From the course: Intermediate SQL: Data Reporting and Analysis

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Using MERGE instead of UPDATE/INSERT

Using MERGE instead of UPDATE/INSERT - SQL Tutorial

From the course: Intermediate SQL: Data Reporting and Analysis

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Using MERGE instead of UPDATE/INSERT

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- SQL has been around since the seventies but the merge command was only entered into the SQL standard in 2008. So it's a relative newcomer. Merge does something quite special. It checks whether a record is present, based on a field you specify such as ID. If that record is present, it updates the fields to other fields that you specify. And if the record is not present, it inserts a row. So it's combining a two step process into one. For years, programmers have been checking whether the record is present with select, and then either running an update or insert command on that basis or indeed a delete command, which the merge query can also include. The problem with the two step process is that somebody else might come along and change your database in between the times it takes to execute those two statements. Even if they are only separated by a semicolon and run in the same window, there is still the opportunity for…

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