Summary
We started the chapter with a brief discussion about the UPDATE statement used to change data in tables rather than to fetch data. We introduced the syntax of the UPDATE statement and explained a simple example to update one column in all the rows in a table using an expression.
Next we showed an example of how to use the WHERE clause to filter the rows you are updating. We also showed you how to construct a SELECT query first to verify that you’ll be updating the correct rows, and we showed you how to map the clauses in your SELECT query into the UPDATE statement you need. Next we explained the importance of transactions and how you can use them to protect against errors or to ensure that either all changes or no changes are made to ...
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