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This article mainly introduces what are the specifications for the use of mysql columns, which have a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, let the editor take you to understand it.

1. Decimal type is decimal, so float and double are prohibited.

Float and double have the problem of loss of accuracy during storage, and incorrect results are likely to be obtained when comparing values.

2. If the stored data exceeds the range of decimal, it is recommended to split the data into integers and decimals and store them separately.

3. Use tinyint/int/bigint by business, accounting for 1-4-8 bytes respectively.

Char/varchar is used according to business.

Example

Demo:mysql > use school; # Select database schoolmysql > create table class6 (class_id integer (5) zerofill, class_name varchar (128), class_teacher varchar (64)); # create table class6 mysql > insert into class0 values (1, 'Class 3, Grade 6', 'Miss Zhang'); mysql > select * from class0 +-+ | id | name | teacher | +-+ | 00001 | Class 6, Grade 3 | Miss Zhang | +-+ 1 row in Set (0.00 sec) Thank you for reading this article carefully. I hope the article "what are the specifications for the use of mysql columns" shared by the editor will be helpful to you. At the same time, I also hope that you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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