MySQL works on tables, making it easy to store related data. While MySQL views provide an easy way to organize this data in various tables that you can join using logical rules.
Once you start writing queries, their complexity goes on increasing. So, accommodating all the changes in the original table may become a difficult task.
With views, you can easily make changes in the data of a table without changing its original form.
Moreover, if you make changes in the base table, they will automatically reflect in all the views, though the reverse might not always be true.
MySQL views are virtual tables made using SQL queries capable of presenting data from the relevant tables. Further, you can also create views using queries that join one or more tables.
Handling MySQL Views
It is important to know how views work before deciding you need them or not! Let us have a look at how can you create, update or drop views using query statements. Here are some easy ways to execute these actions
Creating a view:Views are becoming popular among the developers and for all the right reasons. They are time-saving and are easy to create. All you need is a base table and then use these statements to easily create a view:
CREATE VIEW view_name AS
SELECT column1, column2, …
Updating Views: Needless to say, you will also have to make changes in the views you create. You can do this using the query statements CREATE OR REPLACE VIEW. The best part is that you can also add conditions to the statements like:
CREATE OR REPLACE VIEW view_name AS
SELECT column1, column2, …
Dropping Views: After you have created a view, you may also sometimes have to delete it. You can do this by using the DROPVIEW statement. Simply use DROP VIEW view_name to delete.
When Should I Use MYSQL Views?
There is never a wrong time do to the right thing. So technically speaking, if you know how to use the MySQL views the right way, you don’t have to think twice before using them. There are numerous ways in which the Mysql views can be helpful for you. Here are a few of them:
Create a Database View
MySQL makes it easy to create a database view that presents data depending on the queries. It also populates data from the original database.
Alter a Database
Along with creating a database, you can also easily make changes in the database with MySQL views. You get the freedom to add or remove columns and rows, making them customisable.
You can execute update and delete commands in the views. The best part is that they are time-saving, as any changes you make will also reflect in the base table.
Be careful that an updatable view can never be based on a non-updatable view. Also, you can not update a view using the TEMPTABLE algorithm. All the updatable views are created with a table that has a primary key column.
Benefits of MySQL Views
We are sure that by now you know Views and also want to execute some complex functions with them. Though, you may know other ways to do that too. But here are a few key points that make MySql views the go-to choice of the developers.
Make data retrieval easy– They simplify the complex SQL queries. So much that they can be understood even by a layman.
Lessens complications– Joins in MySQL Views make changes easier, even for people with no technical knowledge.
Data aggregates– You can also use it to show the aggregated data you are looking for and hide the detailed information.
Security– They add more security to data as you can create a view of the base table that will only show the permissible fields.
When Not to Use MySQL Views?
Nothing in the world comes without pros and cons and MYSQL views are no exception to it. Views can do a lot and save your precious time but they also come with some downsides.
So if you are planning on any of the following functions, MySQL views might not be the right choice for you.
But don’t forget that these depend on how efficiently you use them.
- DML statements– Yes, this is true! You can not make DMLs in MySQL views since you are not working on tables but its virtual form. Though you can make some simple DMLs that depend on the base table, views do not support complex DML.
- Temporary tables –Views are virtual tables. So, if you make them on a temporary base table, this will delete all the views when you remove the table. Simply put when you drop or modify the table, the view also becomes inactive.
- Complex static queries – Views are primarily for simple static queries. But not all the time do we have the situations to use that static query.
For example, you will save time in a query overview view. But when searching for information, this can lead to performance degradation.
- By Order Clause – This can be a turn off as you have to depend on third-party software or software to sort the data.
- Performance degradation– Since Views are imitations of the real-table, the query processor has to translate queries up to the base table. This makes it more time consuming and slow.
- Rules and Defaults– MySQL views do not support rules and defaults. This is quite obvious as views are just imitations. Even if you apply rules and defaults to them, they will either apply to the base table or, simply do not run.
Craig S. Mullin’s Rules
We hope that the information above will help you decide when to use MySQL and when not. But if you are still confused, these three rules by Craigs Mullins can help you decide.
The View Usage Rule
Well, this one should apply to our every action in real life too – it should have a use. So if you are planning on adding a view, first ask yourself – why are you creating it? It should fulfil a requirement, achieve a goal and have an application.
If there are multiple views, they have to be maintained and supported. So they will keep growing unless it becomes impossible to categorize them. The views should always meet one of these uses:
- Provide row and column level security
- Ensure efficient access paths and proper data derivation.
- Ease any complexities from the user
- Provide domain support and solutions that are impossible to accomplish without them.
- Help you rename columns.
The Proliferation Avoidance Rule
Following the second rule helps you keep a check on the number of views you create. We know we should never create anything we don’t need. Yet, sometimes you may decide to create a view that seems right at the moment but might not be needed later.
Making views recklessly can become a problem in the future. So always refer to the proliferation rule. See if it is needed or is another way to achieve the solution.
The View Synchronization Rule
It says that the views you create should achieve the goal you intend and, this is impossible unless they have the correct data. So whenever you make a change in the base table, check that it also reflects in all the views that depend on it. The lack of synchronisation can render the views useless. For this, follow a proper rule that ensures that the correct implementation of all the changes everywhere.
Now when you know both the pros and limitations of MySQL views, look at your data carefully to decide if you want to use them or not.
We hope that the information given above will help you to make the right decision. But if you are still not sure, reach out to us. Our experts will guide you the right way!