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Should enum be stored in database?
– Having to maintain the enum values both in code and in database. If the enum is updated in code, you need to update it in the database too. For example, let’s say you want to have different role name per state, you would again need to store those in another table in the database and link it to the lookup table.
What is a database enum?
Enum, short for “enumerated,” is a data type that consists of predefined values. A constant or variable defined as an enum can store one of the values listed in the enum declaration. Enums are used in both source code and database tables.
How is enum stored in DB?
First of all, in order to save enum values in a relational database using JPA, you don’t have to do anything. By default, when an enum is a part of an entity, JPA maps its values into numbers using the ordinal() method. What it means is that without customizations JPA stores enum value as numbers.
How does enum work in MySQL?
The ENUM data type in MySQL is a string object. It allows us to limit the value chosen from a list of permitted values in the column specification at the time of table creation. It is short for enumeration, which means that each column may have one of the specified possible values.
Why is enum bad?
The problem with enums is described in Fowler’s Refactoring, where it is considered a code smell. It has nothing to do with type safety, but rather that it forces you to sprinkle switch statements all over your code, thus violating the DRY Principle.
Why is enum evil?
With an ENUM we’re actually storing pieces of data in a place that was only intended to hold crucial information about the model. In short, an ENUM column violates the rules of normalization.
Why is ENUM evil?
Is ENUM a data type?
Enumeration (or enum) is a user defined data type in C. It is mainly used to assign names to integral constants, the names make a program easy to read and maintain.
Is enum good or bad?
An enum is a data type that contains fixed set of constants. An enum is just like a class , with a fixed set of instances known at compile time. Advantages of enum: enum improves type safety at compile-time checking to avoid errors at run-time.
Is using enum bad?
It provides strong type safety. They have some disadvantages at times, but this is really typically related to situations where every possible option is not known in advance. If you have a fixed set of options, such as your example, then strong typed enums are a good thing, and should not be avoided.
Why do you need enums in a database?
By keeping the enum in your database, and adding a foreign key on the table that contains an enum value you ensure that no code ever enters incorrect values for that column. This helps your data integrity and is the most obvious reason IMO you should have tables for enums.
How to create an enum in a CS file?
The T4 generates a .cs file, which means you can have it just query the database and build an enum in a .cs file from the result. Wired up as a pre-build task, it would re-create your enum on every build, or you can run the T4 manually as needed instead. Let’s say you have the following in your DB:
Is it bad to use dynamic enums in C #?
Using dynamic enums is bad no matter which way. You will have to go through the trouble of “duplicating” the data to ensure clear and easy code easy to maintain in the future.
Do you have to specify enums at compile time?
Hope this helps! Enums must be specified at compile time, you can’t dynamically add enums during run-time – and why would you, there would be no use/reference to them in the code? From Professional C# 2008: