How do you make a nested select with a restriction (WHERE) - mysql

Question

I have a database for a small calendar app in which people are stored in the clients table, dates are stored in the table calendarDate and since the relations are many to many there is a connecting table called client_date which holds both of their ids.
I want to make a nested select to get all the dates for a particular person lets say with id = 2.
I came up with this, but it prints all of the dates and asigns them to the person with that id, instead of just printing the only ones he is asigned to:
SELECT c.username
, c.country
, d.day
, d.month
, d.year
, d.dayOfWeek
, d.weekOfYear
, d.emotionId
, d.id
from clients as c
join calendarDate as d
on d.id in (SELECT dateId
from client_date
WHERE clientId in (SELECT id
from clients )
)
where c.id = 2;
Is there something I am doing wrong or is there another way to make a nested select statement ?
My database and data:
DROP DATABASE IF EXISTS calendar;
CREATE DATABASE calendar;
USE calendar;
CREATE TABLE clients(
id INT AUTO_INCREMENT PRIMARY KEY,
username VARCHAR(100) NOT NULL UNIQUE,
joinedOnDate DATE NOT NULL,
country VARCHAR(100) NOT NULL
);
CREATE TABLE emotions(
id INT NOT NULL PRIMARY KEY,
name VARCHAR(100) NOT NULL UNIQUE,
value DOUBLE
);
CREATE TABLE calendarDate(
id INT AUTO_INCREMENT PRIMARY KEY,
day INT NOT NULL,
month INT NOT NULL,
year INT NOT NULL,
dayOfWeek VARCHAR(20) NOT NULL,
weekOfYear int NOT NULL,
emotionId INT NOT NULL,
CONSTRAINT FOREIGN KEY (emotionId)
REFERENCES emotions( id )
);
CREATE TABLE client_date(
dateId INT NOT NULL,
clientId INT NOT NULL,
CONSTRAINT FOREIGN KEY ( dateId )
REFERENCES calendarDate( id ) ,
CONSTRAINT FOREIGN KEY ( clientId )
REFERENCES clients( id ) ,
UNIQUE KEY( dateId, clientId )
);
USE calendar;
INSERT INTO emotions (id, name, value) VALUES
(0, 'None', 1),
(1, 'Excited', 2.0),
(2, 'Happy', 2.0),
(3, 'Positive', 1.5),
(4, 'Average', 1.0),
(5, 'Mixed', 1),
(6, 'Negative', 0.5),
(7, 'Sad', 0);
INSERT INTO clients (username, joinedOnDate, country) VALUES
('Malazzar', DATE(NOW()), 'Bulgaria'),
('Preslava981', DATE(NOW()), 'Bulgaria'),
('Thusnake', DATE(NOW()), 'United Kingdom');
INSERT INTO calendarDate (day, month, year, dayOfWeek, weekOfYear, emotionId) VALUES
(1, 1, 2019, 'Tuesday', 1, 0),
(2, 1, 2019, 'Wednesday', 1, 0),
(3, 1, 2019, 'Thursday', 1, 0),
(4, 1, 2019, 'Friday', 1, 0),
(5, 1, 2019, 'Saturday', 1, 0),
(6, 1, 2019, 'Sunday', 1, 0),
(7, 1, 2019, 'Monday', 2, 0),
(8, 1, 2019, 'Tuesday', 2, 0),
(9, 1, 2019, 'Wednesday', 2, 0),
(10, 1, 2019, 'Thursday', 2, 0),
(11, 1, 2019, 'Friday', 2, 0),
(12, 1, 2019, 'Saturday', 2, 0),
(13, 1, 2019, 'Sunday', 2, 0),
(14, 1, 2019, 'Monday', 3, 0);
INSERT INTO client_date (clientId, dateId) VALUES
(1, 1),
(1, 2),
(1, 3),
(1, 4),
(1, 5),
(1, 6),
(1, 7),
(2, 8),
(2, 9),
(2, 10),
(2, 11),
(2, 12),
(2, 13),
(2, 14);
The output I get for the particular client:
Preslava981 Bulgaria 1 1 2019 Tuesday 1 0 1
Preslava981 Bulgaria 2 1 2019 Wednesday 1 0 2
Preslava981 Bulgaria 3 1 2019 Thursday 1 0 3
Preslava981 Bulgaria 4 1 2019 Friday 1 0 4
Preslava981 Bulgaria 5 1 2019 Saturday 1 0 5
Preslava981 Bulgaria 6 1 2019 Sunday 1 0 6
Preslava981 Bulgaria 7 1 2019 Monday 2 0 7
Preslava981 Bulgaria 8 1 2019 Tuesday 2 0 8
Preslava981 Bulgaria 9 1 2019 Wednesday 2 0 9
Preslava981 Bulgaria 10 1 2019 Thursday 2 0 10
Preslava981 Bulgaria 11 1 2019 Friday 2 0 11
Preslava981 Bulgaria 12 1 2019 Saturday 2 0 12
Preslava981 Bulgaria 13 1 2019 Sunday 2 0 13
Preslava981 Bulgaria 14 1 2019 Monday 3 0 14

Answer 1

Your mistake is here:
WHERE clientId in (SELECT id from clients)
Every client ID exists in the clients table. You want this instead:
WHERE clientId = c.id
You could also use a non-corelated subquery instead, which is easier to read:
on (c.id, d.id) in (select clientid, dateid from client_date)
But as has been mentioned by others, a mere join to client_date would do the same job.

Answer 2

Why not just use joins?
select c.username, c.country, d.*
from clients c join
client_date cd
on cd.clientId = c.id join
calendarDate as d
on d.id cd.dateId
where c.id = 2;

Answer 3

I want to make a nested select to get all the dates for a particular
person lets say with id = 2
This can be done with:
select *
from calendarDate
where day in (
select dateId
from client_date
where clientId = 2
)
An equivalent JOIN query would be:
select d.*
from calendarDate d
join client_date cd
on cd.dateId = d.day
where cd.clientId = 2
View on DB Fiddle
Note: The two queries are only equivalent, if there are no duplicates in the client_date table.
If you want to select data from more than one table, then you actualy need to use a JOIN. In that case asking for how to do it without joins, wouldn't make sense.