How to join tables together via Ids using SQLite? - sql

I am having trouble joining parts of tables. I want first and last names of the people and whatever their interest is to be joined together. I get this error message: "[1] [SQLITE_ERROR] SQL error or missing database (ambiguous column name: pi.PersonID)"
CREATE TABLE people (
PersonID INTEGER PRIMARY KEY AUTOINCREMENT,
FirstName VARCHAR(100),
LastName VARCHAR(100)
);
INSERT INTO people (FirstName, LastName)
VALUES ('Walter', 'White'),
('Jesse', 'Pinkman'),
('Saul', 'Goodman');
SELECT * FROM people;
CREATE TABLE interests (
InterestID INTEGER PRIMARY KEY AUTOINCREMENT,
Interest VARCHAR(100)
);
INSERT INTO interests (Interest)
values ('Swimming'),
('Basketball'),
('Running');
SELECT * FROM interests;
CREATE TABLE persons_interests (
PersonID INTEGER,
InterestID INTEGER,
PRIMARY KEY (PersonID, InterestID),
FOREIGN KEY (PersonID) REFERENCES people,
FOREIGN KEY (InterestID) REFERENCES interests
);
DROP TABLE persons_interests;
INSERT INTO persons_interests (PersonID, InterestID)
VALUES (1, 3),
(2, 2),
(3, 3);
SELECT * FROM persons_interests;
SELECT FirstName, LastName, Interest FROM people p, interests i
JOIN persons_interests pi on p.PersonID = pi.PersonID
JOIN persons_interests pi on i.Interest = pi.InterestID;

Don't mix implicit an explicit joins! You seem to want:
select p.firstname, p.lastname, i.interest
from people p
inner join persons_interests pi on pi.personid = p.personid
inner join interests i on i.interestid = pi.interestid;
Here, each table appears just once in the from clause, with the relevant join conditions.

Related

Find all the persons which does not contain the provided resources

Below are the tables
CREATE TABLE Person(
PersonID INT PRIMARY KEY,
FirstName VARCHAR(10),
LastName VARCHAR(10));
CREATE TABLE Resources(
ResourceID CHAR(3) PRIMARY KEY
);
CREATE TABLE PR (
PersonID INT,
ResourceID CHAR(3),
CONSTRAINT pkpr PRIMARY KEY (PersonID, ResourceID),
CONSTRAINT fkPersonID FOREIGN KEY (PersonID) REFERENCES Person(PersonID),
CONSTRAINT fkResourceID FOREIGN KEY (ResourceID) REFERENCES Resources(ResourceID));
INSERT INTO Person(PersonID, FirstName, LastName) VALUES (1, 'Bill', 'Smith'),(2, 'John','Jones'), (3, 'Tim', 'Jolt');
INSERT INTO Resources (ResourceID) VALUES ('ABC'),('DEF'),('HIJ');
INSERT INTO PR (PersonID, ResourceID) VALUES (1,'ABC'),(1,'DEF'),(2,'ABC'), (2,'HIJ'), (1,'HIJ'), (3, 'DEF');
How to find all the persons which does not have resources ('ABC', 'HIJ') ?
With above inserted data it should return person Tim Jolt
I am using PostgreSql.
So your main source of entity is the Person table. And you need to ignore all Persons which have the given resources.
So the SQL will be like below.
select PersonID from Person where PersonID not in ( select PersonID from PR where ResourceID in ('ABC', 'DEF'))
You can write your query in following 4 ways:
Using NOT IN: same answered by Pratik Soni
select personid from person
where personid not in ( select personid from PR where resourceid in ('ABC', 'HIJ'))
Using NOT EXIST:
select personid from person t1
where not exists (select 1 from PR where personid=t1.personid and resourceid in ('ABC', 'HIJ'))
Using <> ALL:
SELECT personid FROM person WHERE
personid <> ALL(select personid from PR where resourceid in ('ABC', 'HIJ'))
Using LEFT JOIN and IS NULL
SELECT p.personid
FROM person p
LEFT JOIN PR r ON p.personid = r.personid AND r.resourceid in ('ABC', 'HIJ')
where r.personid is null
All 4 methods have their own pros and cons. No body can predict the performance without seeing Explain Analyze result. So check the execution plan using all above queries with real data and decide accordingly what method you should adopt.
DEMO

Aggregate SQLite query across multiple tables using JSON1

I can't get my head around the following problem. The other day I learned how to use the JSON1 family of functions, but this time it seems to be more of an SQL issue.
This is my database setup:
CREATE TABLE persons(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT UNIQUE)
CREATE TABLE interests(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT UNIQUE)
CREATE TABLE persons_interests(person INTEGER, interest INTEGER, FOREIGN KEY(person) REFERENCES persons(id), FOREIGN KEY(interest) REFERENCES interests(id))
INSERT INTO persons(name) VALUES('John')
INSERT INTO persons(name) VALUES('Jane')
INSERT INTO interests(name) VALUES('Cooking')
INSERT INTO interests(name) VALUES('Gardening')
INSERT INTO interests(name) VALUES('Relaxing')
INSERT INTO persons_interests VALUES(1, 1)
INSERT INTO persons_interests VALUES(1, 2)
INSERT INTO persons_interests VALUES(2, 3)
Based on this data I'd like to get the following output, which is all interests of all persons aggregated into a single JSON array:
[{name: John, interests:[{name: Cooking},{name: Gardening}]}, {name: Jane, interests:[{name: Relaxing}]}]
Now the following is what I tried to do. Needless to say, this doesn't give me what I want:
SELECT p.name, json_object('interests', json_group_array(json_object('name', i.name))) interests
FROM persons p, interests i
JOIN persons_interests pi ON pi.person = p.id AND pi.interest = i.id
The undesired output is:
John|{"interests":[{"name":"Cooking"},{"name":"Gardening"},{"name":"Relaxing"}]}
Any help is highly appreciated!
For using json_group_array you must group line , in your case by person , except you want only one row with all your results .
Example 1)
This first version , will give you 1 json object by person , so the result will be N rows for N persons :
SELECT json_object( 'name ',
p.name,
'interests',
json_group_array(json_object('name', i.name))) jsobjects
FROM persons p, interests i
JOIN persons_interests pi ON pi.person = p.id AND pi.interest = i.id
group by p.id ;
Example 2)
This second version , will give return 1 big json array that contains all persons , but you fetch only one row .
SELECT json_group_array(jsobjects)
FROM (
SELECT json_object( 'name ',
p.name,
'interests',
json_group_array(json_object('name', i.name))) jsobjects
FROM persons p, interests i
JOIN persons_interests pi ON pi.person = p.id AND pi.interest = i.id
group by p.id
) jo ;

INSTEAD OF INSERT trigger & Identity column using view

I'm building a database that will store client data for a company. The tables in the DB are normalized, so I have multiple tables that are linked together using Foreign Key Constraints.
Microsoft Access will be used to interface with the database (as a frontend). To make things simpler, I created a view that joins all the required tables together so that end-users can query information without hassle.
The problem I've run into involves INSERTING information into this view. From my understanding, since I have multiple tables in my view, I have to use a trigger with an INSTEAD OF INSERT statement. I've created the trigger; however, I'm unsure how to work with the ID columns in the tables (these act as keys).
I have a MemberBasicInformation table that contains the client's DOB, Name, Gender, etc AND their MemberID. This ID is an IDENTITY column in the table, so it is generated automatically. The problem that I'm running into is that because the identity is automatically generated, I'm unable to grab the identity value that is generated after the insert into the MemberBasicInformation table and insert it into the other related tables. When I attempt to do so, I end up with a Foreign Key constraint violations.
I've tried using ##Identity and Scope_Identity() to no avail. I've listed my view and trigger to give you an idea of how things are set up. I would greatly appreciate if someone could point me in the right direction. I'm truly at a loss.
MEMBER view:
CREATE VIEW [dbo].[Member]
AS
SELECT
dbo.MemberBasic.MemberId, dbo.MemberBasic.FirstName,
dbo.MemberBasic.MiddleInitial, dbo.MemberBasic.LastName,
dbo.MemberBasic.FullName, dbo.MemberBasic.DateOfBirth,
dbo.Gender.Name AS Gender, dbo.MemberBasic.Address,
dbo.MemberBasic.Address2, dbo.MemberBasic.City,
dbo.MemberBasic.State, dbo.MemberBasic.ZipCode,
dbo.MemberBasic.PhoneNumber,
dbo.MemberBasic.SocialSecurityNumber,
dbo.MemberBasic.DriversLicense,
dbo.MemberBasic.EmployerIdentificationNumber,
dbo.MemberBasic.Notes,
dbo.FieldRep.Name AS FieldRepName,
dbo.MemberDetail.DateAssigned AS FieldRepDateAssigned,
dbo.MemberDetail.CPReceivedOn, dbo.MemberDetail.CredentialedOn,
dbo.MemberEligibility.IsActive, dbo.ICO.Name AS ICO,
dbo.MemberEligibility.StartDate AS EligibilityStartDate,
dbo.MemberEligibility.EndDate AS EligibilityEndDate,
dbo.MemberWorkerCompDetail.ExpirationDate AS WorkerCompExpirationDate,
dbo.MemberWorkerCompDetail.AuditDate AS WorkerCompAuditDate,
dbo.WorkerCompTier.Name AS WorkerCompTier,
dbo.MemberAttachment.AttachmentId,
dbo.MemberAttachment.Data AS AttachmentData
FROM
dbo.MemberAttachment
INNER JOIN
dbo.MemberBasic ON dbo.MemberAttachment.MemberId = dbo.MemberBasic.MemberId
INNER JOIN
dbo.MemberCaregiverAssignment ON dbo.MemberAttachment.MemberId = dbo.MemberCaregiverAssignment.MemberId
INNER JOIN
dbo.MemberDetail ON dbo.MemberBasic.MemberId = dbo.MemberDetail.MemberId
INNER JOIN
dbo.MemberEligibility ON dbo.MemberAttachment.MemberId = dbo.MemberEligibility.MemberId
INNER JOIN
dbo.MemberWorkerCompDetail ON dbo.MemberAttachment.MemberId = dbo.MemberWorkerCompDetail.MemberId
INNER JOIN
dbo.Gender ON dbo.MemberBasic.GenderId = dbo.Gender.GenderId
INNER JOIN
dbo.FieldRep ON dbo.MemberDetail.FieldRepId = dbo.FieldRep.FieldRepId
INNER JOIN
dbo.ICO ON dbo.MemberEligibility.ICOId = dbo.ICO.ICOId
INNER JOIN
dbo.WorkerCompTier ON dbo.MemberWorkerCompDetail.TierId = dbo.WorkerCompTier.TierId
GO
MEMBER trigger:
ALTER TRIGGER [dbo].[InsertNewMember]
ON [dbo].[Member]
INSTEAD OF INSERT
AS
BEGIN
SET NOCOUNT ON;
INSERT INTO MemberBasic (FirstName, MiddleInitial, LastName, GenderId, DateOfBirth, Address, Address2, City, State, ZipCode, PhoneNumber, SocialSecurityNumber, DriversLicense, EmployerIdentificationNumber, Notes)
SELECT
FirstName, MiddleInitial, LastName, GenderId, DateOfBirth,
Address, Address2, City, State, ZipCode, PhoneNumber,
SocialSecurityNumber, DriversLicense,
EmployerIdentificationNumber, Notes
FROM
inserted
INNER JOIN
Gender ON Gender.Name = Gender;
INSERT INTO MemberDetail (MemberId, FieldRepId, DateAssigned, CPReceivedOn, CredentialedOn)
SELECT
MemberId, FieldRep.FieldRepId, FieldRepDateAssigned,
CPReceivedOn, CredentialedOn
FROM
inserted
INNER JOIN
FieldRep ON FieldRep.Name = FieldRepName;
INSERT INTO MemberEligibility (MemberId, ICOId, StartDate, EndDate)
SELECT
MemberId, ICOId, EligibilityStartDate, EligibilityEndDate
FROM
inserted
INNER JOIN
ICO ON ICO.Name = ICO;
INSERT INTO MemberWorkerCompDetail (MemberId, AuditDate, ExpirationDate, TierId)
SELECT
MemberId, WorkerCompAuditDate, WorkerCompExpirationDate, TierId
FROM
inserted
INNER JOIN
WorkerCompTier ON WorkerCompTier.Name = WorkerCompTier;
INSERT INTO MemberAttachment (MemberId, Data)
SELECT MemberId, AttachmentData
FROM Member
END
You can do this by using a table variable to hold the newly inserted IDs and all of the data that you're going to insert into the other tables. You need to do this because there's no way from just the first INSERTs data to join back to inserted in such a manner that you can match up the IDENTITY values with the rows that caused them to be generated.
We also have to abuse MERGE since INSERT doesn't let you include anything other than the target table in its OUTPUT clause.
I'm doing this on a toy example but hopefully you can see how to write it for your full table structures.
First, some tables:
create table dbo.Core (
ID int IDENTITY(-71,3) not null,
A varchar(10) not null,
constraint PK_Core PRIMARY KEY (ID)
)
go
create table dbo.Child1 (
ID int IDENTITY(-42,19) not null,
ParentID int not null,
B varchar(10) not null,
constraint PK_Child1 PRIMARY KEY (ID),
constraint FK_Child1_Core FOREIGN KEY (ParentID) references Core(ID)
)
go
create table dbo.Child2 (
ID int IDENTITY(-42,19) not null,
ParentID int not null,
C varchar(10) not null,
constraint PK_Child2 PRIMARY KEY (ID),
constraint FK_Child2_Core FOREIGN KEY (ParentID) references Core(ID)
)
go
And the view:
create view dbo.Together
with schemabinding
as
select
c.ID,
c.A,
c1.B,
c2.C
from
dbo.Core c
inner join
dbo.Child1 c1
on
c.ID = c1.ParentID
inner join
dbo.Child2 c2
on
c.ID = c2.ParentID
go
And finally the trigger:
create trigger Together_T_I
on dbo.Together
instead of insert
as
set nocount on
declare #tmp table (ID int not null, B varchar(10) not null, C varchar(10) not null);
merge into dbo.Core c
using inserted i
on
c.ID = i.ID
when not matched then insert (A) values (i.A)
output
inserted.ID /* NB - This is the output clauses inserted,
not the trigger's inserted so this is now populated */
,i.B,
i.C
into #tmp;
insert into dbo.Child1(ParentID,B)
select ID,B
from #tmp
insert into dbo.Child2(ParentID,C)
select ID,C
from #tmp
(And I would keep something like that comment in there since statements inside triggers that include OUTPUT clauses tend to be quite confusing since there are two inserted tables in play)
(It's also noteworthy that it doesn't really matter what you put in the ON clause of the MERGE, so long as you're sure that it will fail to make a match. You may prefer to have, say, just 1=0 if you think it makes it clearer. I just went cute on the fact that the trigger's inserted.ID will be NULL)
And now we do our insert:
insert into dbo.Together(A,B,C) values ('aaa','bbb','ccc')
go
select * from dbo.Together
And get the result:
ID A B C
----------- ---------- ---------- ----------
-71 aaa bbb ccc
Here is answer to your question "Getting Identity values to use as FK in an INSTEAD OF trigger"
https://dba.stackexchange.com/questions/34258/getting-identity-values-to-use-as-fk-in-an-instead-of-trigger

Select rows that have a specific set of items associated with them through a junction table

Suppose we have the following schema:
CREATE TABLE customers(
id INTEGER PRIMARY KEY,
name TEXT
);
CREATE TABLE items(
id INTEGER PRIMARY KEY,
name TEXT
);
CREATE TABLE customers_items(
customerid INTEGER,
itemid INTEGER,
FOREIGN KEY(customerid) REFERENCES customers(id),
FOREIGN KEY(itemid) REFERENCES items(id)
);
Now we insert some example data:
INSERT INTO customers(name) VALUES ('John');
INSERT INTO customers(name) VALUES ('Jane');
INSERT INTO items(name) VALUES ('duck');
INSERT INTO items(name) VALUES ('cake');
Let's assume that John and Jane have id's of 1 and 2 and duck and cake also have id's of 1 and 2.
Let's give a duck to John and both a duck and a cake to Jane.
INSERT INTO customers_items(customerid, itemid) VALUES (1, 1);
INSERT INTO customers_items(customerid, itemid) VALUES (2, 1);
INSERT INTO customers_items(customerid, itemid) VALUES (2, 2);
Now, what I want to do is to run two types of queries:
Select names of customers who have BOTH a duck and a cake (should return 'Jane' only).
Select names of customers that have a duck and DON'T have a cake (should return 'John' only).
For the two type of queries listed, you could use the EXISTS clause. Below is an example query using the exists clause:
SELECT cust.name
from customers AS cust
WHERE EXISTS (
SELECT 1
FROM items
INNER JOIN customers_items ON items.id = customers_items.itemid
INNER JOIN customers on customers_items.customerid = cust.id
WHERE items.name = 'duck')
AND NOT EXISTS (
SELECT 1
FROM items
INNER JOIN customers_items ON items.id = customers_items.itemid
INNER JOIN customers on customers_items.customerid = cust.id
WHERE items.name = 'cake')
Here is a working example: http://sqlfiddle.com/#!6/3d362/2

SQL Simple SELECT Query

create table Person(
SSN INT,
Name VARCHAR(20),
primary key(SSN)
);
create table Car(
PlateNr INT,
Model VARCHAR(20),
primary key(PlateNr)
);
create table CarOwner(
SSN INT,
PlateNr INT,
primary key(SSN, PlateNR)
foreign key(SSN) references Person (SSN),
foreign key(PlateNr) references Car (PlateNr)
);
Insert into Person(SSN, Name) VALUES ('123456789','Max');
Insert into Person(SSN, Name) VALUES ('123456787','John');
Insert into Person(SSN, Name) VALUES ('123456788','Tom');
Insert into Car(PlateNr, Model) VALUES ('123ABC','Volvo');
Insert into Car(PlateNr, Model) VALUES ('321CBA','Toyota');
Insert into Car(PlateNr, Model) VALUES ('333AAA','Honda');
Insert into CarOwner(SSN, PlateNr) VALUES ('123456789','123ABC');
Insert into CarOwner(SSN, PlateNr) VALUES ('123456787','333AAA');
The problem I'm having is the SELECTE query I wanna make. I wan't to be able to SELECT everything from the Person and wan't the include the PlateNr of the car he's the owner of, an example:
PERSON
---------------------------------
SSN NAME Car
123456789 Max 123ABC
123456787 John 3338AAA
123456788 Tom
----------------------------------
So, I want to be able to show everything from the Person table and display the content of CarOwner aswell if the person is in fact a CarOwner. What I have so far is: "SELECT * from Person, CarOwner WHERE Person.SSN = CarOwner.SSN;". But this obviously results in only showing the person(s) that are CarOwners.
Hope I explained me well enough, Thanks.
Try this:
SELECT p.*, c.*
FROM Person p
LEFT OUTER JOIN CarOwner co
ON p.SSN = co.SSN
LEFT OUTER JOIN Car c
ON co.PlateNr = c.PlateNr
Show SQLFiddle
P.S. I've changed the type of your primary key PlateNr (in varchar and not in int)
select ssn, name, car
from Person p
LEFT OUTER JOIN CarOwner co
ON p.SSN = co.SSN
LEFT OUTER JOIN Car c
ON co.PlateNr = c.PlateNr