Secondly, it needs to know which columns are to be updated, and the new values for those columns.
Finally, it needs information about which specific rows are to be updated (controlled by the WHERE keyword).
In fact, it is often even recommended that the criteria to be used for the WHERE filter first be tested with a SELECT statement to ensure it does exactly what you intended.
The WHERE keyword is probably the most important part of the statement to remember.
Without a WHERE condition, the update will be applied to every row in the table.
Next we create print Count variable in which we get previous upload/print count of the user and add filescount to it.
Now we need to save new print Count to database so we run UPDATE mysql query and update printcount where userid matches the currently logged in user.
The UPDATE statement requires a few items of information in order to operate.
Firstly, it needs the name of the table that is to be updated.When updating data in a table it is possible to either update specific rows, or to update all the rows in a table.These tasks are achieving using the SQL UPDATE statement combined with the SET and WHERE keywords.To delete the table and its contents use the DROP TABLE SQL statement: In this chapter of My SQL Essentials we explored how to update and delete rows in a table.We have also learned about the importance of using WHERE keyword to control which rows get updated or deleted when the statement is executed.For example, we can easily extend our previous example to update the prod_name and prod_desc columns of our products database table: If an UPDATE statement is designed to update multiple rows, and an error is encountered attempting to update some of those rows, the entire update is canceled and any rows that had been changed are reverted to their original values.