Mysql存储过程中的不同结果

Question

I have a stored procedure named getvotes(postitem varchar(50),userid varchar(50)) that gets the number of votes given by a user for certain item. The DML statement inside this procedure is

select count(*) from tblvotes where `postitem`=postitem and `userid`=userid;

it gives me the result of 30. But when I run the sql(outside the stored procedure with the same argument values) using

select count(*) from tblvotes where `postitem`=md5(1) and `userid`=md5(1);

the result is 10.

Whats wrong with my query?

Thanks!

Answer 1

Don't use parameter names that have the same name as column names or whatever.

I usually prefix every parameter with p_ and every variable with v_ to avoid such errors.

Answer 2

Check the length of the encryption used for MD5 and User HEX if the hash comparison may fail

select count(*) from tblvotes where postitem = HEX(MD5(1) and userid = HEX(MD5(1));