How to fill null values of a column with the values of the same row but different column (sql server-CodePudding

I have a table and want to "copy" the values of column findoc and insert them in the rows of column findocs which have null values.

table

CodePudding user response：

You can use COALESCE() to take the first non-NULL value:

UPDATE dbo.tablename SET findocs = COALESCE(findocs, findoc);

Though a more efficient way would be to filter:

UPDATE dbo.tablename SET findocs = findoc 
  WHERE findocs IS NULL AND findoc IS NOT NULL;

CodePudding user response：

You can use coalesce() in a query:

select coalesce(finddocs, finddoc) sa finddocs, finddoc, sum
from t;

Or to change the values using update:

update t
    set finddocs = finddoc
    where finddocs is null;