In the world of programming, the SELECT statement is a commonly used command to retrieve data from a database. It allows you to specify which columns you want to retrieve, as well as any conditions for the data to meet. However, there is one aspect of this command that has been a topic of debate among developers - the use of SELECT *.
For those who are not familiar, SELECT * is a shortcut for selecting all columns in a table. It is often used when the programmer wants to retrieve all the data from a table without having to specify each column name. While this may seem convenient, there are several reasons why using SELECT * is not considered good practice.
First and foremost, using SELECT * can significantly affect the performance of your database. When you use this command, the database has to retrieve all the data from every column in the table, even if you only need a few of them. This can result in slower query execution times, especially if the table contains a large amount of data. As a programmer, it is essential to always consider the efficiency of your code, and using SELECT * can have a negative impact on it.
Another reason not to use SELECT * is that it can make your code less maintainable. When you explicitly specify which columns you want to retrieve, it is easier to understand and modify the code in the future. However, with SELECT *, it is not clear what data you are retrieving, making it harder for other developers to work with your code. Additionally, if the table structure changes, your code might break, as it is not designed to handle changes in the column order or new columns added to the table.
Moreover, using SELECT * can also lead to unexpected results. For instance, if a table contains sensitive information, such as passwords or credit card numbers, and you accidentally use SELECT * in your code, all that data will be retrieved, compromising the security of your application. It is always best to be specific with the data you want to retrieve, especially when dealing with sensitive information.
Lastly, using SELECT * can also be a waste of resources. As mentioned earlier, this command retrieves all the columns from a table, even if you only need a few of them. This means that unnecessary data is being transmitted from the database to your application, consuming more network bandwidth and increasing the load on both the server and the client. In a world where resources are becoming more limited, it is crucial to optimize your code to reduce waste.
In conclusion, while SELECT * may seem like a convenient shortcut, it is not recommended to use it in your code. Its impact on performance, maintainability, security, and resource usage outweigh the convenience it offers. As a responsible programmer, it is essential to be mindful of the code you write and always strive for efficiency and best practices. So, the next time you are tempted to use SELECT *, remember the potential drawbacks and opt for explicitly specifying the columns you need instead. Your database and fellow developers will thank you.
