update records where null from subquery
I have been tryin开发者_运维百科g to get this query to work for the longest and I figure maybe I am not looking at it right. Basically I have records in a table where I am trying to locate where their is data conflicts. Example I have a field that is not a primary key, but I want to find all occurrences where the other columns data are not the same example: So basically if I have two johns and they both have different addresses I want to update my table to make them have the same, even if one John has a null address. I came up with
UPDATE Table
SET Address =Address
SELECT * FROM Table WHERE Address != Address
but this doesnt seem to work
UPDATE t1
SET address = t2.address
FROM YourTable t1
INNER JOIN YourTable t2
ON t1.Name = t2.Name
WHERE t1.PrimaryId <> t2.PrimaryId
AND t1.address IS NULL
AND t2.address IS NOT NULL
Assuming you want to update Table2 with Table1 values and that there exists a column called ID
on both tables that links the data:
UPDATE t2
SET t2.Address = t1.Address
FROM Table2 as t2
INNER JOIN table1 t1
ON t1.Id = t2.Id
UPDATE:
Based on your comment, if you only want to update the null values in table2 then use this:
UPDATE t2
SET t2.Address = t1.Address
FROM Table2 as t2
INNER JOIN table1 t1
ON t1.Id = t2.Id
WHERE t2.Address is null
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