I have some problems with a Query that I can not get out, the structure of the tables is as follows:
child
CREATE TABLE CHILD(
child_id SMALLINT,
child_name VARCHAR(255) NOT NULL,
birth_date DATE NOT NULL,
gender VARCHAR(255) NOT NULL,
address VARCHAR(255),
city VARCHAR(255),
CONSTRAINT PK_CHILD PRIMARY KEY(child_id)
letter
CREATE TABLE LETTER(
letter_id SMALLINT,
arrival_date DATE NOT NULL,
number_toys INTEGER NOT NULL,
delivery_mode VARCHAR(255) NOT NULL,
child_id SMALLINT,
CONSTRAINT PK_LETTER PRIMARY KEY(letter_id),
CONSTRAINT CHILD_FK FOREIGN KEY (child_id) REFERENCES CHILD(child_id)
);
wished_toy
CREATE TABLE WISHED_TOY(
letter_id SMALLINT,
toy_id SMALLINT,
CONSTRAINT PK_WISHED_TOY PRIMARY KEY(letter_id, toy_id),
CONSTRAINT LETTER_FK FOREIGN KEY (letter_id) REFERENCES LETTER(letter_id)
CONSTRAINT LETTER_FK FOREIGN KEY (toy_id) REFERENCES TOY(toy_id)
);
toy
CREATE TABLE TOY(
toy_id SMALLINT,
toy_name VARCHAR (255) NOT NULL,
price DECIMAL NOT NULL,
toy_type VARCHAR(255) NOT NULL,
manufacturer VARCHAR(255) NOT NULL,
CONSTRAINT PK_TOY PRIMARY KEY(toy_id),
);
I have to design a query that allows to obtain for each girl born before 2010 the
total number of toys you have ordered. The result must also include
those girls who have not written any letters. Specifically we want the
identifier of the girl, her name and city and the total number of toys ordered
(such as Total_number).
in the gender column of the child table can only be "m" of masculine or "f" of feminine
Do I have to use join?
the part that I have is this
select c.child_id,c.child_name,c.city
from letter l
join child c
on c.child_id=l.child_id
where c.gender='m' and c.birth_date between <='2010/01/01';
select c.child_id,c.child_name,c.city, coalesce( number_toys,0) counted
from
Child c
left outer join letter l
on c.child_id=l.child_id
where c.gender='m' and c.birth_date between <='2010/01/01';
Or
select c.child_id,c.child_name,c.city, count(wt.letter_id) actualToys
from
Child c
left outer join letter l
on c.child_id=l.child_id
left outer join wished_toy wt on l.letter_id=wt.letter_id
where c.gender='m' and c.birth_date between <='2010/01/01'
Group by
c.child_id,c.child_name,c.city
To count the toys referenced by database rows rather than the pre defined count
Related
I am trying to write a query to display information, but when I use INNER JOIN I am getting duplicate ID fields. My tables and query are below. I am getting duplicate columns for wrestlerID. could it be my PK constraints?
CREATE TABLE WRESTLER
(
WrestlerID CHAR(6) NOT NULL,
WrestlerFirst VARCHAR2(15) NOT NULL,
WrestlerLast VARCHAR2(25) NOT NULL,
WrestlerStyle CHAR(2) NOT NULL,
WrestleKilos NUMERIC(3,0) NOT NULL,
WrestleMeters NUMERIC(3,2),
WrestleCity VARCHAR2(40) NOT NULL,
WrestlerState CHAR(2) NOT NULL,
WrestlerBirthdate Date,
CONSTRAINT WRESTLER_PK PRIMARY KEY (WrestlerID)
);
CREATE TABLE CLUB
(
ClubID CHAR(5) NOT NULL,
Club VARCHAR2(35) NOT NULL,
WrestlerID CHAR(6) NOT NULL,
CONSTRAINT CLUB_PK PRIMARY KEY (ClubID, WrestlerID),
CONSTRAINT CLUB_FK
FOREIGN KEY (WrestlerID) REFERENCES WRESTLER(WrestlerID)
);
CREATE TABLE SCHOOL
(
SchoolID VARCHAR2(10) NOT NULL,
School VARCHAR2(35) NOT NULL,
WrestlerID CHAR(6) NOT NULL,
CONSTRAINT SCHOOL_PK PRIMARY KEY (SchoolID, WrestlerID),
CONSTRAINT SCHOOL_FK
FOREIGN KEY (WrestlerID) REFERENCES WRESTLER(WrestlerID)
);
CREATE TABLE MEDAL
(
WrestlerID CHAR(6) NOT NULL,
WorldMedal NUMERIC(4,0),
CONSTRAINT MEDAL_PK PRIMARY KEY (WrestlerID, WorldMedal),
CONSTRAINT MEDAL_FK
FOREIGN KEY (WrestlerID) REFERENCES WRESTLER(WrestlerID)
);
SELECT
t1.WrestlerID, t1.WrestlerFirst, t1.WrestlerLast,
t2.WrestlerID, t2.School,
t2.WrestlerID, t3.Club
FROM
WRESTLER t1
INNER JOIN
SCHOOL t2 ON t1.WrestlerID = t2.WrestlerID
INNER JOIN
CLUB t3 ON t1.WrestlerID = t3.WrestlerID;
Fixing my query worked
SELECT
t1.WrestlerID, t1.WrestlerFirst, t1.WrestlerLast,
t2.School,
t3.Club FROM
WRESTLER t1 INNER JOIN
SCHOOL t2 on t1.WrestlerID = t2.WrestlerID INNER JOIN
CLUB t3 on t1.WrestlerID = t3.WrestlerID;
So I have 3 tables referencing cars, assurance and accident.
I want to know the brand of vehicles who had the most accidents, compared to others.
I have tried a lot of ways to that, but mostly i only get or all the brands returned or the brand of the car that was registered the most, not the one that had most accidents
These are my tables
create table car(
n_veic bigint not null,
matric varchar(15) not null,
pais_matric text not null,
n_pess bigint not null,
tipo text not null,
cor text not null,
brand text not null,
modelo varchar(15),
primary key(n_veic),
unique(matric),
foreign key (n_pess) references pessoa(n_pess)
);
create table ensurance(
apolice bigint not null,
segurado bigint not null,
car bigint not null,
datai date not null,
dataf date not null,
cobertura numeric(10,2) not null,
primary key(apolice),
unique(segurado, veiculo),
foreign key (segurado) references pessoa(n_pess),
foreign key (car) references car(n_veic)
);
create table accident(
n_acid bigint not null,
pess_segura bigint not null,
veic_seguro bigint not null,
data date not null,
local varchar(255) not null,
descr text not null,
primary key(n_acid),
unique(n_acid, veic_seguro),
foreign key (pess_segura,veic_seguro) references ensurance(segurado, car)
This is what i tried
SELECT marca
FROM veiculo NATURAL JOIN acidente
GROUP BY marca
HAVING count (distinct n_veic)>=ALL
(SELECT count (distinct n_veic)
FROM veiculo NATURAL JOIN acidente
GROUP BY marca);
I think the logic is:
select c.marca, count(*) as num_acidentes
from acidente a join
car c
on a.veic_seguro = c.n_veic
group by c.marca
order by num_acidentes desc;
You can use fetch first 1 row only -- or whatever is appropriate for your database -- to get only one row.
Try this-
Note:
1. Try to avoid NATURAL JOIN and use specific column reference.
2. Rethink DISTINCT for count is really necessary or not.
SELECT TOP 1 marca, COUNT(DISTINCT n_veic)
FROM veiculo
NATURAL JOIN acidente
GROUP BY marca
ORDER BY COUNT(DISTINCT n_veic) DESC
So I am working on a football world cup database. These are my important tables:
CREATE TABLE Countries(
Cid SERIAL PRIMARY KEY,
Name VARCHAR(256) NOT NULL UNIQUE
);
CREATE TABLE Stadiums(
Sid SERIAL PRIMARY KEY,
Name VARCHAR(256) NOT NULL UNIQUE,
Cid INT REFERENCES Countries NOT NULL
);
CREATE TABLE Groups(
Gid SERIAL PRIMARY KEY,
Name VARCHAR(64) NOT NULL,
TYear SMALLINT REFERENCES Tournaments NOT NULL
);
CREATE TABLE Teams(
Tid SERIAL PRIMARY KEY,
Cid INT REFERENCES Countries NOT NULL,
Gid INT REFERENCES Groups NOT NULL
);
CREATE TABLE Matches(
Mid INT PRIMARY KEY,
HomeTid INT REFERENCES Teams NOT NULL,
VisitTid INT REFERENCES Teams NOT NULL,
HomeScore SMALLINT NOT NULL,
VisitScore SMALLINT NOT NULL,
MatchDate DATE NOT NULL,
MatchType VARCHAR(64) NOT NULL,
Sid INT REFERENCES Stadiums NOT NULL
);
CREATE TABLE tempmatches(
year INTEGER,
host_country VARCHAR(255),
match_id INTEGER,
type VARCHAR(255),
date DATE,
location1 VARCHAR(255),
team1 VARCHAR(255),
team2 VARCHAR(255),
score1 INTEGER,
score2 INTEGER
);
so my current problem is that I need to populate the columns HomeTid and VisitId of the Matches table with the tid's from the team's table that corresponds with the country of that team from the countries table but I'm not sure how to do that. I tried a few queries but none of them seemed to work. Has anyone an idea on how to solve this?
Using JOIN keyword you can combine 2 tables data.
Here, in this case, you have to use 3-way join.
Eg:
3-way JOIN can be used in this way:
SELECT * FROM table1 JOIN table2 ON table1.col1=table2.col2 JOIN table3 ON table3.col3=table.col1;
Here the 2 tables will get joined based on the columns mentioned after the "ON" keyword.
Here is a reference link in which JOIN is explained clearly
https://www.w3schools.com/sql/sql_join.asp
Use JOIN operation. In SQL it helps to combine several tables(queries) in one
This concerns Oracle SQL.
Considering the following 3 tables:
TRIP_SEGMENT:
CREATE TABLE TRIP_SEGMENT(
SEG_ID NUMBER(6) NOT NULL,
DIRECTION VARCHAR(8) NOT NULL,
DEPARTURE_LOCATION VARCHAR(50) NOT NULL,
DESTINATION VARCHAR(50) NOT NULL,
SEGMENT_PRICE NUMBER(5,2) NULL,
TRIP_ID NUMBER(6) NOT NULL,
CONSTRAINT chk_SEG_DIRECTION CHECK (DIRECTION IN ('Outbound','Inbound')),
CONSTRAINT pk_SEGMENT PRIMARY KEY (SEG_ID),
CONSTRAINT fk_TRIP_ID FOREIGN KEY (TRIP_ID) REFERENCES TRIP(TRIP_ID)
);
TRANSPORTATION:
CREATE TABLE TRANSPORTATION(
TRANSP_BOOK_ID NUMBER(6) NOT NULL,
TRANSP_PRICE NUMBER(5,2) NULL,
DEPARTURE_DATE DATE NULL,
ARRIVAL_DATE DATE NULL,
EXT_BOOK_ID NUMBER(6) NULL,
SEG_ID NUMBER(6) NOT NULL,
SERV_TYPE_ID NUMBER(3) NOT NULL,
PARTNER_ID NUMBER(3) NULL,
CONSTRAINT pk_TRANSP_BOOK_ID PRIMARY KEY (TRANSP_BOOK_ID),
CONSTRAINT fk_TRANSP_SEG_ID FOREIGN KEY (SEG_ID) REFERENCES TRIP_SEGMENT(SEG_ID),
CONSTRAINT fk_TRANSP_SERV_ID FOREIGN KEY (SERV_TYPE_ID) REFERENCES SERVICE_TYPE(SERV_TYPE_ID),
CONSTRAINT fk_TRANSP_PARTNER_ID FOREIGN KEY (PARTNER_ID) REFERENCES PARTNER(PARTNER_ID)
);
PARTNER:
CREATE TABLE PARTNER(
PARTNER_ID NUMBER(3) NOT NULL,
PARTNER_NAME VARCHAR(50) NOT NULL,
CONTACT_FNAME VARCHAR(20) NOT NULL,
CONTACT_LNAME VARCHAR(20) NOT NULL,
ADDRESS VARCHAR(100) NULL,
PHONE_NO NUMBER(20) NOT NULL,
EMAIL VARCHAR(50) NULL,
SERV_TYPE_ID NUMBER(3) NOT NULL,
CONSTRAINT pk_PARTNER_ID PRIMARY KEY (PARTNER_ID),
CONSTRAINT fk_PART_SERV_ID FOREIGN KEY (SERV_TYPE_ID) REFERENCES SERVICE_TYPE(SERV_TYPE_ID)
);
I wanted to create a FULL OUTER JOIN like this:
SELECT TS.SEG_ID, TS.DEPARTURE_LOCATION, TS.DESTINATION, P.PARTNER_NAME
FROM TRIP_SEGMENT TS
FULL OUTER JOIN TRANSPORTATION T
ON TS.SEG_ID = T.SEG_ID
FULL OUTER JOIN PARTNER P
ON T.PARTNER_ID = P.PARTNER_ID;
...but have it restricted to PARTNER.PARTNER_ID < 6. If I just add a WHERE clause at the end of the JOIN, this will restrict all the values to those where there is an association with PARTNER.PARTNER_ID < 6, therefore defeating the purpose of the FULL OUTER JOIN.
So far, I've come up with this solution:
First, create a table that only contains PARTNER.PARTNER_ID < 6 :
CREATE TABLE TRANSPORTATION_PARTNER AS SELECT * FROM PARTNER WHERE PARTNER_ID < 6;
Then, use that table in the FULL OUTER JOIN instead:
SELECT TS.SEG_ID, TS.DEPARTURE_LOCATION, TS.DESTINATION, TP.PARTNER_NAME
FROM TRIP_SEGMENT TS
FULL OUTER JOIN TRANSPORTATION T
ON TS.SEG_ID = T.SEG_ID
FULL OUTER JOIN TRANSPORTATION_PARTNER TP
ON T.PARTNER_ID = TP.PARTNER_ID;
This works fine and it demonstrates what I'm trying to achieve, however I was wondering if there is a way of doing in one single query AND using a subquery.
Thank you!
YES, just do something like :
SELECT TS.SEG_ID, TS.DEPARTURE_LOCATION, TS.DESTINATION, P.PARTNER_NAME
FROM TRIP_SEGMENT TS
FULL OUTER JOIN TRANSPORTATION T
ON TS.SEG_ID = T.SEG_ID
FULL OUTER JOIN (SELECT *
FROM PARTNER
WHERE PARTNER.PARTNER_ID < 6) P
ON T.PARTNER_ID = P.PARTNER_ID;
You are placing restrictions on the rows to be selected so you can use LEFT JOIN instead of the FULL OUTER JOIN. Try something like
SELECT TS.SEG_ID, TS.DEPARTURE_LOCATION, TS.DESTINATION, P.PARTNER_NAME
FROM TRIP_SEGMENT TS
FULL OUTER JOIN TRANSPORTATION T
ON TS.SEG_ID = T.SEG_ID
LEFT OUTER JOIN PARTNER P
ON T.PARTNER_ID = P.PARTNER_ID AND P.Partner_ID = 6;
I have the following problem to solve in SQL :
d) A query that provides management information on take up of the various types of activities on offer. For each type of activity, the query should show the total number of individuals who took that type of activity and the average number of individuals taking each type of activity.
Here are my tables :
CREATE TABLE accommodations
(
chalet_number int PRIMARY KEY,
chalet_name varchar(40) NOT NULL,
no_it_sleeps number(2) NOT NULL,
indivppw number(4) NOT NULL
)
CREATE TABLE supervisors
(
supervisor_number int PRIMARY KEY,
supervisor_forename varchar(30) NOT NULL,
supervisor_surname varchar(30) NOT NULL,
mobile_number varchar(11) NOT NULL
)
CREATE TABLE visitors
(
visitor_ID int PRIMARY KEY,
group_ID int NOT NULL,
forename varchar(20) NOT NULL,
surname varchar(20) NOT NULL,
dob date NOT NULL,
gender varchar(1) NOT NULL
)
CREATE TABLE activities
(
activity_code varchar(10) PRIMARY KEY,
activity_title varchar(20) NOT NULL,
"type" varchar(20) NOT NULL
)
CREATE TABLE "groups"
(
group_ID int PRIMARY KEY,
group_leader varchar(20) NOT NULL,
group_name varchar(30)
number_in_group number(2) NOT NULL
)
CREATE TABLE bookings
(
group_ID int NOT NULL,
start_date date NOT NULL,
chalet_number int NOT NULL,
no_in_chalet number(2) NOT NULL,
start_date date NOT NULL,
end_date date NOT NULL,
CONSTRAINT bookings_pk PRIMARY KEY(group_ID, chalet_number));
CREATE TABLE schedule
(
schedule_ID int PRIMARY KEY,
activity_code varchar(10) NOT NULL,
time_of_activity number(4,2) NOT NULL,
am_pm varchar(2) NOT NULL,
"date" date NOT NULL
)
CREATE TABLE activity_bookings
(
visitor_ID int NOT NULL,
schedule_ID int NOT NULL,
supervisor_number int NOT NULL,
comments varchar(200),
CONSTRAINT event_booking_pk PRIMARY KEY(visitor_ID, schedule_ID));
ALTER TABLE visitors
ADD FOREIGN KEY (group_ID)
REFERENCES "groups"(group_ID)
ALTER TABLE Schedule
ADD FOREIGN KEY (activity_code)
REFERENCES activities(activity_code)
ALTER TABLE bookings
ADD FOREIGN KEY (group_ID)
REFERENCES "groups"(group_ID)
ALTER TABLE bookings
ADD FOREIGN KEY (chalet_number)
REFERENCES accommodations(chalet_number)
ALTER TABLE activity_bookings
ADD FOREIGN KEY (visitor_ID)
REFERENCES visitors(visitor_ID)
ALTER TABLE activity_bookings
ADD FOREIGN KEY (schedule_ID)
REFERENCES schedule(schedule_ID)
ALTER TABLE activity_bookings
ADD FOREIGN KEY (supervisor_number)
REFERENCES supervisors(supervisor_number)
I have the following solution:
SELECT activities."type", 'overalltotal' AS OT, ('overalltotal' / 'activities') AS AVG
FROM activities, schedule
WHERE 'overalltotal' = (SELECT SUM(COUNT(schedule_ID))
FROM activities, schedule
WHERE schedule.activity_code = activities.activity_code
GROUP BY activities."type"
)
AND 'activities' = (SELECT COUNT(DISTINCT activities."type")
FROM activities
)
AND schedule.activity_code = activities.activity_code
GROUP BY activities."type";
I have implemented sample data and code to check the variables above:
SELECT SUM(COUNT(schedule_ID))
FROM activities, schedule
WHERE schedule.activity_code = activities.activity_code
GROUP BY activities."type";
Result : 20
SELECT COUNT(DISTINCT activities."type")
FROM activities;
Result : 5
However when running the code :
ORA-01722: invalid number
01722. 00000 - "invalid number"
*Cause:
*Action:
EDIT:
Using Dave's Code i have the following output:
Snowboarding 15
sledding 19
Snowmobiling 6
Ice Skating 5
Skiing 24
How would i do the final part of the question?
and the average number of individuals taking each type of activity.
You must use double quotes around column names in Oracle, not single quotes. For example, "overalltotal". Single quotes are for text strings, which is why you're getting an invalid number error.
EDIT: This is probably the type of query you want to use:
SELECT activities."type", COUNT(*) AS total, COUNT(*)/(COUNT(*) OVER ()) AS "avg"
FROM activities a
JOIN schedule s ON a.activity_code=s.activity_code
JOIN activity_bookings ab ON s.schedule_ID=ab.schedule_ID
GROUP BY activities."type";
Basically, because each activity booking has one visitor id, we want to get all the activity bookings for each activity. We have to go through schedule to do that. They we group the rows by the activity type and count how many activity bookings we have for each type.