I have a Competitions results table which holds team member s names and their ranking on one hand On the other hand I need to maintain a table of unique competitors names CREATE TABLE Competitors cName nvarchar 64 primary key Now I have some 200 000 results in the 1st table and when the competitors table is empty I can perform this INSERT INTO Competitors SELECT DISTINCT Name FROM CompResults And the query only takes some 5 seconds to insert about 11 000 names So far this is not a critical application so I can consider truncate the Competitors table once a month when I receive the new competition results with some 10 000 rows But what is the best practice when new results are added with new AND existing competitors I don t want to truncate existing competitors table I need to perform INSERT statement for new competitors only and do nothing if they exists

SQL Server insert if not exists best practice

The Solution to SQL Server insert if not exists best practice is

Semantically you are asking "insert Competitors where doesn't already exist":

INSERT Competitors (cName)
SELECT DISTINCT Name
FROM CompResults cr
WHERE
   NOT EXISTS (SELECT * FROM Competitors c
              WHERE cr.Name = c.cName)

~ Answered on 2011-03-13 09:21:10

SQL Server insert if not exists best practice

The Solution to SQL Server insert if not exists best practice is

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