Should you use enums in database?

Enum types are more convenient for coding. For infrequent releases, or if you often have new/deleted/changed values, use a database table. For static sets of values, or if you release code all the time, use an enum.

Is it OK to have NULL values in a database?

There’s nothing wrong with NULL as long as you know how to deal with them. Creating separate tables to store columns with null values in every scenario is overly misguiding. Nulls are an artifact of the impedance between RDBMS’s and reality.

Can enum be stored in database?

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.

Are enums bad practice?

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.

Should enums be string or int?

2 Answers. The implementation is easy in both cases, and performance differences should be minor. Therefore, go for the meaning : the Strings are more meaningful than numbers, so use the String. +1 I have worked with millions of records.

Are enum good?

Enums provide readability and flexibility over a class with constants. Few other advantages that I can think of enum types. They is always one instance of a particular enum class (hence the concept of using enums as singleton arrives). Another advantage is you can use enums as a type in switch-case statement.

Is it better to use NULL or empty string?

The above output means that count is 0 for null value. Let us check the MySQL version. So it is better to use empty string for database as allowing NULL value forces the system to do extra work and does not give the data that you are looking for.

When should you use NULL?

Allow null only if it makes sense for an object reference to have ‘no value associated with it’. Don’t use null to signal error conditions. The concept of null exists only for reference types. It doesn’t exist for value types.

What is the difference between enum and set in MySQL?

Difference between SET and ENUM. The difference between SET and ENUM is that SET column can contain multiple values and whereas an ENUM can hold only one of the possible values. The SET type is similar to ENUM whereas the SET type is stored as a full value rather than an index of a value as with ENUM.

How do you add an enum to a database?

Existing values cannot be removed from an enum type, nor can the sort ordering of such values be changed, short of dropping and re-creating the enum type. An enum value occupies four bytes on disk.

Are enums good practice?

Best Practice #1: Use enums to eliminate “magic numbers” from your code. Make your code explicit and easy to read. Pitfall #1: Using “magic numbers” leads to hard-to-understand code and business logic errors. Enums will eliminate these issues.

Are enums an anti pattern?

In Java 1.5 enums were introduced to ease handling of constant values. Enums can improve code quality, because they are types that the compiler can check. But they can also be misused and lower the code quality.