Build correct logical db - sql

Question

I use 4 table in database.
Example:
Create table applicant(
Id int not null primary key,
IdName integer
idSkill integer,
idContact integer
Constraint initial foreign key (idName) References Initiale(id)
CONSTRAINT contacT foreign key (idContact) References contact(id)
CONSTRAINT Skills foreign key (idSkill) references skill(id))
Create table Initiale(
Id int not null primary key,
firstname text,
middlename text)
Create table contact(
Id int not null primary key,
phone text,
email text)
Create tabke Skills(
Id int not null primary key,,
Nane text)
I want insert data promptly in 4 table,but i not understand, what get id and insert in applicant.

Answer 1

Create tabke Skills ..... will fail. You should use Create table Skills.
Nor should you have Id int not null primary key,, (two commas), this would fail.
You should very likely be using Id INTEGER PRIMARY KEY not Id int not null primary key.
That is because generally an Id column should be a unique identifier of the row. With SQLite INTEGER PRIMARY KEY has a special meaining whilst INT PRIMARY KEY does not.
That is, if INTEGER PRIMARY KEY is used then the column will be an alias of the rowid column which has to be a unique signed 64 bit integer and importantly if no value is provided when inserting a row then SQLite will assign a unique integer. i.e. the all important Id.
This Id will initially be 1, then likely 2, then likely 3 and so on, although there is no guarantee that the Id will be monotonically increasing.
There are additional errors, mainly comma's omitted. The following should work :-
CREATE TABLE IF NOT EXISTS applicant(
Id INTEGER PRIMARY KEY,
IdName integer,
idSkill integer,
idContact integer,
Constraint initial foreign key (idName) References Initiale(id),
CONSTRAINT contacT foreign key (idContact) References contact(id),
CONSTRAINT Skills foreign key (idSkill) references Skills(id));
Create table IF NOT EXISTS Initiale(
Id INTEGER PRIMARY KEY,
firstname text,
middlename text);
Create table IF NOT EXISTS contact(
Id INTEGER PRIMARY KEY,
phone text,
email text);
Create table IF NOT EXISTS Skills(
Id INTEGER PRIMARY KEY,
Nane text);
You could then insert data along the lines of :-
INSERT INTO Initiale (firstname,middlename) -- Note absence of Id so SQLite will generate
VALUES
('Fred','James'), -- very likely id 1
('Alan','Roy'), -- very likely id 2
('Simon','Gerorge')-- very likely id 3
;
INSERT INTO contact -- alternative way of getting Id generated (specify null for Id)
VALUES
(null,'0123456789','email01#email.com'), -- very likely id 1
(null,'0987654321','email02#email.com'), -- very likely id 2
(null,'3333333333','email03.#email.com') -- very likely id 3
;
INSERT INTO Skills (Nane)
VALUES
('Skill01'),('Skill02'),('Skill03') -- very likely id's 1,2 and 3
;
INSERT INTO applicant (IdName,idSkill,idContact)
VALUES
-- First applicant
(2, -- Alan Roy
3, -- Skill 3
1), -- Contact 0123456789 )
-- Second Applicant
(3, -- Simon George
3, -- Skill 3
2), -- Contact 0987654321 )
-- Third Applicant
(2, -- Alan Roy again????
1, -- Skill 1
3), -- contact 3333333333)
(1,1,1) -- Fred James/ Skill 1/ Contact 0123456789
--- etc
;
Noting that Rows on the Initiale, Contact and Skills table MUST exists before insertions can be made into the Applicant table.
You could then run a query such as :-
SELECT * FROM applicant
JOIN Initiale ON Initiale.Id = idName
JOIN contact ON contact.Id = idContact
JOIN Skills ON Skills.Id = idSkill
This would result in (using the data as inserted above) :-