how to create referral code in MySQL

it is very simple trick to get this done. i am using substring(),concat(), and rand() function. MySQL substring function expects 3 parameters substring(string,start_index,length)

select substring("online gurucool",3,4);

as per above example this will return line word from that string.

Don’t waste much time let’s start with trick.

i am going to use below string
ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789
for this method.

select rand() * 36

This is very short and simple select query will give you random number between 1 to 36. then we are going to use this random number as start_index in substring function.

select substring(
    'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',
    ROUND(rand() * 36),1
)

After trickly merging both function as this will return you single random word from above string on every time when you run this query.

finally we use same function in concat() function and create one random string.

select
    CONCAT(
        substring(
            'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',
            ROUND(rand() * 36),1
        ),
        substring(
            'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',
            ROUND(rand() * 36),1
        ),
        substring(
            'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',
            ROUND(rand() * 36),1
        ),
        substring(
            'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',
            ROUND(rand() * 36),1
        ),
        substring(
            'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',
            ROUND(rand() * 36),1
        ),
        substring(
            'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',
            ROUND(rand() * 36),1
        )
    )

When you run above code again and again you will able to see the random code generated.

its on you from where you want use this trick to insert or update referral code.