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Delete all records from all tables - conditionally

Posted on 2014-12-17
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Last Modified: 2014-12-22
Hi,

In my SQL Server database I have numerous tables.
Some tables (NOT ALL) have a boolean (bit) field called "IsVerwijderd".

I want to delete all records from all tables inside the database where field "IsVerwijderd" is present and is set to TRUE.

Does anybody have a solution for this?
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Question by:Delphiwizard
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6 Comments
 
LVL 33

Expert Comment

by:ste5an
ID: 40504561
CAVEAT: Make a backup first!

EXECUTE sp_msforeachtable 'DELETE FROM ? WHERE IsVerwijderd = 1;';

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Accepted Solution

by:
Vitor Montalvão earned 500 total points
ID: 40504629
Try this script:
DECLARE @CommDEL NVARCHAR(MAX)=N''

SELECT @CommDEL = @CommDEL + N'DELETE FROM ' + SCHEMA_NAME(o.schema_id) + '.' + o.name + ' WHERE IsVerwijderd=1;' + CHAR(13) + CHAR(10) 
FROM sys.objects o
	INNER JOIN sys.columns c ON c.object_id=o.object_id
WHERE o.object_id > 255 AND o.type='U' AND c.name='IsVerwijderd'

EXEC sp_executesql @CommDEL 

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Author Comment

by:Delphiwizard
ID: 40504645
@ste5an: Your solution does do the job, but it's not very clean.
As there are tables that do not contain field IsVerwijderd, executing this code will generate numerous errormessages.
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LVL 47

Expert Comment

by:Vitor Montalvão
ID: 40504651
As there are tables that do not contain field IsVerwijderd, executing this code will generate numerous errormessages.
That's why I wrote the script I posted. Only runs the delete command on tables that has the field.
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LVL 33

Expert Comment

by:ste5an
ID: 40504684
You didn't ask for a clean version... There can be always errors caused by triggers or permissions or referential integrity.

The only clean solution is to script a DELETE per table without dynamic SQL. In the correct order regarding to FK relationships and containing the necessary conditions to avoid triggers or permission errors.

Or in simple  words: There is no general clean solution.
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Author Closing Comment

by:Delphiwizard
ID: 40512788
This works fine for me. Thank you.
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