In practice, you shouldn’t notice database bloat unless you’re using a poorly optimized web host. They can also slow down request processing times within your website, and cause compatibility issues with other plugins. Other plugins simply leave tables behind due to poor coding practices. Some plugins do this so you can retain configured settings if you decide to re-install them. These are tables that contain unused data. Some plugins leave behind “orphaned” database tables. If you’re using WordPress, you’ll be uninstalling plugins at some point. There are a few situations where you might need to use MySQL to delete a table. Ready to delete a table.but not sure where to start? □ This guide is for you □ Click to Tweet Why Delete a Table in MySQL If you accidentally delete a critical table, you’ll need to restore the entire database (or website) from a backup. This is because WordPress constantly makes requests to the database to pull the data that it shows to users. For dynamic websites, such as those built with WordPress, deleting the wrong table can break the entire site. It’s a well-known fact among developers that deleting tables in a database can be a risky process. When you delete a table, all of its rows will disappear from the database: MySQL table drop We started to go down this road over here but maybe it is not required.“Dropping a table” in MySQL refers to the SQL command that enables you to delete a table within a database. ![]() Only deleting duplicates edit, added within the range of ShiftStartDate specified requires additional information. I was just showing an alternate to using DELETE-JOIN that might be a little more expressive. What did you want to know? If you were thinking this MERGE would de-duplicate the range, it won't. Thanks for this awesome approach, can you please help with the SELECT (you mentioned in quote) query for below query ? With the query written this way I can highlight the SELECT statement in the USING clause to see what would be deleted without changing the query or carrying additional debug-comments in the code: JOIN dbo.BC_ShiftSummary B ON A.SS_ID = B.SS_ID After working with it more and more I find the MERGE syntax to be quite intuitive and a little easier to use when debugging (my opinion). ![]() One other option I thought I would share. It is always interpreted the same way independent of the language settings.Ī DELETE-JOIN will work well. ![]() It's enough to have different default language set for a user or a connection. When using the format "YYYY-MM-DD" the date can be interpreted in the us-english oder british-english(or german) format, switching the day and the month. ![]() You should do that too in future scripts. When sure the command is doing what you want just replace the ROLLBACK with a COMMIT and the delete operation is finally executed.Īs you may have seen I removed the "-" from the datetime-strings. When using the OUTPUT-command you can even see which records would have been deleted: This way you get the number of deleted records without actually deleting the records. If ure are still not sure use a BEGIN TRANSACTION at the beginning and a ROLLBACK transaction at the end of the command. Then remove the order-by-clause and that's it. You just need to replace the select-command with an delete-command, followed by the table to delete the data from.
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