Hi all so im stuck on this sql query question: write an sql statement that displays details of session (id and date) that shows crime movies. You must use join to obtain the answer.
I have a table for session with an id column and a date column and i have a movie table that has an moviegenre column with 'crime' under it. I was wondering how i could construct this. I found an example of one:
Select orders.orderid,
customers.customername,
orders.orderdate
from orders
inner join customers
on orders.customerid = customers.customerid;
from this site, but am unsure on how to use this so help answer my question. Also is there a way of doing is problem with using a sub query instead
thank you!
Select s.id,
s.date,
from Session s
inner join Movie m
on m.commoncol = s.commomcol
where m.MovieGenre like 'crime';
commomcol represents the mutual column between the tables. Name of the commoncol can be different in both tables.
Hope it helps!!
Related
I have two tables. The first one is for sales (name's table is 'ventas') and the other one, for detailed articles by sale (the name is 'ventaArticulos'). Basically, the last one contains all the articles that were sold.
Those are related by the columns ventas.id_venta and ventaArticulos.id_ventaArticulo
Basically, the idea is to make an SQL SELECT for the first table (ventas) for example, getting the columns 'fecha' and 'importe' but also, perform a 'count' with the total of registers that are in the second table related by sale. (ventas.id_venta and ventaArticulos.id_ventaArticulo)
hope to be clear enough and can help me!
SQL to try to clarify (Obviously it doesn't work):
SELECT ventas.fecha, ventas.importe, count(ventaArticulos.id_codigoArt)
FROM ventas JOIN
ventaArticulos
ON ventaArticulos.id_ventaArticulo = ventas.id_venta
Thanks!
I would recommend to use table alise that could be easier to follow & you forgot to include GROUP BY Clause
SELECT v.fecha, v.importe, count(va.id_codigoArt) counts
FROM ventas v -- Use alise v entire the query instead of table_name
INNER JOIN ventaArticulos va ON va.id_ventaArticulo = v.id_venta
GROUP BY v.fecha, v.importe;
SELECT v1.fecha, v1.importe, count(v2.id_codigoArt)
FROM ventas v1 , ventaArticulos v2
where v1.id_ventaArticulo= v2.id_venta
group by v1.fecha, v1.importe
having count(*) > 1
My SQL statements are not returning any results. I am using the table that are on the www.w3schools.com web site. I want to have all of the customer IDS in my Customers table match all of the CustomerIDS in the Orders table. The SQL statement works that it goes through the table and checks every CustomerID to every Orders.CustomersID and when it finds a match doesn't it return that record.
Question: Why does the SQL not return the row when both customerIDS are equal because there are values that will return true?
SQL Statement:
SELECT * FROM Customers WHERE Customers.CustomersID = Orders.CustomersID;
One last thought: What is the best free SQL database that can be downloaded without a lot of hassle for home use?
Try this:
SELECT Customers.*
FROM Customers
JOIN Orders ON Customers.CustomerID = Orders.CustomerID;
If you just want customers that have orders then use:
SELECT *
FROM Customers
WHERE CustomerID IN
(SELECT CustomerID FROM Orders)
If you use a JOIN you may get multiple records per customer (if the customer has multiple orders). You can solve that with DISTINCT but IMHO a IN clause is cleaner (and likely faster)
You need a query like this: SELECT *
FROM Customers c
INNER JOIN Orders o on c.CustomerID = o.CustomerID;
w3schools is a very bad resource.
Selecting the best database is a bad question for stackoverflow. But the answer is PostgreSQL. (And lots of other DBMSs would fit the bill for you as well.)
I am trying to understand the JOIN command from w3schools tutorial and there is an example.
Can you please "translate" it to me what exactly it does? I already know what do the dots do, but INNER JOIN, ON and so on messed me up?
SELECT Orders.OrderID, Customers.CustomerName, Orders.OrderDate
FROM Orders
INNER JOIN Customers
ON Orders.CustomerID=Customers.CustomerID;
And does it creates a new table in my SQL database or it just creates (lets call it..) "virtual" table which I can use it in the moment
The dot notation here signifies the column of a table.
Table.Column
So the SELECT is retrieving the columns specified from each table.
JOIN matches the tables based on the condition that appears after ON
this queries joins customers to orders based the condition of having the same CustomerID.
For more on joins check out http://www.codinghorror.com/blog/2007/10/a-visual-explanation-of-sql-joins.html
Perhaps the first thing to understand is the "dot notation." When you see a value like Orders.CustomerID SQL will read that to mean the CustomerID column within the Orders table.
The INNER JOIN is looking for an exact match for the records you specify with the ON clause...
So, in this example, SQL will first find all the records in the Orders table which have a CustomerID that matches the CustomerID found in the Customers table.
Then, it will look to the SELECT clause and show you the OrderID (from the Orders table), the CustomerName (from the Customers table) and the OrderDate from the Orders table.
If you're using SQL Server Management Studio (SSMS) or some other similar tool, it should display your results - kindof like a virtual table... but it doesn't actually create a table.
Hope that helps,
Russell
There are INNER AND OUTER JOINS. I think this post sums up those differences well.
What is the difference between "INNER JOIN" and "OUTER JOIN"?
As far as the concept itself you are 'joining' the tables by finding things in common between them based on a shared value in each. If you have ever done a vlookup with Microsoft Excel then you are familiar with this concept. In the query you've posted you are selecting values from both the Orders and Customers table. You can tell which table you are selecting values from by the prefix Orders. or Customers. You can then tell which column by the value following the dot i.e. OrderID, CustomerName, OrderDate.
The way the query knows to pull a conjoined field is if the CustomerID field matches.
So step by step
You are selecting
SELECT Orders.OrderID, Customers.CustomerName, Orders.OrderDate
From the table Orders
FROM Orders
You wish to pull corresponding values from Customers. There are numerous join methods and logic that goes with each but you have chosen INNER JOIN explained in the link above.
INNER JOIN Customers
The criteria for joining is CustomerID
ON Orders.CustomerID=Customers.CustomerID;
To use an approximate Excel Vlookup analogy
The Lookup_value is CustomerID
The Table array is ORDERS
The range lookup is the type of join you are performing
SELECT statement returns data, it doesn't create any table not even virtual table whatsoever (if you see any table after executing SELECT statement, thats just a way the returned data presented). Create and modify table done using DDL (Data Definition Language) statements when SELECT is one of DML (Data Manipulation Language) [reference].
Join statement explained very well here, from basic use to more advance with illustration.
Consider the two tables' schema:
1) Person(name varchar(100),income int)
2) IncomeGroups(incomeGroupName varchar(100), minIncome int, maxIncome int)
I was stumbled while developing a sql query for fetching Person Names with their IncomeGroupNames based on their income.
I am trying to accomplish something like (Name,IncomeGroupName).
Is it even possible? I'll be really glad if anyone can guide me in this.
SELECT a.Name, b.IncomeGroupName
FROM Person a
INNER JOIN IncomeGroups b
ON a.income BETWEEN b.minIncome AND b.maxIncome
To further gain more knowledge about joins, kindly visit the link below:
Visual Representation of SQL Joins
You can use the following query which joins the tables:
select p.name,
i.incomeGroupName
from person p
inner join incomegroups i
on p.income >= i.minIncome
and p.income <= i.maxIncome;
See SQL Fiddle with Demo
This joins the tables based on the range that the person's income falls in.
i hava a set of following tables
customer(cus_id,cus_name);
jointAccount(cus_id,acc_number,relationship);
account(acc_number,cus_id)
now i want to create a select statement to list all the jointAccounts,
it should included the both customer name, and relationship.
I have no idea how to retrieve both different user name, is that possible to do this?
Generally speaking, yes. I'm assuming you mean you want to get customer info for both sides of the joint account per your jointAccount table. Not sure what database you're using so this answer is assuming MySQL.
You can join on the same table twice in a single SQL query. I'm assuming you have not yet created your tables, as you have cus_id listed twice in the jointAccount table. Typically these would be something like cus_id1 and cus_id2, which I've used in my sample query below.
Example:
SELECT c1.cus_id AS cust1_id, c1.cus_name AS cust1_name
, c2.cus_id AS cust2_id, c2.cus_name AS cust2_name, j.relationship
FROM customer c1
INNER JOIN jointAccount j
ON c1.cus_id = j.cus_id1
, customer c2
INNER JOIN jointAccount j
ON c2.cus_id = j.cus_id2
I haven't tested this but that's the general idea.
try this query:
SELECT * FROM jointAccount a LEFT JOIN customer c ON a.cus_id = c.cus_id;
just replace the * with the name of the columns you need.