'Charles','Ward','charles.ward@example.com','590.423.4560',to_date('05-FEB-16','DD-MON-RR'),4,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (6,'Gabriel','Howard','gabriel.howard@example.com','590.423.4569',to_date('25-JUN-16','DD-MON-RR'),4,'Programmer');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (102,'Emma','Perkins','emma.perkins@example.com','515.123.5555',to_date('17-FEB-16','DD-MON-RR'),1,'Marketing Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (103,'Amelie','Hudson','amelie.hudson@example.com','603.123.6666',to_date('17-AUG-16','DD-MON-RR'),102,'Marketing Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (105,'Gracie','Gardner','gracie.gardner@example.com','515.123.8888',to_date('07-JUN-16','DD-MON-RR'),2,'Public Relations Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (17,'Frederick','Price','frederick.price@example.com','515.127.4563',to_date('24-DEC-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (16,'Alex','Sanders','alex.sanders@example.com','515.127.4562',to_date('18-MAY-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (18,'Ollie','Bennett','ollie.bennett@example.com','515.127.4564',to_date('24-JUL-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (19,'Louis','Wood','louis.wood@example.com','515.127.4565',to_date('15-NOV-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (20,'Dexter','Barnes','dexter.barnes@example.com','515.127.4566',to_date('10-AUG-16','DD-MON-RR'),15,'Purchasing Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (15,'Rory','Kelly','rory.kelly@example.com','515.127.4561',to_date('07-DEC-16','DD-MON-RR'),1,'Purchasing Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (49,'Isabella','Cole','isabella.cole@example.com','011.44.1344.619268',to_date('15-OCT-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (48,'Jessica','Woods','jessica.woods@example.com','011.44.1344.429278',to_date('10-MAR-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (47,'Ella','Wallace','ella.wallace@example.com','011.44.1344.467268',to_date('05-JAN-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (46,'Ava','Sullivan','ava.sullivan@example.com','011.44.1344.429268',to_date('01-OCT-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (50,'Mia','West','mia.west@example.com','011.44.1344.429018',to_date('29-JAN-16','DD-MON-RR'),1,'Sales Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (56,'Evie','Harrison','evie.harrison@example.com','011.44.1344.486508',to_date('23-NOV-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (57,'Scarlett','Gibson','scarlett.gibson@example.com','011.44.1345.429268',to_date('30-JAN-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (58,'Ruby','Mcdonald','ruby.mcdonald@example.com','011.44.1345.929268',to_date('04-MAR-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (59,'Chloe','Cruz','chloe.cruz@example.com','011.44.1345.829268',to_date('01-AUG-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (60,'Isabelle','Marshall','isabelle.marshall@example.com','011.44.1345.729268',to_date('10-MAR-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (61,'Daisy','Ortiz','daisy.ortiz@example.com','011.44.1345.629268',to_date('15-DEC-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (62,'Freya','Gomez','freya.gomez@example.com','011.44.1345.529268',to_date('03-NOV-16','DD-MON-RR'),47,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (80,'Elizabeth','Dixon','elizabeth.dixon@example.com','011.44.1644.429262',to_date('04-JAN-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (64,'Florence','Freeman','florence.freeman@example.com','011.44.1346.229268',to_date('19-MAR-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (65,'Alice','Wells','alice.wells@example.com','011.44.1346.329268',to_date('24-JAN-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (66,'Charlotte','Webb','charlotte.webb@example.com','011.44.1346.529268',to_date('23-FEB-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (67,'Sienna','Simpson','sienna.simpson@example.com','011.44.1346.629268',to_date('24-MAR-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (68,'Matilda','Stevens','matilda.stevens@example.com','011.44.1346.729268',to_date('21-APR-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (69,'Evelyn','Tucker','evelyn.tucker@example.com','011.44.1343.929268',to_date('11-MAR-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (70,'Eva','Porter','eva.porter@example.com','011.44.1343.829268',to_date('23-MAR-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (71,'Millie','Hunter','millie.hunter@example.com','011.44.1343.729268',to_date('24-JAN-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (72,'Sofia','Hicks','sofia.hicks@example.com','011.44.1343.629268',to_date('23-FEB-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (73,'Lucy','Crawford','lucy.crawford@example.com','011.44.1343.529268',to_date('24-MAR-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (74,'Elsie','Henry','elsie.henry@example.com','011.44.1343.329268',to_date('21-APR-16','DD-MON-RR'),49,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (75,'Imogen','Boyd','imogen.boyd@example.com','011.44.1644.429267',to_date('11-MAY-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (76,'Layla','Mason','layla.mason@example.com','011.44.1644.429266',to_date('19-MAR-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (77,'Rosie','Morales','rosie.morales@example.com','011.44.1644.429265',to_date('24-MAR-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (78,'Maya','Kennedy','maya.kennedy@example.com','011.44.1644.429264',to_date('23-APR-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (79,'Esme','Warren','esme.warren@example.com','011.44.1644.429263',to_date('24-MAY-16','DD-MON-RR'),50,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (55,'Grace','Ellis','grace.ellis@example.com','011.44.1344.987668',to_date('09-DEC-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (54,'Lily','Fisher','lily.fisher@example.com','011.44.1344.498718',to_date('30-MAR-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (53,'Sophia','Reynolds','sophia.reynolds@example.com','011.44.1344.478968',to_date('20-AUG-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (52,'Sophie','Owens','sophie.owens@example.com','011.44.1344.345268',to_date('24-MAR-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (51,'Poppy','Jordan','poppy.jordan@example.com','011.44.1344.129268',to_date('30-JAN-16','DD-MON-RR'),46,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (63,'Phoebe','Murray','phoebe.murray@example.com','011.44.1346.129268',to_date('11-NOV-16','DD-MON-RR'),48,'Sales Representative');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (85,'Holly','Shaw','holly.shaw@example.com','650.509.1876',to_date('27-JAN-16','DD-MON-RR'),22,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (86,'Emilia','Holmes','emilia.holmes@example.com','650.509.2876',to_date('20-FEB-16','DD-MON-RR'),22,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (87,'Molly','Rice','molly.rice@example.com','650.509.3876',to_date('24-JUN-16','DD-MON-RR'),22,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (88,'Ellie','Robertson','ellie.robertson@example.com','650.509.4876',to_date('07-FEB-16','DD-MON-RR'),22,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (89,'Jasmine','Hunt','jasmine.hunt@example.com','650.505.1876',to_date('14-JUN-16','DD-MON-RR'),23,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (90,'Eliza','Black','eliza.black@example.com','650.505.2876',to_date('13-AUG-16','DD-MON-RR'),23,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (91,'Lilly','Daniels','lilly.daniels@example.com','650.505.3876',to_date('11-JUL-16','DD-MON-RR'),23,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (92,'Abigail','Palmer','abigail.palmer@example.com','650.505.4876',to_date('19-DEC-16','DD-MON-RR'),23,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (93,'Georgia','Mills','georgia.mills@example.com','650.501.1876',to_date('04-FEB-16','DD-MON-RR'),24,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (94,'Maisie','Nichols','maisie.nichols@example.com','650.501.2876',to_date('03-MAR-16','DD-MON-RR'),24,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (95,'Eleanor','Grant','eleanor.grant@example.com','650.501.3876',to_date('01-JUL-16','DD-MON-RR'),24,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (96,'Hannah','Knight','hannah.knight@example.com','650.501.4876',to_date('17-MAR-16','DD-MON-RR'),24,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (97,'Harriet','Ferguson','harriet.ferguson@example.com','650.507.9811',to_date('24-APR-16','DD-MON-RR'),25,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (98,'Amber','Rose','amber.rose@example.com','650.507.9822',to_date('23-MAY-16','DD-MON-RR'),25,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (99,'Bella','Stone','bella.stone@example.com','650.507.9833',to_date('21-JUN-16','DD-MON-RR'),25,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (100,'Thea','Hawkins','thea.hawkins@example.com','650.507.9844',to_date('13-JAN-16','DD-MON-RR'),25,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (81,'Lola','Ramos','lola.ramos@example.com','650.507.9876',to_date('24-JAN-16','DD-MON-RR'),21,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (82,'Willow','Reyes','willow.reyes@example.com','650.507.9877',to_date('23-FEB-16','DD-MON-RR'),21,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (83,'Ivy','Burns','ivy.burns@example.com','650.507.9878',to_date('21-JUN-16','DD-MON-RR'),21,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (84,'Erin','Gordon','erin.gordon@example.com','650.507.9879',to_date('03-FEB-16','DD-MON-RR'),21,'Shipping Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (33,'Reggie','Simmons','reggie.simmons@example.com','650.124.8234',to_date('10-APR-16','DD-MON-RR'),22,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (44,'Emily','Hamilton','emily.hamilton@example.com','650.121.2874',to_date('15-MAR-16','DD-MON-RR'),25,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (43,'Olivia','Ford','olivia.ford@example.com','650.121.2994',to_date('29-JAN-16','DD-MON-RR'),25,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (42,'Amelia','Myers','amelia.myers@example.com','650.121.8009',to_date('17-OCT-16','DD-MON-RR'),25,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (41,'Connor','Hayes','connor.hayes@example.com','650.121.1834',to_date('06-APR-16','DD-MON-RR'),24,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (26,'Leon','Powell','leon.powell@example.com','650.124.1214',to_date('16-JUL-16','DD-MON-RR'),21,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (27,'Kai','Long','kai.long@example.com','650.124.1224',to_date('28-SEP-16','DD-MON-RR'),21,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (28,'Aaron','Patterson','aaron.patterson@example.com','650.124.1334',to_date('14-JAN-16','DD-MON-RR'),21,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (29,'Roman','Hughes','roman.hughes@example.com','650.124.1434',to_date('08-MAR-16','DD-MON-RR'),21,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (30,'Austin','Flores','austin.flores@example.com','650.124.5234',to_date('20-AUG-16','DD-MON-RR'),22,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (31,'Ellis','Washington','ellis.washington@example.com','650.124.6234',to_date('30-OCT-16','DD-MON-RR'),22,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (32,'Jamie','Butler','jamie.butler@example.com','650.124.7234',to_date('16-FEB-16','DD-MON-RR'),22,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (45,'Isla','Graham','isla.graham@example.com','650.121.2004',to_date('09-JUL-16','DD-MON-RR'),25,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (34,'Seth','Foster','seth.foster@example.com','650.127.1934',to_date('14-JUN-16','DD-MON-RR'),23,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (35,'Carter','Gonzales','carter.gonzales@example.com','650.127.1834',to_date('26-AUG-16','DD-MON-RR'),23,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (36,'Felix','Bryant','felix.bryant@example.com','650.127.1734',to_date('12-DEC-16','DD-MON-RR'),23,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (37,'Ibrahim','Alexander','ibrahim.alexander@example.com','650.127.1634',to_date('06-FEB-16','DD-MON-RR'),23,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (38,'Sonny','Russell','sonny.russell@example.com','650.121.1234',to_date('14-JUL-16','DD-MON-RR'),24,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (39,'Kian','Griffin','kian.griffin@example.com','650.121.2034',to_date('26-OCT-16','DD-MON-RR'),24,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (40,'Caleb','Diaz','caleb.diaz@example.com','650.121.2019',to_date('12-FEB-16','DD-MON-RR'),24,'Stock Clerk');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (25,'Ronnie','Perry','ronnie.perry@example.com','650.123.5234',to_date('16-NOV-16','DD-MON-RR'),1,'Stock Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (24,'Callum','Jenkins','callum.jenkins@example.com','650.123.4234',to_date('10-OCT-16','DD-MON-RR'),1,'Stock Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (23,'Jackson','Coleman','jackson.coleman@example.com','650.123.3234',to_date('01-MAY-16','DD-MON-RR'),1,'Stock Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (22,'Liam','Henderson','liam.henderson@example.com','650.123.2234',to_date('10-APR-16','DD-MON-RR'),1,'Stock Manager');
Insert into EMPLOYEES (EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE,HIRE_DATE,MANAGER_ID,JOB_TITLE) values (21,'Jaxon','Ross','jaxon.ross@example.com','650.123.1234',to_date('18-JUL-16','DD-MON-RR'),1,'Stock Manager');
如果您对员工 ID 没有任何条件，您最终会得到发生自我匹配的记录，例如结果将显示“Gracie Gardner 与 Gracie Gardner 在同一天被聘用”
然后我们可以输入 ON e1.employee_id <> e2.employee_id - 这会阻止 Gracie 与 Gracie 匹配，但是您会发现“Gracie Gardner 与 Summer Payne 在同一天被雇用”和“Summer Payne 被雇用于与 Gracie Gardner 同一天”——也就是说，你会在“人与人配对”方面得到“重复记录”，每个名字都被双向提及
使用大于可以防止这种情况发生，并且实际上意味着任何给定的一对名称只出现一次。因为 Gracie 的 ID 小于 Summer，所以你会得到 Gracie in e1 和 Summer in e2 的配对，但你不会得到 Summer in e1 和 Gracie in e2
另一种可视化方式是使用 square/matrix
no id id1<>id2 id1<id2
A B C A B C A B C
A * * * A * * A
B * * * B * * B *
C * * * C * * C * *
在第一个方块中，所有东西都匹配。在第二个中，你删除了 AA / BB / CC 匹配项，但你仍然有 AB 和 BA、AC 和 CA 等。在第三个方块中，你只有唯一配对的字母（AB 但不是 BA，AC 但不是 CA，...）
如果您比较 !=（而不是 >）：
SELECT e1.hire_date,
e1.first_name || ' ' || e1.last_name AS employee1,
e2.first_name || ' ' || e2.last_name AS employee2
FROM employees e1
INNER JOIN employees e2
ON e1.employee_id != e2.employee_id AND e1.hire_date = e2.hire_date
ORDER BY
e1.hire_date DESC,
employee1,
employee2;
然后你会发现你得到了重复的行，其中的值的名称被调换了：
HIRE_DATE EMPLOYEE1 EMPLOYEE2 07-DEC-16 Elliot Brooks Rory Kelly 07-DEC-16 Rory Kelly Elliot Brooks
如果您只使用 > 那么您只会得到两行中的其中一行，因为另一行被过滤掉了：
HIRE_DATE EMPLOYEE1 EMPLOYEE2 07-DEC-16 Rory Kelly Elliot Brooks
db<>fiddle here