Question

I have this table:
-id : primary key
-code : CHAR(8) unique

Is there a way in ANSI SQL (or MySQL) of generating a unique numeric code ( can be based on the autonumeric id ) in a single SQL statement for any number of rows? (let’s say 100)

I’m already doing this in a loop in PHP but wonder if it can be done in pure SQL.

Answer 1

To match the current requirements:

SELECT floor(rand() * 90000000) + 10000000; # Will create an eight-digit random number
INSERT INTO table (code) VALUES (floor(rand() * 90000000) + 10000000);
UPDATE table SET code = floor(rand() * 90000000) + 10000000;

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SELECT SUBSTRING( MD5( RAND( ) ), 25 )

Alternatively based on the auto-increment:

SELECT SUBSTRING( MD5(id), 25 ) FROM table

Or to update it:

UPDATE table SET code = SUBSTRING( MD5(id), 25 )