MySQL存储枚举如何？ [英] How Does MySQL Store Enums?

问题描述

如果我有这样的表：

CREATE TABLE sizes (
    name ENUM('small', 'medium', 'large')
);

MySQL将在每行中存储这些字符串，或者内部将使用更小的整数知道要引用哪个枚举值？

Is MySQL going to store those strings in every row, or internally will it use something smaller like integers to know which enum value to refer to?

我想在表中使用枚举，但我担心如果将字符串存储在每一行都是浪费的话。 / p>

I want to use an enum in a table but I'm worried if it's as wasteful as storing a string in every row.

推荐答案

它将它们转换为INSERT / UPDATE上的整数，并返回到SELECT上的字符串，因此内部存储为整数，

It converts them to integers on INSERT / UPDATE and back to strings on SELECT so the internal storage is as integers but you don't get exposed to that.

您可以检索整数，如 SELECT mycolumn + 0 。

请参阅 MySQL 5中的ENUM < a>

See ENUMs in MySQL 5

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