Mysql double length error

Question

I want do column for percents..
I need write: 1.00, 2.00, 99.99, 100.. %
How I can use double type for this?

Now I have:

Double(4,2)

But when I write 100 in column I get error:

Numeric value out of range: 1264 Out of range value for column

Answer 1

Look at the answer here (doubleand decimal have the same syntax) or the MySQL manual:

DOUBLE[(M,D)]

M is the total number of digits and D is the number of digits following the decimal point. If M and D are omitted, values are stored to the limits permitted by the hardware. A double-precision floating-point number is accurate to approximately 15 decimal places.

In short, DOUBLE(4,2) means at most 4 digits, with 2 digits after the decimal point. So to support two digits decimals until 100, you need:

double(5,2) unsigned

Note that the unsigned is not mandatory, but can be more performant and safe if you know you won't need negative values.