Update statement - using substring

try

UPDATE    tbldata
SET            data   = substring(data,1,3) + (SELECT     tblEx.[4KD]
                           FROM         tblEx INNER JOIN
                                                  tblDa ON tblEx.ID = SUBSTRING(tblDa.Data, 1, 3)) + substring(data,7,len(data)-7)

please try the following syntax:

UPDATE    tbldata
SET    data = tblEx.[4KD]
FROM  tblData        
INNER JOIN tblEx
  ON tblEx.ID = SUBSTRING(tblDa.Data, 1, 3))

angelll, yours had a syntax error.
appari, yours worked, almost. :) Here is what is going on. It updated both records in tbldata. In other words, I have two records in tblData that look like this...

101000ABC
202000DEF
 
And then in tblEx I have one record right now with an ID of 101. So...in this particular case it should have only updated the record starting with 101. Thoughts?

sorry, a ) too much at the end

UPDATE    tbldata
SET    data = tblEx.[4KD]
FROM  tblData        
INNER JOIN tblEx
  ON tblEx.ID = SUBSTRING(tblData.Data, 1, 3)

angelll, that is not what I'm looking for. Running that query replaces the data completely, not just the characters 4,3.

appari query does this and works, except for the issue I mentioned before about it updating all records.

ok:

UPDATE    tbldata
SET    data   = substring(data,1,3) + tblEx.[4KD]  + substring(data,7,len(data)-7)
FROM  tblData        
INNER JOIN tblEx
  ON tblEx.ID = SUBSTRING(tblData.Data, 1, 3)

angelll, that worked and I will award the points to you, but before I do may I ask one more question? How would update two parts of the string in tblData. Right now it is updating only the "x's" in this example here... 101XXXABC But what if I wanted to update it like this... 101XXXXXX Make sense?

In other words, I was trying something that like...

UPDATE    tbldata
SET    data   = substring(data,1,3) + tblEx.[4KDI]  + substring(data,7,len(data)-6),
SET    data   = substring(data,1,3) + tblEx.[STT]  + substring(data,7,len(data)-6)
FROM  tblData  
INNER JOIN tblEx
  ON tblEx.ID = SUBSTRING(tblData.Data, 1, 3)

But that did not quite work.

updating 2 parts is of course possible, but not sure what you mean exactly?
your explanation does not match the syntax try.
please retry to formulate the explanation...

Currently in tblData my string looks like this...

101000ABC

At this point with your previous solution the "000" is being updated with the 4KD data in tblEx. I am now asking how you would also update the "ABC" data with the STT data in tblEx.

Is that clear?

that is exactly right.

may i ask you what this portion means - substring(data,10,len(data)-9)

that gets the characters from position 10 to the end...