保证锁是独家在桌子上也可以阅读

I am writing a web application and came across the problem to keep a value in column that is identical in two rows only and both goes in single batch of execution. One way I came up with solution to read the MAX value in the column and increment by 1. Thus, I end-up writing the procedure to lock the table so that other user should not get the dirty read of MAX value.I am writing a web application and came across