TonyC
TonyC

Reputation: 397

SQL-Server replace empty cells with NULL value

I am using SSIS to move excel data to a temp sql server table and from there to the target table. So my temp table consists of only varchar columns - my target table expects money values for some columns. In my temp table the original excel columns have a formula but leave an empty cell on some rows which is represented by the temp table with an empty cell as well. But when I cast one of these columns to money these originally blank cells become 0,00 in the target column.

Of course that is not what I want, so how can I get NULL values in there? Keeping in mind that it is possible that a wanted 0,00 shows up in one of these columns.

I guess I would need to edit my temp table to turn the empty cells to NULL. Can I do this from within a SSIS package or is there a setting for the table I could use?

thank you.

Upvotes: 3

Views: 20089

Answers (1)

Fedor Hajdu
Fedor Hajdu

Reputation: 4697

For existing data you can write a simple script that updates data to NULL where empty.

UPDATE YourTable SET Column = NULL WHERE Column = ''

For inserts you can use NULLIF function to insert nulls if empty

INSERT INTO YourTable (yourColumn)
SELECT NULLIF(sourceColum, '') FROM SourceTable

Edit: for multiple column updates you need to combine the two solutions and write something like:

UPDATE YourTable SET 
Column1 = NULLIF(Column1, '')
, Column2 = NULLIF(Column2, '') 
WHERE Column1 = '' OR Column2 = '' 

etc

That will update all

Upvotes: 9

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