Update one table based on another table and the Date column

Hello Experts,

I have two SQL Tables that look like this:

Tbl_1:

Date    Type    Num
1/20      A        10
1/20      B        13
1/21      A        16
1/21      C        11
1/21      D        22


Tbl_2:
Date    Type    NumAdjust
1/20      A        -3
1/20      B        4
1/21      D        2

I would like to update Tbl 1 using the values in Tbl 2 so that Tbl_1 now looks like this:.

Tbl_1 updated
Date    Type    Num
1/20      A        7
1/20      B       17
1/21      A       16
1/21      C        11
1/21      D        24

I am unsure of the TSQL syntax to do this but think it must be similar to this:
Update Tbl_1
Set Tbl_1.Num = Tbl_1.Num + Tbl_2. NumAdjust
On Tbl_1.Date = Tble_2.Date and Tbl_1.Type = Tbl_2.Type

Does anyone know how to do this?

Thanks!
SaxitalisAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

John_VidmarCommented:
UPDATE	a
SET	Num	=	a.Num + b.NumAdjust
FROM	Tbl_1	a
JOIN	Tbl_2	b	ON	a.Date = b.Date
			AND	a.Type = b.Type

Open in new window

0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
JR2003Commented:
With SQL Server you can use a FROM in your UPDATE statement. To do it you write a SELECT query that returns the data as you want it then just delete the SELECT and add an UPDATE of the alias used in the FROM clause:
Step 1
SELECT T1.Type,
       T1.Num = T1.Num + T2 NumAdjust 
  FROM Tbl_1 T1
 INNER JOIN Tble_2 T2
         ON T2.Type = T1.Type

Open in new window


Step 2:
Then simply turn it into an UPDATE:
UPDATE T1
   SET T1.Num = T1.Num + T2 NumAdjust 
  FROM Tbl_1 T1
 INNER JOIN Tble_2 T2
         ON T2.Type = T1.Type

Open in new window

0
SaxitalisAuthor Commented:
Mr. John Vidmar,

When I run your code:

UPDATE      a
SET      Num      =      a.Num + b.NumAdjust
FROM      Tbl_1      a
JOIN      Tbl_2      b      ON      a.Date = b.Date
                  AND      a.Type = b.Type


I get this error:

Msg 295, Level 16, State 3, Line 1
Conversion failed when converting character string to smalldatetime data type.

Do I need to explicitly Convert Datatypes here??

Thanks,
John (saxitalis)
0
JR2003Commented:
Sounds like you have the Date column on one table defined as a varchar and on the other table as a smalldatetime.
You will need to to a CONVERT so that SQL server will be able to compare the two together.
0
SaxitalisAuthor Commented:
That was it - Thanks!
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft SQL Server 2005

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.