Writing sql queries from multiple tables

I could use some help writing a SQL query. I'm trying to display some data from one table but the data I need depends on a value from a different table. I'm pretty new to this so I will try to explain this the best I can:

I have an Orders table with a ShipCity and OrderId columns. I would like to get the OrderId value from Orders where ShipCity = Caracas. using those distinct OrderId values, I 开发者_Go百科would like to query a different table called Order Details where [Order Details].[OrderId] = [Orders].[OrderId] (= to 'Caracas').

I hope that made sense. where I'm getting stuck is I'm sure that I will either need to create some variables or a temporary table to store these values and I don't have any experience with these things yet. I'd appreciate any help. also, these are tables in the Northwind sample database if that helps. below is a dummy sample of what I'm trying to do.

Select OrderId
FROM [Orders]
WHERE ShipCity = 'Caracas'

Select OrderId
FROM [Order Details]
WHERE OrderId = (Orders.ShipCity = 'Caracas')

here's another way of looking at it:

SELECT OrderId
FROM [Order Details]
WHERE OrderId = [Orders].ShipCity = 'Caracas'

You want to use an INNER JOIN

SELECT [Order Details].*
FROM [Order Details]
INNER JOIN [Orders] ON [Orders].OrderId = [Order Details].OrderId
WHERE [Orders].ShipCity = 'Caracas'

More information about joins can be found in the Wikipedia entry or here.

you use a JOIN clause to combine data from two or more tables. Something like this, although you should double check the syntax

select * 
from [Orders] o
join [Order Details] od on o.orderid = od.orderid
where o.shipcity = 'Caracas'

You need to join the two tables:

SELECT DISTINCT o.OrderId
FROM Orders o INNER JOIN [Order Details] od ON o.OrderId = od.OrderId
WHERE o.ShipCity = 'Caracas'

...but why do you need the Order Details table in the query?

How about doing with SubQuery method?

SELECT OrderId
FROM [Order Details]
WHERE (OrderId IN SELECT OrderId FROM Orders WHERE ShipCity = 'Caracas')