While inserting rows into a table, there are times when the requirement is to insert the rows into a table, but if the key already exists, then update the value. In this article, we will be looking into :. We will be looking into all of them with detailed examples but first, let us look into the dataset. Figure 1.
Using the classic insert statement, we will be getting an error, observe the query and the action output message. Notice the query and the action output message.
On running the above query, we get only a warning message and not an error, but nothing gets changed in the table if we see the results. Notice the below two images of the action output message and the table data in figure 1.
Observe the below query with an action output message received after running it. Home SQLTeam. As i said earlier there are two methods of doing this: 1. P1 executes it at time T1 executed update found that row does not exist b. P2 executes it at time T1 executed update found that row does not exist c. Both will try insert and one will fail.
Case 1. Solution 1. Try insert, then on exception of duplicate row, update. Lets try our scenario: Case 1. P1 executes it at time T1 insert will create the row b.
P2 executes it at time T1 insert is attempted, but because of P1 this will wait until P1 comits c. If P1 commits, P2 will detect duplicate and do the update. If P1 rolls back, P2's insert will succeed. P1 executes it at time T1 insert will detect a duplicate b.
P2 executes it at time T1 insert will detect a duplicate c. Both can do the update. Don't think this can't happen; I actually noticied the issue in a high volume environment Saad Ahmad saad. Mladen re: SQL Server: Best way to Update row if exists, Insert if not well exception handling is pretty heavy duty operation Saad Ahmad re: SQL Server: Best way to Update row if exists, Insert if not Isolation levels are not the right solution since the problem is in a high volume scenario where you do not want more isolation.
The following code may work. Viewed 13k times. Need to insert a row if its not exist and update if exists. Improve this question. Dmytro Dmytro 1 1 gold badge 2 2 silver badges 11 11 bronze badges. That syntax is a MySQL quirk. Add a comment. Active Oldest Votes. Improve this answer. EzLo EzLo It's a much more compact solution. Neil B Neil B 2, 1 1 gold badge 9 9 silver badges 21 21 bronze badges.
This is just an example.
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