Equivalent of MySQL ON DUPLICATE KEY UPDATE in Sql Server

You are basically looking for an Insert or Update pattern sometimes referred to as an Upsert.

I recommend this: Insert or Update pattern for Sql Server - Sam Saffron

For a procedure that will be dealing with single rows, either these transactions would work well:

Sam Saffron's First Solution (Adapted for this schema):

begin tranif exists (  select *     from mytable with (updlock,serializable)     where col_a = @val_a      and col_b = @val_b      and col_c = @val_c  )  begin    update mytable      set col_d = @val_d      where col_a = @val_a        and col_b = @val_b        and col_c = @val_c;  endelse  begin    insert into mytable (col_a, col_b, col_c, col_d)      values (@val_a, @val_b, @val_c, @val_d);  endcommit tran

Sam Saffron's Second Solution (Adapted for this schema):

begin tran  update mytable with (serializable)    set col_d = @val_d      where col_a = @val_a        and col_b = @val_b        and col_c = @val_c;  if @@rowcount = 0    begin        insert into mytable (col_a, col_b, col_c, col_d)          values (@val_a, @val_b, @val_c, @val_d);     endcommit tran

Even with a creative use of IGNORE_DUP_KEY, you'd still be stuck having to use an insert/update block or a merge statement.

• A creative use of IGNORE_DUP_KEY - Paul White @Sql_Kiwi

update mytable  set col_d = 'val_d'  where col_a = 'val_a'    and col_b = 'val_b'    and col_c = 'val_c';insert into mytable (col_a, col_b, col_c, col_d)  select 'val_a','val_b', 'val_c', 'val_d'  where not exists (select *     from mytable with (serializable)     where col_a = 'val_a'      and col_b = 'val_b'      and col_c = 'val_c'      );

The Merge answer provided by Spock should do what you want.

Merge isn't necessarily recommended. I use it, but I'd never admit that to @AaronBertrand.

• Use Caution with SQL Server's MERGE Statement - Aaron Bertrand

• Can I optimize this merge statement - Aaron Bertrand

• If you are using indexed views and MERGE, please read this! - Aaron Bertrand

• An Interesting MERGE Bug - Paul White

• UPSERT Race Condition With Merge

Try this... I've added comments to try and explain what happens where in a SQL Merge statement.Source : MSDN : Merge Statement

The Merge Statement is different to the ON DUPLICATE KEY UPDATE statement in that you can tell it what columns to use for the merge.

CREATE TABLE #mytable(COL_A VARCHAR(10), COL_B VARCHAR(10), COL_C VARCHAR(10), COL_D VARCHAR(10))INSERT INTO #mytable VALUES('1','0.1', '0.2', '0.3'); --<These are the values we'll be updatingSELECT * FROM #mytable --< Starting values (1 row)    MERGE #mytable AS target --< This is the target we want to merge into    USING ( --< This is the source of your merge. Can me any select statement        SELECT '1' AS VAL_A,'1.1' AS VAL_B, '1.2' AS VAL_C, '1.3' AS VAL_D --<These are the values we'll use for the update. (Assuming column COL_A = '1' = Primary Key)        UNION        SELECT '2' AS VAL_A,'2.1' AS VAL_B, '2.2' AS VAL_C, '2.3' AS VAL_D) --<These values will be inserted (cause no COL_A = '2' exists)        AS source (VAL_A, VAL_B, VAL_C, VAL_D) --< Column Names of our virtual "Source" table    ON (target.COL_A = source.VAL_A) --< This is what we'll use to find a match "JOIN source on Target" using the Primary Key    WHEN MATCHED THEN --< This is what we'll do WHEN we find a match, in your example, UPDATE COL_D = VALUES(COL_D);        UPDATE SET            target.COL_B = source.VAL_B,            target.COL_C = source.VAL_C,            target.COL_D = source.VAL_D    WHEN NOT MATCHED THEN --< This is what we'll do when we didn't find a match    INSERT (COL_A, COL_B, COL_C, COL_D)    VALUES (source.VAL_A, source.VAL_B, source.VAL_C, source.VAL_D)    --OUTPUT deleted.*, $action, inserted.* --< Uncomment this if you want a summary of what was inserted on updated.    --INTO #Output  --< Uncomment this if you want the results to be stored in another table. NOTE* The table must exists    ;SELECT * FROM #mytable --< Ending values (2 row, 1 new, 1 updated)

Hope that helps

You can simulate a near identitical behaviour using an INSTEAD OF TRIGGER:

CREATE TRIGGER tMyTable ON MyTableINSTEAD OF INSERTAS    BEGIN        SET NOCOUNT ON;        SELECT i.COL_A, i.COL_B, i.COL_C, i.COL_D,             CASE WHEN mt.COL_D IS NULL THEN 0 ELSE 1 END AS KeyExists             INTO #tmpMyTable            FROM INSERTED i            LEFT JOIN MyTable mt            ON i.COL_D = mt.COL_D;        INSERT INTO MyTable(COL_A, COL_B, COL_C, COL_D)            SELECT COL_A, COL_B, COL_C, COL_D                FROM #tmpMyTable                WHERE KeyExists = 0;        UPDATE mt            SET mt.COL_A = t.COL_A, mt.COL_B = t.COL_B, mt.COL_C = t.COL_C            FROM MyTable mt                 INNER JOIN #tmpMyTable t                 ON mt.COL_D = t.COL_D AND t.KeyExists = 1;    END;

SqlFiddle here

How it works

• We first project a list of all rows being attempted to be inserted into the table into a #temp table, noting which of those ARE already in the underlying table via a LEFT OUTER JOIN on the key column(s) COL_D which detect the duplication criteria.
• We then need to repeat the actual work of an INSERT statement, by inserting those rows which are not already in the table (because of the INSTEAD OF, we have removed the responsibility of insertion from the engine and need to do this ourselves).
• Finally, we update all non-key columns in the matched rows with the newly 'inserted' data.

Salient Points

• It works under the covers, i.e. any insert into the table while the trigger is enabled will be subject to the trigger (e.g. Application ORM, other stored procedures etc). The caller will generally be UNAWARE that the INSTEAD OF trigger is in place.
• There must be a key of sorts to detect the duplicate criterion (natural or surrogate). I've assumed COL_D in this case, but it could be a composite key. (Key but cannot be IDENTITY for obvious reasons, since the client wouldn't be inserting an Identity)
• The trigger works for both single and multiple row INSERTS

NB

• The standard disclaimers with triggers apply, and more so with INSTEAD OF triggers - as this can cause surprising changes in observable behaviour of Sql Server, such as this - even well intended INSTEAD OF triggers can cause hours of wasted effort and frustration for developers and DBA's who are not aware of their presence on your table.
• This will affect ALL inserts into the table. Not just yours.