Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Transact-SQL Statement.

Posted on 1998-12-01
4
Medium Priority
?
253 Views
Last Modified: 2010-03-19
I have the following structure of 3 tables with the key fields shown.
TableA        TableB          TableC
TA_Key <----> TA_Key <------> TA_Key
              TB_Year         TB_Year
with the tables linked as shown.
In order to set up a text file with details from the three
tables I have set up a stored proc with the following statement.
SELECT * from TableA, TableB, TableC
WHERE TableA.TA_Key = @p1 AND TableA.TA_Key = TableB_TA_Key
AND TableA.TA_Key = TableC.TA_Key.

This returns me resultsets perfectly fine except in the
situations where a row exists on TableA and TableB but not
on TableC or some combination of this.
In this situation I would like the resultset to return me
the TableA and TableB rows and the TableC row as blank.
Whats the best way to write my SQL Statement ?.
ED.
0
Comment
Question by:eryan
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
4 Comments
 
LVL 2

Expert Comment

by:odessa
ID: 1092022
Try to use some like "TA_Key = NULL" in this way

SELECT * from TableA, TableB, TableC
WHERE ((TableA.TA_Key = @p1) or (TableA.TA_Key = NULL)) and
      ((TableB.TA_Key = @p1) or (TableB.TA_Key = NULL)) and
      ((TableC.TA_Key = @p1) or (TableC.TA_Key = NULL))
0
 

Author Comment

by:eryan
ID: 1092023
Odessa,
That still only returns me a result set if tablesA,B,C all have
a matching Key.
I.E If there is a TableA row with key = 12
                a TableB row with key = 12, 1998
                a TableC row with key = 12, 1998 its fine
but if the tableC row does not exist, then a blank resultsset
is returned.
ED

0
 
LVL 2

Accepted Solution

by:
tschill120198 earned 280 total points
ID: 1092024
You need to use outer joins to tables B and C...

    select  a.TA_Key,
          b.year,
            c.year
    from    tableA a
            left outer join tableB b on (a.TA_Key = b.TA_Key)
            left outer join tableC c on (a.TA_Key = c.TA_Key)
    where   a.TA_Key = @p1

This will give you back nulls for tables B and C when they don't have a value... if you really want a "blank" you can convert the column in the result
0
 

Author Comment

by:eryan
ID: 1092025
Tschill,
Thanks for that, exactly what I needed.
ED.

0

Featured Post

Enroll in October's Free Course of the Month

Do you work with and analyze data? Enroll in October's Course of the Month for 7+ hours of SQL training, allowing you to quickly and efficiently store or retrieve data. It's free for Premium Members, Team Accounts, and Qualified Experts!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Why is this different from all of the other step by step guides?  Because I make a living as a DBA and not as a writer and I lived through this experience. Defining the name: When I talk to people they say different names on this subject stuff l…
Windocks is an independent port of Docker's open source to Windows.   This article introduces the use of SQL Server in containers, with integrated support of SQL Server database cloning.
Via a live example, show how to extract insert data into a SQL Server database table using the Import/Export option and Bulk Insert.
Viewers will learn how to use the UPDATE and DELETE statements to change or remove existing data from their tables. Make a table: Update a specific column given a specific row using the UPDATE statement: Remove a set of values using the DELETE s…

609 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question