Method in mysql where the sum float type USES a decimal point

Approach 1: the best approach is to change the float field to decimal(16,6). Specific method: One temporary field can be set, and binary keyword can be combined to copy accurately, etc.
Approach 2: Use the binary keyword. "select sum(binary field name (float type))"
BINARY is not a function but a cast operator that forces the string following it to be a binary string
Example:

    "select sum(a.number*binary(b.price)) as total
        from ler_card as a
        left join ler_items as b on a.itemId=b.itemId
        where user_id=1"