MySQL非函数：探索不一样的技术（mysql非函数）
MySQL is a widely-used relational database. It has advanced features such as high speed, reliability and flexibility. However, most developers tend to focus on the functions of the database when using it, and often overlook its non-function features. In this article, I will discuss the use of two non-function features of MySQL: stored routines and triggers.
MySQL stored routines are written in a special language and are usually stored in the database, but not as part of the data. A stored procedure can accept parameters and return multiple values. It is designed to optimize the execution of repeated tasks, saving time and making life easier for the developer when a task needs to be repeated. For example, a stored procedure can be defined to perform a query and return the result set. Stored routines can also be used to control access to data, allowing several users to work with data in different ways, while ensuring that one user cannot access data that another user has not made available.
MySQL triggers are database-operation events that trigger an action. These events can be either data modifications or user operations. For example, data modifications may include when a record is inserted or modified, while user operations may include when a user logs in or out of the database. Triggers can be used to enforce certain rules, such as to ensure data integrity or to restrict access to certain data. For example, a trigger can be used to limit the number of times a user can update a given record, or to prevent two users from changing the same record at the same time.
These two features of MySQL can be used together to create powerful and robust applications. For example, a trigger could be used to ensure that data is only modified if it is within certain parameters, such as in a predetermined range. A stored procedure could then be used to verify the data and send an email to the appropriate personnel if the data is outside of the permitted range.
By understanding and making use of the non-function features of MySQL, developers can create applications that are more efficient, secure, and effective. Stored routines and triggers can significantly reduce the amount of coding required, while also improving the security of the application. A few examples of the code necessary to use these features are:
Stored Procedure:
CREATE PROCEDURE `check_range` (in_value int)
BEGIN
IF in_value > 0 AND in_value
— Do something…
END IF;
END;
Trigger:
CREATE TRIGGER `range_check`
BEFORE INSERT ON `my_table`
FOR EACH ROW
EXECUTE PROCEDURE `check_range` (NEW.value);
By taking advantage of the non-function features of MySQL, developers can create applications that are more robust and efficient. These features can simplify the development process, reduce coding time, and improve security.
