How to Select All Records from One Table That Do Not Exist in Another Table

How to select all records from one table that do not exist in another table?

SELECT t1.name
FROM table1 t1
LEFT JOIN table2 t2 ON t2.name = t1.name
WHERE t2.name IS NULL

Q: What is happening here?

A: Conceptually, we select all rows from table1 and for each row we attempt to find a row in table2 with the same value for the name column. If there is no such row, we just leave the table2 portion of our result empty for that row. Then we constrain our selection by picking only those rows in the result where the matching row does not exist. Finally, We ignore all fields from our result except for the name column (the one we are sure that exists, from table1).

While it may not be the most performant method possible in all cases, it should work in basically every database engine ever that attempts to implement ANSI 92 SQL

Why am I unable to select all records in one table that don't exist in another table?

From what you've shown you could see if a not exists criteria serves the purpose. If this doesn't work as expected then almost certainly there's something different, eg collation, that we don't know about.

select col1
from table_1 t1
where not exists (select * from table_2 t2 where t2.col1 = t1.col1);

How to select all records from one table that do not exist in another table for certain condition in another table?

You want a not exists i.e. select all from Book where not exists a record in BookSeller for the same book and SellerId 1 or 3.

select B.ISBN10
from Book B
where not exists (
select 1
from BookSeller S
where B.ISBN10 = S.ISBN10
and SellerId IN (1, 3)
)

Note - your question title actually gives you the answer :)

Also with regard to your comment about not using sub-queries; you should not restrict your options by premature optimisation as the query engine is usually much better than you might think. I can assure you I have used such a construct on large tables with no issues.

You should always build your queries using the most straightforward logic you can and trust SQL Server to build a good query plan. By trying to optimise yourself you may in fact force a more complex query plan. Of course if you actually do run into performance issues, then its time to dig in an investigate. But you do that scientifically i.e. by measuring the performance of different options using the execution plan.

SQL to find record with a value in one table but not another table

Assuming your IDs do not change in either table so that ID 100 in Address always points to ID 100 in Address_Backup:

  SELECT * 
FROM Address_Backup
WHERE ID NOT IN (SELECT ID FROM Address) AND Code = 'OTHER'

using NOT EXISTS

 SELECT * 
FROM Address_Backup AS B
WHERE NOT EXISTS (SELECT 1 FROM Address WHERE ID = B.ID) AND Code = 'OTHER'

How to select data from the table not exist in another table sql

I think your table table1 and table2 have index on their name column, so you can try this:

SELECT name
FROM table1 t1 LEFT JOIN table2 t2 ON t1.name = t2.name
WHERE t2.id IS NULL

May be id column existed, if not, use t2.name as a replacement for t2.id

Find records from one table which don't exist in another

There's several different ways of doing this, with varying efficiency, depending on how good your query optimiser is, and the relative size of your two tables:

This is the shortest statement, and may be quickest if your phone book is very short:

SELECT  *
FROM Call
WHERE phone_number NOT IN (SELECT phone_number FROM Phone_book)

alternatively (thanks to Alterlife)

SELECT *
FROM Call
WHERE NOT EXISTS
(SELECT *
FROM Phone_book
WHERE Phone_book.phone_number = Call.phone_number)

or (thanks to WOPR)

SELECT * 
FROM Call
LEFT OUTER JOIN Phone_Book
ON (Call.phone_number = Phone_book.phone_number)
WHERE Phone_book.phone_number IS NULL

(ignoring that, as others have said, it's normally best to select just the columns you want, not '*')

How to select all data from one table and records from another table matching data in first selection. All in one query

If you want data from one table and, if it exists, data from another table then why does a simple left outer join not work?

select * from Messages 
left outer join Files on
Messages.message_id = Files.message_id

Find ID which doesn't exist from another table

You can try below.

Using EXCEPT

select OrderID from reference_OrderTable
EXCEPT
select OrderID from OrderTable

using join

select r.OrderID from reference_OrderTable r 
LEFT JOIN OrderTable o ON o.OrderID = r.OrderID
WHERE o.OrderID IS NULL

using sub queries

select OrderID from reference_OrderTable
where OrderID NOT IN (select OrderID from OrderTable)


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