在MySQL中使用浮点数存储超过一百万的最大可能值

Question

I am developing a web app in PHP and MySQL and I am trying to store a value in a row that is bigger than 1 million. Whenever I do an insertion into the database, say if I try to insert 45,234,023.34 (no matter what value) it always gets truncated to 999,999.99. I have chosen an unsigned long for that specific column. I know that that is the max value of that datatype as per the following link . Also, I will never have to worry about more than 2 decimals. All my operations will always be 2 decimals no matter what case it is.

Do you guys know how to solve this? What is the correct approach in these situations?

Thank you for your time in advance.

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Update:

Heres the SQL Code:

create table `values` (`id` int unsigned not null auto_increment primary key, `desc` text null, `concept` text null, `value` double null, `created_at` timestamp default 0 not null, `updated_at` timestamp default 0 not null) default character set utf8 collate utf8_unicode_ci

Please bear in mind that the the column I'm interested in is called "value". Thanks!

Answer 1

Don't use FLOAT(m,n) , only use FLOAT .

FLOAT has only 7 digit of precision, so the 10-digit number "45,234,023.34" will lose the last few digits: 45234000 .

Perhaps you want DOUBLE .

Answer 2

Your query should be like this:

create table `values` (`id` int unsigned not null auto_increment primary key, `desc` text null, `concept` text null, `value` DECIMAL(10,2) null, `created_at` timestamp default 0 not null, `updated_at` timestamp default 0 not null) default character set utf8 collate utf8_unicode_ci

Ref Link: https://dev.mysql.com/doc/refman/5.7/en/precision-math-decimal-characteristics.html

Hope this will help!!

Answer 3

At the end I used DECIMAL(12,2). This is because as in the ref docs , this will allow me to have an integer (number to the left of the decimal point) of 10 digits (I only need 9, but I am leaving that extra space in case I decide to use a negative number) and 2 numbers to the right of the decimal point. Tested it throughly in PHP and all operations (ONLY with 2 decimals, anything bigger will be TRUNCATED!) come up right.