Say I have a table that looks like:
ID Name Age Co
1 Adls 15 US
2 sldkl 14 FR
3 sldke 16 UK
4 sldee 17 IN
I want to add values to the table and have the ID incremented. ID is the primary key, and I set is Identity under column properties to 'Yes' and identity increment to 1.
So basically, I am doing:
Insert Into TableName(Name, Age, Co)
Values(slkdje, 19, CH)
(sldjklse, 20, AU)
(slfjke, 12, PK)
But, I am getting errors that the primary key is null, and therefore this operation in invalid. How would I add the values, but get the primary key values to increment?
here is a great example for what you want here
here is also a sql query that is copy and paste that will show my example.
create table #temp(
ID int IDENTITY(1,1) PRIMARY KEY,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Age int
)
insert into #temp(LastName) values('billy'),('bob')
select * from #temp
drop table #temp;
hope this helps dude.
Related
I'm on Postgresql 13.
I want a table(rooms) that assume the default value of "1" if I delete from building which is the "parent table"
This is my sql code
DROP TABLE rooms;
DROP TABLE buildings;
CREATE TABLE buildings (
building_no INT default 1 primary key,
building_name VARCHAR(255),
address VARCHAR(255));
CREATE TABLE rooms (
room_no INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
room_name VARCHAR(255),
building_no INT default 1,
FOREIGN KEY (building_no) REFERENCES buildings (building_no) ON DELETE SET default );
I insert the values into the tables
insert into buildings values (1,'Building1','Street 33');
insert into buildings values (2,'Build-B','Street 34');
insert into rooms values (1,'Room 1',1);
insert into rooms values (2,'Room 2',2);
Then I delete from buildings
delete from buildings;
When I delete from buildings instead of make the default value of 1 as I ask it set the value NULL.
test=> select * from rooms;
room_no | room_name | building_no
---------+-----------+-------------
1 | Room 1 |
2 | Room 2 |
What's wrong in my sql code?
By deleting all of the records in buildings, the default value of 1 in the rooms table violates the FK constraint. Therefore, it's going to set it to NULL. If you were to delete all buildings EXCEPT building 1, you will not encounter the behavior you are describing.
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.
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) :-
I'm frankly new to sql and this is a project I'm doing.
I would like to know if there's a way to connect one column in one table to another table when creating tables. I know of the join method to show results of, but I want to minimized my code as possible.
CREATE TABLE players (
id INT PRIMARY KEY, -->code I want connect with table match_record
player_name CHARACTER
);
CREATE TABLE match_records (
(id INT PRIMARY KEY /*FROM players*/), --> the code I want it to be here
winner INT,
loser INT
);
CREATE TABLE players (
id INT not null PRIMARY KEY, -->code I want connect with table match_record
player_name CHARACTER
);
CREATE TABLE match_records (
id INT not null PRIMARY KEY references players(id), --> the code I want it to be here
winner INT,
loser INT
);
this way you restrict that match_records.id is only from players.id:
t=# insert into match_records select 1,1,0;
ERROR: insert or update on table "match_records" violates foreign key constraint "match_records_id_fkey"
DETAIL: Key (id)=(1) is not present in table "players".
So I add players:
t=# insert into players(id) values(1),(2);
INSERT 0 2
And now it allows insert:
t=# insert into match_records select 1,1,0;
INSERT 0 1
update
https://www.postgresql.org/docs/current/static/app-psql.html#APP-PSQL-PROMPTING
%#
If the session user is a database superuser, then a #, otherwise a >.
(The expansion of this value might change during a database session as
the result of the command SET SESSION AUTHORIZATION.)
in this way:
CREATE TABLE new_table as SELECT id,... from old_table where id = 1;
I'm having trouble from Inserting 1 Primary Value (Increment) of TABLE to another TABLE (Foreign Key)
Table 1 has the Primary key of Student Number; if i enter values for last and first name from TABLE 1 then the student number will automatically giving it's own value because of Increment, and else if i entered from TABLE 2, I want the value of Student Number from TABLE i will increment even the value of Last and First name if TABLE 1 is NULL
Table 1
(PK)Student_# | Last_Name | First_Name
...........1...........|........a..........|..........b.......
...........2...........|........c..........|..........b.......
Table 2
(FK)Student_# | Year_Level | Section
...........NULL................|..........2nd Year......|.....C1 .........
...........NULL................|..........3rd Year......|.....D1 .........
Needed
(FK)Student_# | Year_Level | Section
..............1...................|..........2nd Year......|.....C1 .........
..............2...................|..........3rd Year......|.....D1 .........
It sounds to me that you need a primary key with an identity seed on table2 and also a foreign key to the student table:
(PK/Identity) Table2ID | (FK)Student_# | Year_Level | Section
This way you can insert the student_# when you insert the record into table 2 and also be able to give each row in table2 a unique identifier
CREATE TABLE Table2
(
Table2ID INT IDENTITY(1,1) PRIMARY KEY
,Student_# INT NOT NULL FOREIGN KEY REFERENCES Table1(Student_#)
,Year_Level NVARCHAR(255) --Use whatever data type you need
,Section NVARCHAR(255) --Use whatever data type you need
)
I have assumed you are using sql server as you have not specified in your question. You may need to change this query for a different RDBMS.
I need help in auto populating the primary key values in foreign key table while inserting data in foreign key table. For Example: I have created table:
create table Patient
(
PatientId int IDENTITY(1,1) primary key,
FirstName varchar(50),
SurName varchar(50),
Gender char(20),
)
Say 5 rows are there in this Patient Table:
Say First Row value is: 1, Priya, Kumari, Female
I have created the Guardians Table:
create table Guardians
(
GuardiansId int identity(1,1) primary key,
PatientId int foreign key references Patient(PatientId),
FirstName varchar(50),
SurName varchar(50),
Gender char(20),
RelationToPatient varchar(50),
)
In this table Insert operations are like this:
insert into Guardians(FirstName, SurName, Gender,RelationToPatient)values('Sumit','Kumar','Male','Wife')
While selecting the Guardians Table PatientId showing NULL values: My query is while inserting the values in Guardians Table PatientId should be auto Populated which will come from Patient Table...
My second problem is: How to create the Identity column as varchar. For example: suppose I want to increment my Guardians Table with 'GRD0001', 'GRD0002', 'GRD0003' like this...
Thanks,
S.D
Your question is not very clear - what exactly do you want to do??
When you insert something into the Guardians table, you want to automatically also insert it into the Patients table? I don't quite follow. Can you make a complete example, maybe??
If you need to capture the insert IDENTITY value from the Patient table, do this:
DECLARE #NewPatientID INT
INSERT INTO dbo.Patient(fields) VALUES(.......)
SET #NewPatientID = SCOPE_IDENTITY()
INSERT INTO dbo.Guardians(PatientId, ......) VALUES(#NewPatientID, ......)
As for your second question: leave you GuardiansId IDENTITY as it is (only an INT column can be an IDENTITY and you want to keep that - trust me!) and add a computed column to your table:
ALTER TABLE dbo.Guardians
ADD GuardianIDWithPrefix AS
'GDR' + RIGHT('0000' + CAST(GuardiansId AS VARCHAR(4)), 4) PERSISTED
Since it's a PERSISTED field, you can even index on it and use it like a normal field in every respect.
That should do the trick!