![]() For more reference, check the official documentation of MySQL. Thanks for reading! We’ve studied MySQL ENUM data type and how it is implemented. SET is used the same way as ENUM and declared the same way as ENUM. It’s much safer than simply relying on code validation, as the ENUM function will reject any incorrect values at the database level. It is simple to use and efficient, making it a good choice for many applications. MySQL ENUM is a great way to ensure that data entered into your table conforms to a specific set of values. In conclusion, MySQL ENUM is a powerful data type that can be used to store a limited set of values. To get the complete enumeration list, one needs to access the information_schema database.'a list of the continents' is a bad example. Yet Ive never seen a really good reason to use ENUM. But it can be misused by developers who don't understand its downsides. A programming language feature isn't evil. You can not use another table as a priority list. Short, static lists are better suited than department names, because you might want those in a table with other columns. Nothing has changed between MySQL 5.5 and 8.0 to make ENUMs any more or less evil than they were before.ENUM is not SQL standard and only some database systems support it which as a result proves to be difficult when porting to RDBMS.If we want to change the enumeration of the list, then we have to recreate the whole table which proves to be expensive in terms of time.Table data might be compressed, either for a column or an entire row, complicating the calculation of storage requirements for a table or column. Different storage engines represent data types and store raw data differently. It reduces errors that are caused by mistyping the numbers. The storage requirements for table data on disk depend on several factors.Order By priority DESC Code language: SQL (Structured Query Language) ( sql ) Sorting ENUM 2 Advantages of ENUM in MySQL For Descending order- Select name, priority From The values are sorted in ascending order by default. ENUM is MySQL data type and mysql dialect doent support it yet. It looks like the parser doesnt support ENUM type yet. We’ll use the ORDER BY clause to sort enum values in MySQL- Select name, priority From Description: Im working on a cusomized dialect which is a sub set of SQL. Unless strict mode is disabled (not recommended, but see Section 5.1.11, Server SQL Modes ), the definition of a ENUM or SET column acts as a. See Section 11.3.5, The ENUM Type, and Section 11.3.6, The SET Type. The ENUM values are based on the index number and therefore the order of those values will depend on how they were defined in the list. ENUM and SET columns provide an efficient way to define columns that can contain only a given set of values. ![]() Output- ENUM 2 How to Sort MySQL ENUM Values I do understand there are two schools of though and I understand the advantages and disadvantages of both.Code language: SQL (Structured Query Language) ( sql ) ![]() An option also exists to automatically produce a CHECK constraint when the VARCHAR (so called non-native) variant is produced see the Enum.createconstraint flag. Nothing has changed between MySQL 5.5 and 8.0 to make ENUMs any more or less evil than they were before. ![]() Si verifica un errore per i valori che non soddisfano queste condizioni: Un valore ENUM deve essere uno di quelli elencati nella definizione della colonna o lequivalente numerico interno della stessa. This very old article from 2011 and MyQL5.5 still gets referenced again and again by those not liking enums.īut we are using MySQL8.0, on databases that are not that big, like 50 to 60 tables, with 30ish enums columns.Ī few tables have up to a couple millions rows, most are way below 500K rows.Īlmost all enums have fewer than 10 values, and only very few have changed (once) in their life, always to add a new value at the end of the possible values.Īnd we never "suffered" from any disadvantages referenced by the article like storing metadata alongside it, referencing the same values from other tables, etc.ĭespite what the article says at point 2., today, adding a values at the end of the list doesn't update the whole table, but removing a value always update (or at least read) all rows. The Enum type will make use of the backend’s native ENUM type if one is available otherwise, it uses a VARCHAR datatype. Come afferma la documentazione di MySQL: La definizione di una colonna ENUM o SET agisce come un vincolo sui valori immessi nella colonna. So I have a disagreement with a coworker about using enums vs lookup tables. ![]()
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