sql server - Will SQL update a record if the new values are the same? -


will sql update record if there no change record?

for examople, more efficient replace 

update table mytable  set col1 = isnull(col1,'') ... set col100 = isnull(col30,'')

with

update table mytable  set col1 = isnull(col1,'') ... set col100 = isnull(col30,'')  col1 null or ... col30 null

yes, attempt overwrite.


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