How do I include certain conditions in SQL Count

Question

`CREATE TABLE PERSON
(
  Person_id      NUMBER(3) PRIMARY KEY,
  Surname        VARCHAR2(20),
  First_name     VARCHAR2(20),
  Sex            CHAR(1),
  Birth_date     DATE,
  Street         VARCHAR2(40),
  Town           CHAR(20),
  Postcode       NUMBER(4),
  Next_of_kin    NUMBER(3)
 );
CREATE TABLE STAFF
(
  Person_id     NUMBER(3) PRIMARY KEY,
  Start_date    DATE,
  Staff_type    VARCHAR2(15),
  Charges       NUMBER(10,2),
  Resign_date   DATE,
  FOREIGN KEY (Person_id) references PERSON(Person_id)
  );
CREATE TABLE WARD (
   Ward_code         CHAR(3) PRIMARY KEY,
   Ward_name         VARCHAR2(20),
   Bed_count         NUMBER(4),
   Opened_date       DATE,
   Last_painted_date DATE,
   Daily_charge      NUMBER(10,2)
);
CREATE TABLE OPERATION_TYPE (
   Op_code         CHAR(3) PRIMARY KEY,
   Operation_name  VARCHAR2(50),
   Theatre_fee     NUMBER(10,2),
   Days_in         NUMBER(5)
);
CREATE TABLE ADMISSION (
   Admission_id    NUMBER(3) PRIMARY KEY,
   Patient_id      NUMBER(3),
   Admission_date  DATE NOT NULL,
   Expected_op     CHAR(3),
   Admitted_by     NUMBER(3),
   Ward_code       CHAR(3),
   Discharge_date  DATE,
FOREIGN KEY (Patient_id) references PERSON(Person_id),
FOREIGN KEY (Expected_op) references OPERATION_TYPE(Op_code),
FOREIGN KEY (Admitted_by) references PERSON(Person_id),
FOREIGN KEY (Ward_code) references WARD(Ward_code)
);
CREATE TABLE OPERATION (
   Operation_id     NUMBER(3) PRIMARY KEY,
   Actual_op        CHAR(3),
   Admission_id     NUMBER(3),
   Op_date          DATE,
   Surgeon          NUMBER(3),
   Anaesthetist     NUMBER(3),
FOREIGN KEY (Surgeon) references PERSON(Person_id),
FOREIGN KEY (Anaesthetist) references PERSON(Person_id),
FOREIGN KEY (Actual_op) references OPERATION_TYPE(Op_code),
FOREIGN KEY (Admission_id) references ADMISSION(Admission_id)
);
CREATE TABLE OBSERVATION(
   Admission_id  NUMBER(3),
   Observ_date   DATE,
   Observ_time   NUMBER(4),
   Observ_type   CHAR(10),
   Observ_value  NUMBER(4),
   Staff_id      NUMBER(3),
PRIMARY KEY (Admission_id,Observ_date,Observ_time,Observ_type),
FOREIGN KEY (Admission_id) references ADMISSION(Admission_id),
FOREIGN KEY (Staff_id) references STAFF(Person_id)
);
REM***********************
REM  PERSON TABLE
REM***********************
INSERT INTO PERSON VALUES (101,'Black','Barry','M','31/12/1959','11 High St.','Cooma',2630,102);
INSERT INTO PERSON VALUES (102,'Black','Mary','F','11/04/1965','11 High St.','Cooma',2630,NULL);
INSERT INTO PERSON VALUES (103,'Strathclyde','Albert','M','15/5/1955','3 The Mews','Hawthorne',3171,104);
INSERT INTO PERSON VALUES (104,'Strathclyde','Alice','F','17/7/1955','3 The Mews','Hawthorne',3171,103);
INSERT INTO PERSON VALUES (105,'Green','Gill','F','16/6/1966','124 Main St.','Young',2594,106);
INSERT INTO PERSON VALUES (106,'Green','Graham','M','24/4/1967','124 Main St.','Young',2594,105);
INSERT INTO PERSON VALUES (107,'Gray','Lesley','F','12/9/1972','130 Main St.','Young',2594,109);
INSERT INTO PERSON VALUES (109,'Gray','John','M','14/4/1972','130 Main St.','Young',2594,107);
INSERT INTO PERSON VALUES (110,'Samuelson','Thomas','M','1/1/1964','17 The Mews','Hawthorne',3171,NULL);
INSERT INTO PERSON VALUES (111,'Abrahams','Mary','F','15/5/1967','2177A The Esplanade','Ivanhoe',3878,NULL);
INSERT INTO PERSON VALUES (112,'Aumann','Monica','F','25/5/1955','29 The Esplanade','Ivanhoe',3878,NULL);
INSERT INTO PERSON VALUES (113,'Brown','Melissa','F','8/8/1984','11 East St.','Cooma',2630,NULL);
INSERT INTO PERSON VALUES (114,'Napier','Mary','F','1/1/1971','163 New Rd.','Henty',2658,NULL);
INSERT INTO PERSON VALUES (115,'Nelson','Nigel','M','2/2/1972','165 Young Rd.','Temora',2666,NULL);
INSERT INTO PERSON VALUES (116,'Newman','Olive','F','3/3/1973','21 Olympic Way','Henty',2658,NULL);
INSERT INTO PERSON VALUES (117,'Gray','Lesley','M','31/12/1989','130 Andres St.','Young',2594,105);
INSERT INTO PERSON VALUES (118,'Hon','Tasuku','M','13/3/1953','21 Silcon Height','Henty',2658,NULL);
INSERT INTO PERSON VALUES (119,'Livingstone','Frank','M','3/3/2003','21 Sun Height','Henty',2658,122);
INSERT INTO PERSON VALUES (120,'Giggle','Frank','M','23/3/1975','21 Albrige Close','Cooma',2630,121);
INSERT INTO PERSON VALUES (121,'Giggle','Felicia','F','3/3/1980','21 Albrige Close','Cooma',2630,120);
INSERT INTO PERSON VALUES (122,'Black','Frank Jr','M','13/3/2011','21 Stun Height','Henty',2658,123);
INSERT INTO PERSON VALUES (123,'Black','Frances','F','12/12/2005','21 Stun Height','Henty',2658,122);
INSERT INTO PERSON VALUES (124,'Smith','Buddy','M','11/12/1979','101 High St.','Cooma',2630,NULL);
INSERT INTO PERSON VALUES (125,'Smith','Maxime','F','31/12/1979','101 High St.','Cooma',2630,124);
INSERT INTO PERSON VALUES (126,'Smith','Issac','M','1/12/2007','101 High St.','Cooma',2630,124);
INSERT INTO PERSON VALUES (127,'Smith','Ronny','M','3/12/2009','101 High St.','Cooma',2630,124);
INSERT INTO PERSON VALUES (128,'Giggle','Fanny','F','3/12/2007','121 Close Rose','Hillo',2330,120);
INSERT INTO PERSON VALUES (129,'Murad','Nadia','F','3/3/2000','121 Close Rose', 'Hillo',2330,130);
INSERT INTO PERSON VALUES (130,'Murad','Tange','M','3/3/1999','7711 Albrige Close','Cooma',2630,NULL);
INSERT INTO PERSON VALUES (131,'Rome','Paula','F','23/9/1965','21 Height Close','Cooma',2630,132);
INSERT INTO PERSON VALUES (132,'Rome','Paul','M','13/3/1966','21 Height Close','Cooma',2630,NULL);
INSERT INTO PERSON VALUES (133,'Rome','Fay','M','3/3/2017','21 Height Close','Cooma',2630,132);
INSERT INTO PERSON VALUES (134,'Murad','Michelle','F','3/3/2001','1 Height Close','Cooma',2630,NULL);
INSERT INTO PERSON VALUES (135,'Trump','Donald','M','13/3/1956','222 White House Avenue','Cooma',2630,NULL);
INSERT INTO PERSON VALUES (136,'Trump','Melania','F','3/3/1992','222 White House Avenue','Cooma',2630,135);
INSERT INTO PERSON VALUES (137,'Trump','Baron','M','3/6/2005','222 White House Avenue','Cooma',2630,135);
INSERT INTO PERSON VALUES (138,'Johnson','Boris','M','23/9/1965','10 Downing Street','Wagga Wagga',2999,NULL);
INSERT INTO PERSON VALUES (139,'Cordeiro','Wayne','M','3/3/1965','777 Hawaii Close Rose', 'Hillo',7770, NULL);
INSERT INTO PERSON VALUES (140,'Cordeiro','Anne','F','23/4/1968','777 Hawaii Close Rose', 'Hillo',7770, 139);
INSERT INTO PERSON VALUES (141,'Thatcher','Margaret','F','21/1/1955','120 Main Sq.','Wagga Wagga',2999,142);
INSERT INTO PERSON VALUES (142,'Thatcher','Denis','M','23/9/1955','120 Main Sq.','Wagga Wagga',2999,NULL);
INSERT INTO PERSON VALUES (143,'Thatcher','Carols','F','1/9/1985','120 Main Sq.','Wagga Wagga',2999,142);
INSERT INTO PERSON VALUES (144,'Nelson','Nigel','M','22/2/1992','15 Young Rd.','Temora',2666,NULL);
INSERT INTO PERSON VALUES (145,'Neon','Gela','F','2/2/1972','1465 Main Rd.','Temora',2666,NULL);
INSERT INTO PERSON VALUES (146,'Twain','Shane','F','21/1/1995','A-129 Main Rose Sq.','Wagga Wagga',2650,147);
INSERT INTO PERSON VALUES (147,'Twain','Dens','M','23/9/1985','A-129 Main Rose Sq.','Wagga Wagga',2650,NULL);
INSERT INTO PERSON VALUES (148,'Trump','Ivanka','F','5/3/1985','222 White House Avenue','Cooma',2630,135);
INSERT INTO PERSON VALUES (149,'Trump','Eric','M','3/12/1975','222 White House Avenue','Cooma',2630,135);
INSERT INTO PERSON VALUES (150,'Gates','Bill','M','5/3/1975','2 Rosey Lane','Cooma',2630,NULL);
INSERT INTO PERSON VALUES (151,'Bucket','Eric','M','3/1/1985','11 Oserey Avenue','Cooma',2630,NULL);

REM*******************************************************
REM STAFF TABLE
REM nursing services will not be charged to the patients
REM*******************************************************
INSERT INTO STAFF VALUES (103,'1/1/2009','Surgeon',4525,NULL);
INSERT INTO STAFF VALUES (110,'5/5/2009','Surgeon',5600,NULL);
INSERT INTO STAFF VALUES (118,'1/5/2016','Surgeon',7890,NULL);
INSERT INTO STAFF VALUES (111,'1/1/2009','Anaesthetist',5900,NULL);
INSERT INTO STAFF VALUES (112,'3/3/2009','Anaesthetist',4788,NULL);
INSERT INTO STAFF VALUES (114,'1/1/2009','Senior Nurse',NULL,NULL);
INSERT INTO STAFF VALUES (115,'2/2/2016','Nurse',NULL,NULL);
INSERT INTO STAFF VALUES (116,'3/3/2014','Nurse',NULL,NULL);
INSERT INTO STAFF VALUES (125,'23/3/2014','Nurse',NULL,NULL);
INSERT INTO STAFF VALUES (135,'1/1/2019','Senior Nurse',NULL,NULL);
INSERT INTO STAFF VALUES (136,'2/2/2016','Nurse',NULL,NULL);
INSERT INTO STAFF VALUES (138,'23/3/2019','Nurse',NULL,NULL);
INSERT INTO STAFF VALUES (139,'23/3/2020','Senior Nurse',NULL,NULL);
INSERT INTO STAFF VALUES (150,'1/11/2019','Anaesthetist',6900,NULL);
INSERT INTO STAFF VALUES (151,'31/1/2019','Anaesthetist',5900,NULL);

REM***********************
REM  WARD TABLE
REM***********************
INSERT INTO WARD VALUES ('C','Covid Bay',90,'31/12/2019',NULL,150.00);
INSERT INTO WARD VALUES ('A','Abraham',80,'1/12/2015','12/05/2011',350.00);
INSERT INTO WARD VALUES ('N','Nightingale',50,'1/12/2017','12/05/2012',450.00);
INSERT INTO WARD VALUES ('F','Flemming',75,'15/11/2009',NULL,230.00);
INSERT INTO WARD VALUES ('L','Lister',80,'1/1/2009','20/12/2013',200.00);
INSERT INTO WARD VALUES ('P','Pasteur',60,'1/12/2009','12/12/2011',250.00);


REM***********************
REM  OPERATION_TYPE TABLE
REM***********************
INSERT INTO OPERATION_TYPE VALUES ('LO','Lobotomy',700.00,10);
INSERT INTO OPERATION_TYPE VALUES ('CS','Caesarean',5700.00,3);
INSERT INTO OPERATION_TYPE VALUES ('CT','Cataract',670.00,1);
INSERT INTO OPERATION_TYPE VALUES ('AP','Appendicectomy',500.00,5);
INSERT INTO OPERATION_TYPE VALUES ('HB','Heart Bypass',2000.00,14);
INSERT INTO OPERATION_TYPE VALUES ('HT','Heart Transplant',5000.00,30);
INSERT INTO OPERATION_TYPE VALUES ('HY','Hysterectomy',800.00,7);
INSERT INTO OPERATION_TYPE VALUES ('LA','Leg Amputation',1500.00,10);
INSERT INTO OPERATION_TYPE VALUES ('TS','Tonsillectomy',700.00,7);
INSERT INTO OPERATION_TYPE VALUES ('LP','Laparoscopy',500.00,1);
INSERT INTO OPERATION_TYPE VALUES ('AR','Arthroscopy ',700.00,17);


REM***********************
REM  ADMISSION TABLE
REM***********************
INSERT INTO ADMISSION VALUES (205,101,'2/2/2011','HB',114,'P','21/2/2011');
INSERT INTO ADMISSION VALUES (275,101,'1/9/2010','HY',115,'L','1/11/2010');
INSERT INTO ADMISSION VALUES (286,101,'3/5/2016','AR',116,'A','3/7/2016');
INSERT INTO ADMISSION VALUES (303,101,'3/4/2018','LA',125,'F', '13/5/2018');
INSERT INTO ADMISSION VALUES (298,103,'23/1/2016','TS',114,'L','24/04/2016');
INSERT INTO ADMISSION VALUES (299,103,'23/3/2018','AP',114,'L','23/4/2018');
INSERT INTO ADMISSION VALUES (305,103,'23/4/2018','HT',125,'F','29/5/2018');
INSERT INTO ADMISSION VALUES (321,103,'13/8/2018','AR',125,'F', '23/10/2018');
INSERT INTO ADMISSION VALUES (283,105,'3/12/2015','AR',116,'A','5/12/2015');
INSERT INTO ADMISSION VALUES (278,105,'1/1/2011','HB',115,'P','30/1/2011');
INSERT INTO ADMISSION VALUES (307,105,'3/4/2018','TS',125,'F', '13/5/2018');
INSERT INTO ADMISSION VALUES (276,106,'24/8/2010','LA',114,'P','15/9/2010');
INSERT INTO ADMISSION VALUES (287,106,'3/5/2016','TS',114,'A','3/6/2016');
INSERT INTO ADMISSION VALUES (274,109,'1/9/2019','AP',114,'P','9/9/2019');
INSERT INTO ADMISSION VALUES (288,109,'23/5/2016','LO',114,'F','3/07/2016');
INSERT INTO ADMISSION VALUES (301,112,'13/4/2018','AP',125,'F','16/4/2018');
INSERT INTO ADMISSION VALUES (304,112,'23/4/2019','LO',114,'L','23/5/2019');
INSERT INTO ADMISSION VALUES (279,113,'3/9/2010','TS',115,'F','10/9/2010');
INSERT INTO ADMISSION VALUES (284,113,'3/12/2015','HY',116,'A','03/01/2016');
INSERT INTO ADMISSION VALUES (285,113,'3/5/2016','HT',116,'A','3/6/2016');
INSERT INTO ADMISSION VALUES (300,113,'23/4/2018','AR',114,'L','25/6/2018');
INSERT INTO ADMISSION VALUES (306,113,'13/8/2018','AP',125,'L', '13/9/2018');
INSERT INTO ADMISSION VALUES (277,114,'20/9/2010','AP',115,'P','30/9/2010');
INSERT INTO ADMISSION VALUES (289,115,'11/4/2016','LO',114,'L','3/6/2016');
INSERT INTO ADMISSION VALUES (290,115,'5/7/2016','TS',114,'L','3/09/2016');
INSERT INTO ADMISSION VALUES (308,115,'23/3/2018','AR',114,'L','25/3/2018');
INSERT INTO ADMISSION VALUES (280,117,'13/9/2010','AP',115,'F','25/9/2010');
INSERT INTO ADMISSION VALUES (281,117,'3/9/2014','HB',116,'A','21/9/2014');
INSERT INTO ADMISSION VALUES (282,117,'3/12/2015','LA',116,'A','14/12/2015');
INSERT INTO ADMISSION VALUES (309,126,'23/3/2018','TS',125,'L', '13/5/2018');
INSERT INTO ADMISSION VALUES (310,127,'13/5/2018','AP',125,'L', '28/5/2018');
INSERT INTO ADMISSION VALUES (311,124,'3/5/2018','LO',125,'A', '23/5/2018');
INSERT INTO ADMISSION VALUES (312,127,'21/6/2019','LO',125,'L','22/8/2019');
INSERT INTO ADMISSION VALUES (313,124,'22/6/2019','AP',125,'A','22/7/2019');
INSERT INTO ADMISSION VALUES (314,109,'21/6/2019','LO',125,'L','22/7/2019');
INSERT INTO ADMISSION VALUES (315,126,'12/6/2019','AP',125,'A','22/9/2019');
INSERT INTO ADMISSION VALUES (316,114,'22/7/2019','HB',125,'A','12/12/2019');
INSERT INTO ADMISSION VALUES (318,128,'3/5/2019','LA',116,'A','4/6/2019');
INSERT INTO ADMISSION VALUES (319,129,'23/3/2019','TS',125,'L', '13/4/2019');
INSERT INTO ADMISSION VALUES (320,130,'3/5/2019','LA',116,'F','4/6/2019');
INSERT INTO ADMISSION VALUES (328,119,'3/3/2019','TS',115,'N', '3/4/2019');
INSERT INTO ADMISSION VALUES (322,132,'3/5/2019','LA',116,'A','4/6/2019');
INSERT INTO ADMISSION VALUES (323,133,'23/3/2019','TS',125,'L', '13/4/2019');
INSERT INTO ADMISSION VALUES (324,131,'3/5/2018','LA',116,'F','4/5/2018');
INSERT INTO ADMISSION VALUES (325,118,'3/6/2019','TS',115,'P', '3/7/2019');
INSERT INTO ADMISSION VALUES (326,102,'3/5/2018','LA',116,'F','4/5/2018');
INSERT INTO ADMISSION VALUES (327,104,'3/6/2019','TS',115,'P', '3/7/2019');
INSERT INTO ADMISSION VALUES (339,107,'3/6/2019','TS',115,'P', '3/7/2019');
INSERT INTO ADMISSION VALUES (329,110,'3/6/2019','TS',115,'P', '3/7/2019');
INSERT INTO ADMISSION VALUES (330,111,'3/6/2019','TS',115,'P', '3/7/2019');
INSERT INTO ADMISSION VALUES (331,116,'3/6/2019','TS',115,'P', '3/7/2019');
INSERT INTO ADMISSION VALUES (332,121,'21/6/2019','TS',125,'L','22/7/2019');
INSERT INTO ADMISSION VALUES (333,123,'22/7/2019','AP',125,'A','22/9/2019');
INSERT INTO ADMISSION VALUES (334,134,'21/8/2019','AP',115,'L','22/12/2019');
INSERT INTO ADMISSION VALUES (335,128,'12/8/2020','AP',115,'A',NULL);
INSERT INTO ADMISSION VALUES (336,125,'22/7/2020','HB',115,'A',NULL);
INSERT INTO ADMISSION VALUES (337,120,'21/8/2020','AP',116,'L',NULL);
INSERT INTO ADMISSION VALUES (338,130,'22/7/2020','AP',125,'N',NULL);
INSERT INTO ADMISSION VALUES (340,131,'22/8/2020','AP',125,'N',NULL);
INSERT INTO ADMISSION VALUES (341,122,'22/8/2020','AP',125,'N',NULL);
INSERT INTO ADMISSION VALUES (490,139,'11/8/2020','AP',125,'F',NULL);
INSERT INTO ADMISSION VALUES (491,140,'7/9/2020','AP',138,'F',NULL);
 

REM***********************
REM  OPERATION TABLE
REM***********************
INSERT INTO OPERATION VALUES (317,'HB',205,'4/2/2011',110,111);
INSERT INTO OPERATION VALUES (355,'LA',276,'25/8/2010',103,111);
INSERT INTO OPERATION VALUES (363,'AP',276,'3/9/2010',103,111);
INSERT INTO OPERATION VALUES (360,'AP',277,'22/9/2010',103,111);
INSERT INTO OPERATION VALUES (361,'AP',274,'2/9/2010',103,111);
INSERT INTO OPERATION VALUES (362,'HT',275,'3/9/2010',110,112);
INSERT INTO OPERATION VALUES (364,'AP',279,'3/9/2010',103,111);
INSERT INTO OPERATION VALUES (365,'AP',280,'6/9/2010',103,111);
INSERT INTO OPERATION VALUES (366,'HB',281,'6/9/2014',103,111);
INSERT INTO OPERATION VALUES (367,'HY',284,'6/12/2015',103,111);
INSERT INTO OPERATION VALUES (368,'LO',285,'6/5/2016',118,112);
INSERT INTO OPERATION VALUES (369,'AP',286,'6/5/2016',118,112);
INSERT INTO OPERATION VALUES (370,'TS',287,'7/5/2016',118,112);
INSERT INTO OPERATION VALUES (371,'LA',288,'26/5/2016',110,111); 
INSERT INTO OPERATION VALUES (372,'LO',289,'16/4/2016',110,111);
INSERT INTO OPERATION VALUES (373,'TS',290,'6/5/2016',110,111);
INSERT INTO OPERATION VALUES (381,'TS',298,'26/2/2016',110,111);
INSERT INTO OPERATION VALUES (382,'AP',299,'26/3/2018',110,111);
INSERT INTO OPERATION VALUES (383,'TS',300,'26/5/2018',110,111);
INSERT INTO OPERATION VALUES (384,'TS',309,'16/4/2018',110,111);
INSERT INTO OPERATION VALUES (385,'LO',309,'26/3/2018',110,111);
INSERT INTO OPERATION VALUES (386,'AP',310,'18/5/2018',110,111);
INSERT INTO OPERATION VALUES (387,'AP',311,'4/5/2018',110,111);
INSERT INTO OPERATION VALUES (388,'LO',311,'11/5/2018',110,111);
INSERT INTO OPERATION VALUES (389,'AP',315,'13/6/2019',118,111);
INSERT INTO OPERATION VALUES (390,'HB',316,'23/7/2019',118,111);
INSERT INTO OPERATION VALUES (391,'LO',312,'22/6/2019',118,111);
INSERT INTO OPERATION VALUES (392,'HT',341,'28/8/2019',118,112);
INSERT INTO OPERATION VALUES (393,'HT',340,'27/8/2019',118,112);
INSERT INTO OPERATION VALUES (394,'LO',491,'26/4/2020',103,112);


REM***********************
REM  OBSERVATION TABLE
REM***********************
INSERT INTO OBSERVATION VALUES (205,'2/2/2011',1500,'Temp',38,114);
INSERT INTO OBSERVATION VALUES (274,'4/9/2010',0601,'Temp',39,116);
INSERT INTO OBSERVATION VALUES (275,'1/9/2010',1400,'Pulse',64,115);
INSERT INTO OBSERVATION VALUES (275,'1/9/2010',1400,'Temp',38,115);
INSERT INTO OBSERVATION VALUES (275,'3/9/2010',1800,'Temp',40,116);
INSERT INTO OBSERVATION VALUES (275,'3/9/2010',2200,'Temp',40,116);
INSERT INTO OBSERVATION VALUES (275,'4/9/2010',0610,'Pulse',82,116);
INSERT INTO OBSERVATION VALUES (275,'4/9/2010',0610,'Temp',38,116);
INSERT INTO OBSERVATION VALUES (277,'24/9/2010',0600,'Temp',39,115);
INSERT INTO OBSERVATION VALUES (284,'5/12/2015',0600,'Temp',39,115);
INSERT INTO OBSERVATION VALUES (284,'5/12/2015',0600,'Pulse',89,115);
INSERT INTO OBSERVATION VALUES (284,'6/12/2015',0600,'Temp',37,115);
INSERT INTO OBSERVATION VALUES (284,'6/12/2015',0600,'Pulse',87,115);
INSERT INTO OBSERVATION VALUES (285,'7/5/2016',0600,'Temp',38,115);
INSERT INTO OBSERVATION VALUES (285,'8/5/2016',0600,'Temp',38,115);
INSERT INTO OBSERVATION VALUES (285,'8/5/2016',0600,'Pulse',82,115);
INSERT INTO OBSERVATION VALUES (285,'9/5/2016',0600,'Temp',37,115);
INSERT INTO OBSERVATION VALUES (286,'7/5/2016',0600,'Temp',39,125);
INSERT INTO OBSERVATION VALUES (286,'8/5/2016',0600,'Temp',33,125);
INSERT INTO OBSERVATION VALUES (286,'8/5/2016',0600,'Pulse',86,125);
INSERT INTO OBSERVATION VALUES (286,'9/5/2016',0600,'Temp',36,125);
INSERT INTO OBSERVATION VALUES (287,'7/5/2016',0600,'Temp',35,115);
INSERT INTO OBSERVATION VALUES (287,'8/5/2016',0600,'Temp',37,115);
INSERT INTO OBSERVATION VALUES (287,'8/5/2016',0600,'Pulse',82,125);
INSERT INTO OBSERVATION VALUES (287,'9/5/2016',0600,'Temp',37,125);
INSERT INTO OBSERVATION VALUES (289,'19/5/2016',0600,'Temp',39,115);
INSERT INTO OBSERVATION VALUES (289,'20/5/2016',1400,'Temp',38,115);
INSERT INTO OBSERVATION VALUES (289,'22/5/2016',0800,'Temp',37,115);
INSERT INTO OBSERVATION VALUES (289,'26/5/2016',0700,'Temp',37,115);
INSERT INTO OBSERVATION VALUES (289,'29/5/2016',0700,'Temp',38,115);
INSERT INTO OBSERVATION VALUES (300,'23/4/2018',1400,'Pulse',74,115);
INSERT INTO OBSERVATION VALUES (300,'23/4/2018',1400,'Temp',38,115);
INSERT INTO OBSERVATION VALUES (300,'23/4/2018',1800,'Temp',30,116);
INSERT INTO OBSERVATION VALUES (300,'23/4/2018',2200,'Temp',40,116);
INSERT INTO OBSERVATION VALUES (300,'24/4/2018',0610,'Pulse',82,116);
INSERT INTO OBSERVATION VALUES (300,'24/4/2018',0610,'Temp',38,116);
INSERT INTO OBSERVATION VALUES (303,'13/4/2018',1400,'Pulse',64,125);
INSERT INTO OBSERVATION VALUES (303,'13/4/2018',1400,'Temp',38,125);
INSERT INTO OBSERVATION VALUES (303,'13/4/2018',1800,'Temp',30,125);
INSERT INTO OBSERVATION VALUES (303,'23/4/2018',2200,'Temp',40,116);
INSERT INTO OBSERVATION VALUES (303,'23/4/2018',0610,'Pulse',82,116);
INSERT INTO OBSERVATION VALUES (303,'23/4/2018',0610,'Temp',38,116);
INSERT INTO OBSERVATION VALUES (311,'3/5/2018',1400,'Pulse',54,115);
INSERT INTO OBSERVATION VALUES (311,'4/5/2018',1400,'Temp',38,115);
INSERT INTO OBSERVATION VALUES (311,'3/5/2018',1800,'Temp',40,116);
INSERT INTO OBSERVATION VALUES (311,'4/5/2018',2200,'Temp',41,116);
INSERT INTO OBSERVATION VALUES (311,'4/5/2018',1800,'Temp',39,116);
INSERT INTO OBSERVATION VALUES (311,'5/5/2018',0610,'Pulse',72,116);
INSERT INTO OBSERVATION VALUES (311,'5/5/2018',0610,'Temp',38,116);
INSERT INTO OBSERVATION VALUES (310,'13/5/2018',1400,'Pulse',84,125);
INSERT INTO OBSERVATION VALUES (310,'13/5/2018',1400,'Temp',28,125);
INSERT INTO OBSERVATION VALUES (310,'14/5/2018',1800,'Temp',60,125);
INSERT INTO OBSERVATION VALUES (310,'15/5/2018',2200,'Temp',40,116);
INSERT INTO OBSERVATION VALUES (310,'16/5/2018',0610,'Pulse',92,116);
INSERT INTO OBSERVATION VALUES (310,'16/5/2018',0610,'Temp',35,116);
INSERT INTO OBSERVATION VALUES (341,'22/8/2019',0610,'Temp',39,116);
INSERT INTO OBSERVATION VALUES (340,'25/8/2019',0610,'Temp',39,116);
INSERT INTO OBSERVATION VALUES (340,'25/8/2019',0610,'Pulse',75,116);
INSERT INTO OBSERVATION VALUES (340,'26/8/2019',0610,'Temp',37,116);
INSERT INTO OBSERVATION VALUES (340,'26/8/2019',0610,'Pulse',70,116);
INSERT INTO OBSERVATION VALUES (340,'27/8/2019',0610,'Pulse',68,116);
INSERT INTO OBSERVATION VALUES (340,'27/8/2019',0610,'Temp',37,116);
INSERT INTO OBSERVATION VALUES (340,'29/8/2019',0610,'Pulse',73,116);
INSERT INTO OBSERVATION VALUES (490,'17/4/2020',0600,'Temp',38,125);
INSERT INTO OBSERVATION VALUES (490,'18/4/2020',0600,'Temp',37,125);
INSERT INTO OBSERVATION VALUES (490,'19/4/2020',0600,'Temp',38,125);

select town, c.count(2021- to_char(birth_date,'YYYY')) 100/count( ) as "Population" from person, person c group by town

Using Apex Oracle here, I need to set a condition for c.count where it only takes into account >60, but whenever I put the condition in, errors pop up, would greatly appreciate any help possible.

Answer 1

I'm assuming you don't really need a cross join of 'person' with 'person'. So I'm dropping that logic from the sources.

I don't have and Oracle instance to work with, but I believe the code below, which uses a case statement to achieve your conditional need, should work for you:

select       town, 
             c.count(
                 case when ap.age > 60 then ap.age end
             ) 100 / count() as "Population" 
from         person 
cross apply  (select age = 2021 - to_char(birth_date,'YYYY')) ap
group by     town