I have three tables, the first two are used to store information about people.
So how do I add the date to the link the 3 tables?
Trying to practice my school work at home and have no idea how to do this!
Edit: all I can think off would be this SELECT B.Date_of_exams, C.last_name, B.subjects_name
If I understand what you want, you need to join the tables using INNER JOIN like this:
SELECT B.Date_of_exams, C.last_name, B.subjects_name
FROM
entries A
INNER JOIN subjects B
ON A.subjects = B.subjects_id
INNER JOIN students C
ON A.student = C.student_id
Related
I just recently learned about SQL INNER JOIN and I thought of applying it on a project so basically I have three tables
payers
discounts
items
Now I was just wondering if I can return the results from both of the three tables at once using an INNER JOIN with both of the 3 tables or is it only possible with 2 tables?
If it is possible to use an INNER JOIN with more than 2 tables then kindly please guide me on how to do it and if not then tell me how to do it in any other ways possible.
Now this is the query that I currently have which doesn't work as expected:
SELECT *
FROM payers
INNER JOIN discounts AND items
ON payers.id = discounts.id AND ON payers.id = items.id;
You want two joins. The syntax is:
SELECT *
FROM payers p
INNER JOIN discounts d ON d.id = p.id
INNER JOIN items i ON i.id = p.id
Side notes:
you did not show your actual schema, so this uses the join conditions described in your attempt; you might need to review that
table aliases make the query shorter to write and easier to read
SELECT * is generally not good practice; instead, I would recommend enumerating the columns you want in the SELECT clause, and properly aliasing conflicting columns names, if any (here, all three tables have a column called id, which would cause ambiguity in the resultset)
I am trying to make an INNER JOIN statement that will join two tables, the Orders table and the Customer table, these both share the value/key of CustomerID. The Customer table has the information for which state a customer lives in. The Orders table has the information for which customer, according to their customer ID, bought which product. I need to find which products are the top 3 most popular in certain states. Please find the table descriptions images below, so you can understand what I mean.
Orders table:
Customer table:
How can I make this INNER JOIN statement and include the logical operators (and/or) to make this happen?
Thanks!
Try this,
SELECT column_name(s)
FROM Customer
INNER JOIN Order
ON Customer.CustomerID= Order.Customer_ID AND <conditions>;
Inner Join is just only 1 way of joining 2 tables. You can also join these two tables using WHERE closure as follows,
SELECT column_name(s)
FROM Customer c, Order o
WHERE c.CustomerID = o.Customer_ID AND <condition>
I am newish to SQL and Join statements and I am way out of my league at the moment
I currently have 6 Database Tables that are all linked to the main 7th table based on the main tables ID, however all the information in the other 6 tables are looped and so have several displayed results to the one main tables ID.
Is it possible to join them all into one Join Statement so I can have a results so that everyones information from the main table also shows their information from the 6 other linked tables
So basically when they all have the informationed joined I want to be able to Display all information on a webpage
so I was wondering do I need to do multiple JOIN statements or just one Longer one?
I have Included some Images below that explain it visually. See examples 1 and 2
The columns that are highlighted in yellow are looped to have many results:
2. This is the example of how the information is looped into the
database where there are many Race_id sharing to the same inf_id:
Im not so sure how it will look once it has been joined since some of the information is looped into many Id's and not sure if that means it need to duplicate the column or the rows?? any help would be greatly appreciated.
You could use left join eg for the first tables influencer, social, activities
select i.*, s.follower, s.Social_Medial_URL, a.activity, a.result
from influencer i
left join social s on s.inf_id = i.id
left join activities a on a.inf_id = i.id
you can procede yourself adding the left join for the others tables using the same rules
select i.*
, s.follower_count
, s.social_media_url
, a.compete_activity
, a.compete_results
from influencers i
left join inf_other_social s on s.inf_id = i.id
left join inf_compete_activity a on a.inf_id = i.id
LIMIT 0, 25
I think you are confused about primary key and foreign key. the picture you have given is clearly elaborate everything. as per your db diagram the query might be like this...
select * from
Influencer i
Left Join Social s on i.inf_id = s.inf_id
Left Join Owned_Equip o on i.inf_id=o.inf_id
Left Join Ages_Interacted a on i.inf_id = a.inf_id
Left Join Activities ac on i.inf_id = ac.inf_id
Left Join Awards aw on i.inf_id = aw.inf_id
Left Join History h on i.inf_id = h.inf_id
By using this above query you can get all the information of Influencer and related to him (Social,Owned_Equip,Activities,Award etc) whether they exists or not. If you using only "Join" not "Left Join" then you can only find those records which is common for a single influencer to it's related entities/tables which might you say. as an example: say Influencer (id = 1 , suppose name is dan) after inner join we can get only records related to dan ( his social,owned equipments,activites,awards and so on if those tables contains record related to dan record)
I have two tables:- PERSON and DATA. What I want to do is fetch all details from PERSON table and only two columns from DATA table only when PERSON.personId = DATA.personId.
I am using this query:-
SELECT *
FROM PERSON AND SELECT DATA.value, DATA.field
FROM DATA where PERSON.personId = DATA.personId;
But I think this is wrong syntax. Can anyone tell me what is the right syntax for it.
SELECT p.*,d.column1,d.column2
FROM Person p
JOIN Data d
ON p.personId = d.personId
WHERE <Condition>
In this query person with all columns and data with your desire column you can fetch by this query.
Something like this:
select
P.*,
D.value,
D.field
from Person P
join Data D on P.PersonID = D.PersonID
change P.* to the specific columns that you need but P.* will get everything from the Person table.
check this post out LEFT JOIN vs. LEFT OUTER JOIN in SQL Server to learn about JOINS, the diagram is good to understand what the different ones do
Its really easy, Just execute this query:
SELECT
PERSON.*,
DATA.value,
DATA.field
FROM
PERSON INNER JOIN DATA USING (`personId`);
It selects all fields of PERSON + value and field from DATA.
Also it uses personId to join the two tables.
Fill free to ask if you need more info.
You can use join (LEFT JOIN)
SELECT * FROM PERSON LEFT JOIN DATA ON PERSON.personId = DATA.personId
Hope it will help you
Here's the correct syntax for achieving what you've asked for:
SELECT PERSON.column1,PERSON.column2,PERSON.columnN,DATA.value
FROM PERSON
INNER JOIN DATA
ON PERSON.personId = DATA.personId
Line#1: lists the columns that you want to select with references to their parent tables.
Line#2 and 3: are the two tables that you want to select from and join with
Line#4: is the join condition between the two tables (with matching IDs or other information)
I haven't been able to figure out how to make this query work.
I have a table for people and their personal data.
I have a table of let's call it houses
Let's say that the tables have these fields:
PEOPLE
id, code, name, lastname
HOUSES
id, codeowner, codeintermediate, codebuyer, area, numberofrooms
If I have three columns with a relationship with the same table (people) how can I make a LEFT JOIN work?
If owners, intermediates and buyers were separated I would use something like
"SELECT
houses.*,
owners.name AS ownersname,
intermediates.name AS intermediatesname,
buyers.lname AS buyersname
FROM houses
LEFT JOIN owners ON houses.codeowner = owners.code
LEFT JOIN intermediates ON houses.codeintermediate = intermediates.code
LEFT JOIN buyers ON houses.codebuyer = buyers.code
But how can I make this work with a single PEOPLE table? How can I use the aliases and so? Thank you beforehand!
Join the people table 3 times
SELECT
houses.*,
owners.name AS ownersname,
intermediates.name AS intermediatesname,
buyers.name AS buyersname
FROM houses
LEFT JOIN people as owners ON houses.codeowner = owners.code
LEFT JOIN people as intermediates ON houses.codeintermediate = intermediates.code
LEFT JOIN people as buyers ON houses.codebuyer = buyers.code