Updating multiple columns in mysql
As in life, the most important thing is to find a good balance and determine which criteria really matter.If this article was useful to you, you should subscribe to stay current with my upcoming articles. But if there are a large number of rows that require an update, then the overhead of issuing large numbers of UPDATE statements can result in the operation as a whole taking a long time to complete.The traditional advice for improving performance for multiple UPDATE statements is to “prepare” the required query once, and then “execute” the prepared query once for each row requiring an update.In this article I have discussed several ways to use such non-standard extensions in My SQL for performance and convenience. Not only does it potentially make code non-portable, it can encourage mediocrity by teaching bad habits instead of teaching people the “right” way to do things.For example, updating multiple tables in a single statement, or inserting and updating at the same time, are definitely strange and ugly things to do.and we could persuade the database server to apply those updates to the target table?This is in fact entirely possible in many database systems.
If the software must support multiple database backends performance is critical, there’s probably no way to avoid writing different queries for each supported backend.
to allow inserting and updating exactly the desired data.
These features provide a lot of power and flexibility, making My SQL significantly more capable than it otherwise might be.
A requirement arises in many systems to update multiple SQL database rows.
For small numbers of rows requiring updates, it can be adequate to use an UPDATE statement for each row that requires an update.